Asia Pacific Research Initiative for Sustainable Energy Systems 2013 (APRISES13)

Transcription

1 Asia Pacific Research Initiative for Sustainable Energy Systems 2013 (APRISES13) Office of Naval Research Grant Award Number N DESICCANT DEHUMIDIFICATION APPLICATIONS IN HAWAII PHASE 1 PROJECT SUMMARY Task 7 Prepared For Prepared By Sustainable Design & Consulting LLC & HNEI November 2017

2 DESICCANT DEHUMIDIFICATION TO SUPPORT ENERGY EFFICIENT SPACE CONDITIONING SYSTEMS FOR HAWAII Project Phase 1: Design Study and Project Site Selection Project Deliverable 5: PROJECT SUMMARY REPORT AND PRESENTATION THE GROWING INDOOR HUMIDITY CHALLENGES OF BUILDINGS, AND STRATEGIES TO SOLVE THEM November 27, 2017 FINAL Prepared by: Manfred J. Zapka, PhD, PE James Maskrey, MEP, MBA Prepared for Sustainable Design & Consulting LLC

3 Sustainable Design & Consulting LLC Sustainable Design & Consulting LLC DESICCANT DEHUMIDIFICATION TO SUPPORT ENERGY EFFICIENT SPACE CONDITIONING SYSTEMS FOR HAWAII "PROJECT SUMMARY REPORT AND PRESENTATION; THE GROWING INDOOR HUMIDITY CHALLENGES OF BUILDINGS, AND STRATEGIES TO SOLVE THEM DESICCANT DEHUMIDIFICATION TO SUPPORT ENERGY EFFICIENT SPACE CONDITIONING SYSTEMS FOR HAWAII "PROJECT SUMMARY REPORT AND PRESENTATION; THE GROWING INDOOR HUMIDITY CHALLENGES OF BUILDINGS, AND STRATEGIES TO SOLVE THEM Deliverable 5. FINAL Nov. 27, 2017 Deliverable 5. FINAL Nov. 27, 2017

4 DESICCANT DEHUMIDIFICATION TO SUPPORT ENERGY EFFICIENT SPACE CONDITIONING SYSTEMS FOR HAWAII PROJECT PHASE 1: DESIGN STUDY AND PROJECT SITE SELECTION PROJECT DELIVERABLE NO. 5 PROJECT SUMMARY REPORT AND PRESENTATION THE GROWING INDOOR HUMIDITY CHALLENGES OF BUILDINGS, AND STRATEGIES TO SOLVE THEM Preparing a pilot installation in Hawaii of using Liquid desiccant dehumidification in HVAC to control indoor humidity problems and improve indoor air quality, while saving energy. A Summary Report of the Project Work and Illustrated Presentation FINAL Prepared for November 27, 2017 Prepared by: Manfred J. Zapka, PhD, PE ( 1) James Maskrey, MEP, MBA, Project Manager (2) (1) Sustainable Design & Consulting LLC, Honolulu, Hawaii (2) Honolulu, Hawaii

5 ACKNOWLEDGEMENTS This project is funded by the under grant no. N from the Office of Naval Research. The authors would like to thank both HNEI and ONR for the opportunity to pursue explore the potential for this technology. The authors believe that desiccant cooling applications can be a significant contribution increasing the energy efficiently of building conditioning, providing a better humidity control and foster the implementation of more environmentally friendly ways to provide better occupant indoor environmental quality.

6 Project Summary Overview of Finding and Conclusion TABLE OF CONTENTS TABLE OF CONTENTS EXECUTIVE SUMMARY... 1 PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS The Problem of Increasing Latent Cooling Loads Compared to Heat Gain in Buildings An Effective Approach to Solve the Growing Humidity Problem Conventional Liquid Desiccant Dehumidification Processes Proposed Low Flow Liquid Desiccant Technology Used in the Project Proposed System Integration of LD Technology with Sensible Cooling Technologies Energy Performance of the Proposed Integrated LDAC system Projected Benefits of Improved IEQ and Wellness Created by Proposed LDAC System General Benefits of the Proposed LDAC Technology to Hawaii Design of the LDAC Set up for Initial Tests in a Lab Controlled Environment PART 2: OVERVIEW OF WORK SCOPE OF PROJECT DELIVERABLES 1 THROUGH PROJECT SUMMARY POWER POINT PRESENTATION November 27, 2017 Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC Page iii

7 Project Summary Overview of Finding and Conclusion EXECUTIVE SUMMARY EXECUTIVE SUMMARY This report, Project Task 5: A Summary Report of the Project Work, is Deliverable 5 of the project Desiccant Dehumidification to Support Energy Efficient Space Conditioning Systems for Hawaii Project Phase 1: Design Study and Project Site Selection. Sustainable Design & Consulting (SDC) LLC is performing the work under contract () for (HNEI). This report summarizes the main findings and conclusions and provides an overview about the scope of project work presented in four previously submitted deliverables. Introduction With buildings becoming increasingly energy efficient, their heat gain, which must be removed by space conditioning, switches from mainly sensible cooling, which lowers indoor temperatures, to increased latent cooling loads, which remove moisture. Standard Heating Ventilation Air Conditioning (HVAC) systems typically operate under part load for most of their operating hours. In part load operating conditions, standard HVAC systems can remove a maximum of about 30% of latent cooling loads. When they are oversized, what frequently happens is that the latent load removal capacity under part load can diminish to 15%. In Hawaii s hot and moist climate, the latent loads of buildings are at times as high as 40%, and even higher levels if ventilation air rates are increased to provide better indoor air quality (IAQ). Too high levels of indoor humidity negatively affect air quality and carry health risks for occupants. Too high humidity levels also deteriorate building materials through undesired growth of fungi and increased outgassing of chemical compounds. These humidity related problems have long been recognized as serious risks to occupants and building structures, but cost effective solutions are hampered by the fact that standard AC systems are challenged to deal effectively with elevated indoor humidity levels. The main barrier has been that in standard AC systems, sensible and latent cooling cannot be effectively separated, since these systems are designed to first remove sensible cooling load before latent cooling. Discussion Consequently, an effective approach to avoid indoor humidity problems is to decouple sensible and latent cooling. This can be done through conventional cooling based dehumidification systems; but far more effective are desiccant systems, which do not require cooling the moist supply air to belowdewpoint temperatures. This report proposes to use liquid desiccant dehumidification systems which have significant advantages over their solid desiccant counterparts. Liquid desiccant dehumidification systems have been successfully used for high performance air drying applications, mainly for industrial processes and to a lesser extent for specific building applications, such as hospitals, libraries and museums. Wider liquid desiccant cooling applications for general HVAC systems have been less common, mainly due to operational barriers, such as considerable maintenance and problems of carryover of liquid desiccant solution droplets. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 1

8 Project Summary Overview of Finding and Conclusion EXECUTIVE SUMMARY More recent technology developments of advanced so called low flow liquid desiccant technology have started to overcome these barriers. This new technology has matured to a point where commercial products are now available for dehumidification in general HVAC. These new liquid desiccant systems have significant benefits in terms of lower energy use and the opportunity for use of solar heat or waste heat. This project has identified a suitable liquid desiccant (LD) dehumidification product by the US company AIL Research Inc. for a pilot installation in Hawaii. The LD core system will be combined with energy effective sensible cooling and peripheral systems, which together establish the liquid desiccant air conditioning (LDAC) system. This LDAC system will be tested in a pilot installation; in the first phase in a lab controlled environment, and in the second phase as a regular HVAC unit for a regularly occupied space. The pilot installation will showcase the benefits of the technology and validate projected energy savings as well as improvements to occupant thermal comfort and air quality of the conditioned spaces. Increasing ventilation rates have been reported to be an important factor to achieve higher indoor air quality (IAQ). For standard HVAC, increased ventilation air rates, however, typically come with a significant energy burden due to increased latent cooling demand. The proposed liquid desiccant air conditioning (LDAC) system supports energy efficient dehumidification, even at higher ventilation rates, since overcooling and system reheat is avoided in LDAC systems. An optimum indoor humidity level is at 45% relative humidity (RH). This RH level avoids potentially serious indoor humidity problems and increases the IAQ. An evolving performance metric for buildings is the level of indoor environmental quality (IEQ) and wellness for the occupants. IEQ has many aspects that are directly attributable to the HVAC system performance including thermal comfort (TC) and IAQ. This report presents recent studies that correlate improvements in IAQ and thermal comfort with quantifiable financial gains for companies, which operate in improved indoor building spaces. The financial gains can be expressed in avoiding unhealthy indoor conditions, which in turn lowers absenteeism and health related costs, and improving productivity of employees. Building owners can take advantage of increased net operating income and cap rate as companies and tenants increasingly look for healthy and productive buildings. An example comparison of space conditioning performance using a standard HVAC and an advanced liquid desiccant was carried out for an 8,000 sqft. office space. The projected energy savings of the liquid desiccant system with solar heat (for desiccant regeneration) was predicted at about 30% when compared to standard HVAC system even though the ventilation air rate of the LDAC system was double that of the ventilation rate for the standard AC system. Using recently published expected revenue premiums for office spaces with better IAQ of up to $6,500 per person, the financial benefits of better IEQ was estimated for the company occupying the improved office space. The results, which used a conservative 50% of the suggested $6,500 cost benefits, suggest that the equivalent benefits of higher ventilation rates, improved humidity and IAQ control outperform the projected energy savings by 96% to 4%, respectively. These results put into perspective how an Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 2

9 Project Summary Overview of Finding and Conclusion EXECUTIVE SUMMARY advanced HVAC system, such as the liquid desiccant system, can save energy and create high value by providing a better indoor environmental climate. For Hawaii, energy efficiency HVAC technology and the use of renewable energy for these HVAC systems is essential to achieve the state s energy goals. Providing good energy performance and excellent indoor air quality and thermal comfort is the differentiating quality of the proposed LDAC. This report has two parts. Part 1 discusses the challenges of increased latent loads and proposes an innovative low flow liquid desiccant dehumidification process design. This section describes the benefits of the proposed LDAC to Hawaii, significant energy savings and advanced indoor humidity control, that are essential to the hot and humid climate of Hawaii. Part 2 summarizes the scope of project work contained in four previously submitted deliverables. Summary Project Conclusions and Recommendations: The wider use of green building technologies helps Hawaii to achieve its important goal of reducing energy. On the flip side, in more energy efficient buildings that are tightly sealed when air conditioned, humidity problems can arise, especially in Hawaii s hot and humid climate. This causes significant risks to occupants and the building itself, as healthy indoor relative humidity levels are often not effectively maintained with standard HVAC systems. New HVAC strategies can provide safe removal of increasing humidity loads and, at the same time, significantly increase energy efficiency with the use of renewable thermal energy in building HVAC. The HNEI and SDC project team has conducted a significant research effort in new types of HVAC systems that are based on the evolving low flow liquid desiccant technology. The new HVAC technology is called Liquid Desiccant Air Conditioning (LDAC). LDAC systems can reduce energy imported to Hawaii as well as carbon emissions. The average level of these savings is 30%, but can be as high as 80% when all cooling loads are provided by thermally driven chillers. In addition, the LDAC technology offers significant financial benefits to companies as they can reduce health related costs and boost office productivity with a healthy indoor environment. These financial benefits can surpass energy cost savings many times over. LDAC technology clearly outperforms standard HVAC in achieving good indoor environmental quality, through improved ventilation and advanced humidity control. It also significantly improves indoor air quality and thermal comfort. LDAC must be field tested in Hawaii to optimize its performance in the hot and humid climate of Hawaii. The project team of HNEI and SDC has prepared the design to install a pilot LDAC system as a key first step for broader deployment of LDAC in Hawaii. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 3

10 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Fundamental Challenges of Increasing Latent Cooling Loads in High performance Buildings and the use of Liquid Desiccants for Energy Efficient and Advanced Humidity Control and IEQ improvements. 1.1 The Problem of Increasing Latent Cooling Loads Compared to Heat Gain in Buildings Starting in the late 1970s, and in response to national energy crises, a steady pattern of improved energy efficiency in buildings emerged. National energy codes and guidelines prescribed improvements in buildings to reduce energy consumption. State governments developed or adopted even more strict energy codes into their own regulations. Figure illustrates the relative performance improvements due to mandated energy codes for buildings and building technology compared to a 1975 baseline. Figure shows the historical and the predicted reduction of energy use in buildings, as required by different energy codes. Figure 1.1.1: Historical and future predicted development of energy efficiency based on energy codes The magnitude of energy use in buildings is closely related to the energy required for space conditioning. Internal and external thermal gains require mechanical cooling energy to remove heat gain from the conditioned spaces. Figure illustrates the types of external and internal thermal gains in buildings that increase energy demand for space conditioning. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 4

11 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Figure 1.1.2: Typical Heat gain processes in buildings The indices 1 A through 1 G are cross referenced and further described in Section 1 The primary improvements to offset these heat gains 1 A through 1 G in Figure include: (1 A) (1 B) (1 C) (1 D) (1 E) (1 F) (1 G) High performance windows reduce the conductive and radiative heat transfer from windows through reduction of solar gain and adding insulation to lower conductive gain. Shading of windows reduces the solar gain by avoiding heat transmittance into the building. Increased wall insulation through adding higher R value walls layers reduces conductive heat transfer. Sealing the envelope and tightening envelope penetrations lowers the convective heat transfer. Effective envelope sealing also minimizes intrusion of moisture into the building. Cool roof technology significantly reduces heat gain through roofs and attics. These technologies include a range of measures that includes reflective and radiative roof materials, radiant barriers and attic ventilation. High performance appliances and equipment reduce the indoor electricity demand and therefore the indoor heat gain. High performance lighting, such as LED and CFL, reduces lighting related energy use and thermal gain. The increased use of controlled daylighting augments electric lighting at no energy cost. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 5

12 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS The improvements in building technologies described serve to reduce the sensible cooling loads which must be managed by HVAC systems. Conversely, the latent cooling loads remain unchanged. With effective sealing of the envelope and relatively constant indoor moisture sources, future latent loads are projected to either remain constant, or increase should the ventilation rates increase. Figure illustrates the projected significant decrease in sensible heat gain and the slight increase in latent cooling loads. Figure (a) provides a qualitative description of the distribution of sensible and latent heat loads. Figure (b) shows the latent heat ratio (LHR, the ratio of latent to overall cooling load) which when added to the sensible heat ratio (SHR,) is equal to one. The more frequently used SHR is defined as the ratio of the sensible cooling load over the sum of the sensible and latent cooling loads. Sensible or Latent Heat [BTU/h] Sensible Heat Ratio [SHR] Latent Heat Ratio [LHR] 0 Time scale (arbitray) Sensible Heat Latent Heat Time scale (arbitray) SHR LHR 0.2 (a) Distribution of sensible and latent cooling loads (b) Sensible and latent heat ratio Figure 1.1.3: Increase of sensible and latent loads over time and decrease of latent heat ratio Standard HVAC systems are designed to primarily remove sensible cooling loads and manage the latent cooling load in the process. With an increasing latent heat ratio, and therefore lower SHR, standard HVAC systems are not well equipped to remove the moisture, especially under partial load conditions. Partial loading is the dominant operational condition under which HVAC systems operate. Under partial loads, cooling coils will cycle in an ON OFF pattern, controlled by temperature set points. With supply air passing over cooling coils that are above dew point, and the evaporating of condensate from wet coils, the efficiency of latent cooling load removal is reduced. Figure shows a reduction in moisture removal performance for standard HVAC systems under higher latent heat ratios and lower sensible heat ratios. Figure suggests that standard HVAC systems can contribute to unhealthy indoor conditions due to high relative humidity (RH) levels resulting from the SHR decrease. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 6

13 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Figure 1.1.4: Indoor RH vs. building Cooling Load SHR with conventional unitary AC equipment The figure describes that with decreasing SHR and increasing LHR, standard unitary system do not effectively manage the latent cooling load, thereby increasing the indoor RH levels to potentially unhealthy values. effectiveness with lower SHR Source: TIAX (2003) Matching the Sensible Heat Ratio of Air Conditioning Equipment with Building Load SHR Conclusions: As buildings become more energy efficient, sensible heat gains diminish while latent cooling loads remain or are likely to increase with increasing ventilation rates. Consequently, humidity related health hazards and moisture caused building damage can be phenomena that will increase as buildings become more energy efficient and tightly sealed, thus requiring controlled ventilation. Standard HVAC systems are ill equipped to manage higher latent load ratios, necessitating new technologies and operational procedures to counter this trend An Effective Approach to Solve the Growing Humidity Problem Standard HVAC removes the latent load in the ventilation air by passing the air over cooling coils that are maintained below dewpoint temperatures. The moisture in the air is thus removed as condensate which drains from cooling coils. When passing over the coils, the air also removes sensible heat. If the indoor sensible heat gain is lower than the cooling capacity of the supply air, the cooled air must be reheated before entering the space to avoid overcooling and negatively affecting thermal comfort of the occupants. System reheat consumes significant heat energy, often supplied by natural gas, but sometimes as electricity where natural gas is not readily available. Standard HVAC systems thus cannot readily separate sensible from latent cooling load removal. Typically, standard HVAC systems control cooling cycles with a HIGH to LOW temperature setpoint Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 7

14 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS band, rather than humidity. Precise indoor humidity control would require HVAC systems that (1) control BOTH operative temperature and humidity independently and (2) provide correctly sized sensible and latent removal. Figure shows a basic process diagram of (a) standard HVAC operation with simultaneous sensible and latent cooling load removal and (b) advanced HVAC which decouple sensible and latent load removals. (a) standard HVAC operation with simultaneous sensible and latent cooling load removal (b) advanced HVAC that decouples sensible and latent load removal. Figure 1.2.1: Basic processes of coupled and decoupled sensible and latent cooling load removal Conventional cooling based dehumidification systems have the disadvantage of requiring reheating the cooled air. Desiccant dehumidification has the advantage that the moisture in the supply air can be removed at above dewpoint temperature and therefore no reheat is required. In addition, desiccant dehumidification can use solar or waste heat for its system regeneration process, thereby significantly reducing electric energy needs. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 8

15 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Conclusions: Standard HVAC systems rely on simultaneous sensible and latent cooling load removal. This combined heat removal process has been adequate with high SHR buildings, but is not well suited for HVAC applications when sensible cooling loads decline as buildings become increasingly energy efficient. A suitable mitigation of insufficient latent cooling load removals is decoupling sensible and latent cooling loads through separate controls and dedicated system components that independently lower temperature and remove water vapor from conditioned spaces. Using liquid desiccant dehumidification avoids energy for reheat and separates the dehumidification process from the sensible indoor air temperature. 1.3 Conventional Liquid Desiccant Dehumidification Processes There are two desiccant technologies, which are presently used in HVAC applications; solid and liquid desiccants. Solid desiccant systems are more widely used in building conditioning, especially in the form of desiccant wheels. Liquid desiccant systems have primarily been used for specific dehumidification processes, such as in special industries or selected institutional buildings with the need for precise humidity control, including hospitals, libraries and museums. The liquid descant dehumidification process has been identified as having advantages regarding energy and IEQ properties over solid desiccants and was selected for this project. Figure shows a conventional liquid desiccant dehumidification system, operated as a packed column with external cooling and regeneration, into which the liquid desiccant solution is injected. As the desiccant solution trickles down the packing elements, moist air moves in counter flow direction. Water vapor in the moist air migrates towards the surfaces of the desiccant solution, thereby drying the air. As the desiccant solution becomes saturated with water vapor, it is pumped to the regenerator where heat energy removes the moisture from the desiccant solution with its hot and dry scavenger air stream. Figure illustrates the basic thermodynamic processes of liquid desiccant dehumidification. Figure (a) shows the three main process steps in the liquid desiccant dehumidification process which are sorption, desorption and cooling. Figure (b) illustrates sorption process, also called absorption. The water vapor pressure in the air is higher than at the desiccant solution surface, thus moisture is absorbed into the desiccant. As more water vapor is absorbed by the desiccant, water vapor pressure declines in the air and increases at the desiccant surfaces. The desiccant solution becomes saturated. Absorption heat is then liberated increasing the temperature of the desiccant solution. The heat of absorption has to be rejected, typically by an evaporation cooling tower. Figure (c) illustrates the desorption process in the desiccant regenerator. The desiccant solution is pumped from the absorber to the regenerator and comes into surface contact with a heated scavenger air flow. Water vapor pressure of the liquid desiccant surfaces is higher than in the heated scavenger air. Consequently, water vapor moves from the desiccant solution to the air, driven by the water vapor pressure differential. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 9

16 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Figure 1.3.1: Conventional liquid desiccant dehumidification system, operating as a packed column with external cooling and regeneration (a) Three main process steps in the desiccant dehumidification are of sorption, desorption and cooling (b) Sorption process: humidity (water vapor) moves from the humid air to the desiccant because water vapor pressure is higher in the moist air. (c) Desorption: humidity moves from the desiccant to the hot scavenging air because water vapor pressure is higher at the desiccant surface Figure 1.3.2: Basic processes in liquid desiccant dehumidification Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 10

17 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Conclusions: Liquid desiccant dehumidification has been used successfully for several decades to provide advanced dehumidification in certain industrial and institutional applications. Liquid desiccant systems have advantages over solid desiccant systems for HVAC applications that include energy efficiency, use of renewable energies and better indoor air quality. 1.4 Proposed Low Flow Liquid Desiccant Technology Used in the Project Conventional liquid desiccant dehumidification systems have higher maintenance and operational challenges compared to standard HVAC technology. This has been a barrier to their wider use in general HVAC applications. A new liquid desiccant dehumidification technology, the so called low flow desiccant process, was developed to avoid these problems. The new low flow liquid desiccant technology has internally heated and cooled process vessels, and a significantly lower desiccant flow rate. This avoids desiccant droplet carryover to the conditioned spaces and provides for smaller process vessels. The new liquid desiccant technology also requires less maintenance and is more energy efficient. Figure shows the low flow liquid desiccant technology developed by AIL Research Inc. (AILR). The AILR product was selected for this project after evaluating six liquid desiccant vendors. The figure shows a schematic rendering and a photo of an internally cooled absorber. Unlike the packed columns type process vessels of conventional systems, the new low flow technology uses evaporative matrix in the absorber and regenerator. Desiccant solution slowly flows downwards through the evaporative matrix while being in contact with air passing through it. Copper tubes integrated into the matrix, which contains a flow of cooling or heating water, provide the internal heat sink and source for the absorber and regenerator heat, respectively. Figure shows selected previous commercial and demonstration HVAC projects with AILR liquid desiccant technology products. The figure shows (a) packaged LDAC systems containing absorber and regenerator, (b) and (c ) LDAC units with solar thermal systems that provide heat to the regenerator. Presently, AILR s LDAC technology is not widely used, since low flow liquid desiccant dehumidification in building HVAC is an evolving and emerging innovative technology, and is therefore unfamiliar to most operators. But the benefits of this technology, which are discussed in more details later in this this report, are particularly compelling for the hot and humid climate and unique energy market of Hawaii. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 11

18 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS (a) AILR low flow" LD dehumidifier with three main components: the conditioner, the regenerator and the interchange heat exchanger (IHX) Figure 1.4.1: The AILR low flow liquid desiccant technology (b) The AILR patented absorber and regenerators design. Cooling tube are imbedded into an evaporative medium (a) LDACs installed at supermarkets in California, in Seal Beach and the other in Tustin. (b) (Above) An AILR LD unit was installed at a supermarket in Hawaii. The process heat for desiccant regeneration was supplied by solar thermal system. (c) (Left) An AILR LD unit was installed Tyndall AFB. Hot water is provided by a 1,350 square foot array of evacuated tube solar collectors. Figure 1.4.2: Selected previous commercial and institutional projects with AILR liquid desiccant technology products. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 12

19 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Conclusions: The liquid desiccant technology of AIL Research Inc. was selected from several vendors and technology developers. AILR s Low flow liquid desiccant technology is more suitable for general HVAC applications. The AILR technology has been used in several commercial and institutional projects and has matured to a point where a wider market entry can be anticipated Proposed System Integration of LD Technology with Sensible Cooling Technologies The liquid desiccant (LD) system dehumidifies the supply air to such an extent that the indoor latent load, e.g. the water vapor introduced to the conditioned space, can be safely absorbed by the dry air and expelled with the discharge air. The LD system does not, however, remove sensible heat, and therefore separate sensible cooling technologies must be installed to reduce the temperature in the conditioned space. In this technology comparison it was assumed that the indoor air has been sufficiently dehumidified, e.g. the dew point has been sufficiently lowered, that the chilled water supply to the sensible cooling units remains above dew point and therefore condensation does not occur. During the project the following sensible chilled water cooling technologies were considered: 5 A. 5 B. 5 C. Air handling units (AHU) provide sensible cooling to the primary air supply. AHU units are installed inside the supply air duct system. The cooled supply air must be sufficiently large to remove the sensible and latent load from the indoor space. If the ventilation air cannot be separated from recirculated air flow, the AHU configuration does not decouple sensible and latent load removal. Fan coil units (FCU) have internal air fans that recirculate indoor air over cooling coils. The sensible cooling by the FCU can act independently from the dehumidification process, which is provided by cooling coils in the primary supply air. The cooling capacity of the FCU is dependent on temperature differentials of cooling coils and indoor air as well as air flow rate through the FCU. Chilled ceilings (CC) operate primarily on radiant, and to a lesser extent, on passive convective heat transfer. The main CC performance parameter is the size of the radiant ceiling area. The temperature of the CC cannot be too low because this would establish a radiant asymmetry, that is, the temperature differential between the radiant ceiling and the mean radiant temperature (MRT). A too high a radiant asymmetry would create thermal discomfort (a chill) to occupants. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 13

20 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS 5 D. 5 E. Active chilled beams (ACB) provide sensible cooling load by using the primary supply air to induce recirculating movement of indoor air over cooling coils inside the ACB. ACBs have been frequently used in HVAC installations. Since the ACB operates requires a significant minimum primary supply air flow rate for indoor air induction, sensible and latent load removal cannot be completely decoupled. Passive chilled beams (PCB) are similar to ACBs, but they do not use primary supply air to induce indoor air flow over the cooling elements inside the chilled beam. The PCB technology relies solely on density induced air movement of cooler and denser sinking from the PCB. The PCB has no internal fan nor a connection to the primary air duct. Conventional PCBs have a lower heat transfer rate than ABSs, but newer designs of PCBs have significantly improved the thermal performance. These new PCB designs have significantly increased both the convective as well as the radiant heat transfer rates. Using PCBs allows complete decoupling of sensible and latent cooling load removal. Option 5 E, the passive chilled beam, was selected for this project as thermal technology to remove indoor sensible cooling loads. Figure shows the PCB technology selected for the project, the Barcol s Radiant Wave product. Radiant Wave panels will be suspended below the ceiling. Placing the panel at a prescribed distance from the ceiling increases the convective heat transfer rates and also provides a significant portion of the cooling capacity as radiant heat transfer. Cross section through Barcol Radiant Wave Barcol Radiant Wave PCB technology Figure 1.5.1: PCB technology selected for the project, Barcol Radiant Wave Figure shows a schematic of the preferred configuration of the proposed LDAC system with liquid desiccant dehumidification and sensible cooling using passive chilled beams (PCBs). In Figure 1.5.2, a water to air heat exchanger is added downstream of the LD unit to allow a controlled removal of sensible heat from the dried air stream coming out of the desiccant absorber unit. Figure also illustrates the use of a ceiling fan to add cost effective convective cooling of occupants. Using ceiling Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 14

21 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS fans in the proposed LDAC system is more prudent than using ceiling fans in spaces with standard HVAC, since ceiling fans can indirectly cause humidity problems in standard HVAC decreased ON time. When operating ceiling fans, occupants tend to increase the temperature control set point thereby making ON OFF cycling in standard HVAC systems more likely, resulting in insufficient dehumidification. In the proposed LDAC system, however, the level of dehumidification is controlled independent of the temperature set point, therefore increasing the set point will not affect the humidity removal. Figure 1.5.2: Configuration of the LDAC system with desiccant dehumidification and sensible cooling using passive chilled beams (PCBs). Conclusions: Several sensible cooling technologies were considered for the proposed LDAC system. An innovative passive chilled beam (PCB) design with high heat transfer rates was selected to provide sensible cooling load removal. The advantages of the PCB include good energy performance, easy installation without connection to supply air ducting and complete decoupling of sensible and latent loads Energy Performance of the Proposed Integrated LDAC system The proposed LDAC system provides significant electrical energy savings over standard HVAC systems. The following are the main factors that improve energy efficient operation: Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 15

22 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS 6 A. The LD dehumidification system uses only a limited amount of electricity for fans and pumps. The system uses thermal heat for desiccant regeneration and evaporative cooling for the heat sink of absorption heat of the absorber. The LD system does not use a vapor compression cycle. The heat for desiccant regeneration would preferably come from a solar thermal system or provided by waste heat. Figure illustrates the energy advantage of the LDAC system over standard HVAC with cooling based dehumidification. Figure shows the psychrometric process of a standard HVAC system (Path 1) where the air is cooled to the desired dew point and then reheated to avoid thermal discomfort for occupants in the conditioned space. The LDAC system (Path 2), on the other hand, does not require as much energy to attain the target indoor temperature and humidity, since overcooling and reheating is avoided. Considering the basic psychrometric process and required reheat illustrated in Figure 1.6.1, the energy savings of the LDAC over the standard HVAC is 33%. Figure 1.6.1: Psychrometric performance of LDAC and standard HVAC The standard HVAC requires 64.8 tons ( tons) along Path 1 The LDAC requires 43.2 tons along Path 2; this is a saving of 33% 6 B. The passive chilled beams do not use electric energy directly, but only indirectly by receiving quantities of chilled water provided by water pumps. Moving heat from the room to an external heat sink by relatively small volumes of cooling water is much more energy efficient than moving larger volumes of cooled air. The passive chilled beams also do not have to rely on primary supply air to induce air movement over the internal cooling elements. This saves fan energy, since the indoor air movement initiated by the PCB relies on density induced air movement and not on forced air. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 16

23 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS 6 C. 6 D. 6 E. 6 F. The sensible cooling units require heat sinks which can be supplied by either conventional vapor compression (VC) chillers or be thermally driven chillers, such as adsorption chillers. Using VC chillers as the heat sink for the proposed LDAC can take advantage of a better energy performance of the chiller, since the chiller can operate at higher chilled water temperatures, which increases the thermal performance. Using adsorption chillers requires installation of solar thermal systems with a thermal buffer storage tank. A prudent system design using adsorption chillers would implement some form of stand by heat source to provide for heating water supply interruption due to intermittent availability of solar heat. Ceiling fans provide very cost effective and energy efficient convective cooling for occupants. Evaporative cooling was investigated but not selected because of the limited efficiency caused by the typically humid, high wet bulb temperatures in Hawaii s climate. Using the discharged air from the conditioned space, which has a lower RH than the outside air, is an option, but provides only limited sensible heating capacity. Enthalpy recuperation (e.g. total energy recovery) exchanges sensible and latent cooing loads between the discharge and supply air flows. This can save significant amounts of energy. Since the target indoor and outside dry bulb temperatures do not differ significantly in the proposed LDAC, only the latent heat exchange would be considered as a viable energy saving proposition. New enthalpy recuperation technologies use low maintenance and costeffective membrane technology for the transfer of humidity between discharge and supply air. As a system sizing example, the project evaluated the energy performance of the proposed LDAC system serving an 8,000 sqft. office sample space, and compared the energy use with a standard HVAC system. The LDAC used a ventilation flow rate that was twice that of a standard HVAC based on minimum ASHRAE ventilation rates. Using the energy saving features 6 A through 6 D, as defined above, the predicted energy savings of the proposed LDAC were calculated. Figure shows the results and the comparison of annual energy costs between a standard HVAC and the proposed LDAC system. The figure indicates a $9,000 energy cost saving, using energy prices typical for Hawaii. The results of the energy analysis suggested that the proposed LDAC would save approximately 30% of electric energy compared to the baseline of a standard HAC system. These predicted energy savings are similar to energy savings reported by a 2014 NREL study for several installations of AILR liquid desiccant systems. The energy savings of the different AILR LDAC systems reported by NREL are shown in Figure 6.3. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 17

24 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Energy Costs / Savings $40,000 $30,000 $20,000 $10,000 $30,000 $9,000 $21,000 Figure : Comparison of annual energy costs between a standard HVAC and the proposed LDAC system. The energy calculation for a sample 8,000 sqft office. $0 Conventional DX HVAC system; min. ventilation rate Energy costs Proposed LDAC system; double min. ventilation rates Energy savings Figure 1.6.3: Predicted energy savings of several AILR liquid desiccant systems reported by NREL The equivalent carbon emissions were evaluated for two alternative system configurations of the proposed LDAC, one (a) with a conventional vapor compression chiller and the other (b) with a thermally driven adsorption chiller, for sensible cooling load removal. These carbon emissions were then compared with carbon emissions of a standard HVAC system. Figure shows that the alternative LDAC system configurations (a) and (b) were 42% and 83% below the equivalent carbon output of the standard HVAC, respectively. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 18

25 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Carbon Dioxide Equivalent [% of baseline] 100% 80% 60% 40% 20% 58% 100% 17% Figure 1.6.4: Percentage comparison against the baseline carbon equivalent emission of the convention HVAC system 0% 1. Proposed LDAC system, with vapor comprestion chiller 2. Standard (baseline) AC 3. Most efficient LDAC system all solar Conclusions: The proposed LDAC system with vapor compression for sensible cooling load removal estimated a 30% energy savings relative to a standard HVAC system. The LDAC system provided a twice as high ventilation air flow rate than the standard HVAC. Therefore, comparable energy savings should be even larger. The projected energy savings are consistent with performance evaluation of several AILR LDAC systems, published by NREL in The projected carbon emission reduction of the proposed LDAC was evaluated as 42% and 83% relative to standard HVAC technology Projected Benefits of Improved IEQ and Wellness Created by Proposed LDAC System In the past, high performance buildings were primarily evaluated by the level of reductions in energy use and environmental impact. Occupant comfort and wellness were considered somewhat relevant, but typically not quantifiable as a primary decision parameter. This has changed, and increasingly terms such as heathy and productive buildings and wellness in buildings are growing in importance when quantifying the benefits of green buildings. While sustainable buildings were often promoted as good for the environment, healthy and productive buildings that offer excellent indoor environmental quality have direct and quantifiable financial benefits for companies and building owners/operators. A healthy and productive indoor environment has been shown to reduce absenteeism and increase productivity of employees. Retaining important talent and reducing employee turnover saves companies far greater costs than is spent on Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 19

26 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS energy. These human resources related factors have been proven as being directly and positively affected by high quality indoor environmental conditions. Figure presents two health building standards, (a) the 9 Foundations for Healthy Buildings developed by the Harvard Healthy Building Program, and (b) the WELL Building Standard. The Harvard Health Buildings Program developed projected cost savings and increased revenues through improved indoor environmental quality. Figure (c) presents how total office related costs for companies are distributed between personnel cost, rent & technology and energy. Figure indicates that energy costs play only a minor cost factor whereas personnel costs make up the lion s share of the cost of doing business. This distribution of cost indicates that even small reductions in personnel costs or increases in employee productivity can have a larger impact than reductions in energy costs. Figure shows the optimal value of indoor relative humidity (RH) of 45%, which should be maintained to avoid humidity related health problems as well as problems to the building itself. (b) The WELL Building Standard; provides standards for healthy and productive buildings (a) Harvard Healthy Building Program; Guidelines for healthy and productive buildings Tangible financial benefits through IEQ and Wellness (c) Typical distribution for the cost of doing business for office workers Figure 1.7.1: IEQ and Wellness in buildings become tangible benefits for companies Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 20

27 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Relative Humidity Organisms Bacteria Viruses Fungi Mites Allergic Rhinitis & Asthma Respiratory Infections Optimum level of RH Figure 1.7.2: Levels of activity of harmful organisms and chemical interactions as a relationship of indoor RH The value of 45% RH has been identified in the literature as optimum indoor RH Chemical Interactions Ozone production The Harvard estimates specifies an average annual $6,500 per employee increase in revenues and cost reduction when indoor air quality is improved through increased ventilation. The same example case of an 8,000 sqft office space was used to estimate financial benefits from improved indoor health and wellness conditions. For this estimate, the following aspects of indoor environmental improvements were considered based on the performance characteristics of the proposed LDAC: Increasing the ventilation rate of the conditioned space by 100% over ASHRAE recommended minimum ventilation rates for office spaces. Using a dedicated outdoor air system (DOAS) which avoids recirculation of air as used in standard HVAC systems. Pollutants and pathogens are directly transported to the outside by the DOAS system, and distribution of these within the conditioned space through recirculated air is avoided. Precise humidity control at an optimum 45% relative humidity level increases the indoor air quality, since 45% is the RH level that avoids the growth and hazards cased of harmful pathogens (refer to Figure 7.2) Advanced filtration, removal of pollutants and pathogens is provided by the LDAC system, where the liquid desiccant solution acts as advanced filtration and disinfection devices. For the example 8,000 sqft office, increased revenue and cost reductions due to reductions in building related sickness and absenteeism, as well as increased productivity, was calculated. We used a conservative 50% of the Harvard suggested $6,500, which equals $3,250 per employee increase in revenues. The results of this analysis for the 8,000 sqrt. office space are shown in Figure The results indicate that the increased revenues or avoided costs of building related sickness and absenteeism of employees, and the increase in productivity through increased IEQ and wellness, is significantly greater than the energy savings by the LDAC. The calculated energy cost savings are only 4% of total cost savings, compared to the 96% of total cost savings represented by the better productivity and reduced health costs for employees based on better IEQ and wellness. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 21

28 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS While energy savings are essential for Hawaii s future energy goals, providing a high indoor environmental quality to occupants creates direct and significant incentives to companies and building owners and operators to pursue Green Buildings. Cost Savings / Increased Revenue $250,000 $200,000 $150,000 $100,000 $50,000 $9,000 $230,000 Percentage of Cost Savings / Increased Revenue 100% 80% 60% 40% 20% 4% 96% Figure 1.7.3: Comparison between calculated energy cost savings and reduced costs through better IEQ and wellness The calculations are based on the following assumptions: 8,000 sqft. office 110 sqft. per person 50% of Harvard figure of $6,500 per person productivity gain and les health risk = $3,350 per person $0 0% Calculated energy cost savings Calculated increased productivity through better IEQ and Wellness Conclusions: With high indoor environmental quality through advanced LDAC systems, companies and building owners / operators can secure significant financial benefits, including the avoidance of building related health problems and increasing the productivity of employees. For an example office space using LDAC, calculated increased revenues and avoided costs through improved IEQ were compared to the energy savings. Resulting savings using LDAC were as 96% and 4% of total savings, respectively. For Hawaii, energy savings are essential to achieve the state s imposing energy reduction goals, but not at the expense of healthy and productive indoor environments. Combining energy savings with the improvement of the financial performance of the companies that provide a quality indoor environment makes the proposed LDAC technology especially attractive. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 22

29 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS 1.8 General Benefits of the Proposed LDAC Technology to Hawaii Hawaii manifests several challenges with respect to space conditioning. The climate is hot and humid and most of the HVAC systems installed are based on design strategies that are not optimized for the climate, nor provide optimal indoor environments for building occupants. People in Hawaii generally like openness of spaces and the affinity to the outside climate. Adaptive comfort, a concept promoted by ASHRAE for naturally ventilated spaces, relies on occupant s adaptation to outside climatic conditions and their openness to spending time in spaces with higher indoor temperatures than typically found in spaces conditioned by standard HVAC. The proposed LDAC system could provide a comfortable indoor environment for Hawaii with higher air temperatures than targeted by standard HVAC, but with optimum indoor relative humidity levels. A sufficiently high ventilation rate would provide a sense of natural freshness and create higher indoor air quality by removing indoor odors and pollutants. Avoiding high recirculation of indoor air through a dedicated outside air supply (DOAS) would avoid recirculation of stale and possible polluted indoor air. Annoying noise levels would decrease as less air is flowing through air ducts. The absence of mold issues and other pathogens through a precise maintenance of indoor RH would solve a wide range of indoor air quality issues related to humidity. The tendency to overcool conditioned spaces will be mitigated. In short, the proposed LDAC technology can provide a conducive indoor environment while at the same time save energy. The proposed LDAC technology will save energy because no fossil based energy is wasted for reheat, since solar or other environmentally friendly thermal heat sources could be used. The proposed LDAC especially caters to the use of energy saving naturally occurring heat sinks, such as deep well or seawater air conditioning (SWAC). Larger SWAC systems are currently under design development for several locations in Hawaii. The use of SWAC (or a deep well derived supply of cold water) for the proposed LDAC system would be significantly more cost effective than current SWAC designs serving standard HVAC. Deep cold seawater could be extracted form a shallower depth than considered for the present SWAC designs. Using cold seawater pumped from significantly shallower depth, and at a lower flow rate, would significantly lower the price of the most expensive system part of a SWAC system, which is the cold seawater pipe. Using SWAC in combination with solar operated LDAC would create the most energy efficient HVAC system possible for the local climate. Conclusions: On a larger scale, the proposed LDAC system can create significant value for Hawaii. LDAC s can save significant amounts of electric energy while at the same time create an indoor environment that resembles conditions which are preferred by people living in Hawaii. LDAC helps to reduce unhealthy conditions which are frequently related to excess humidity. The LDAC can shift the energy use from imported energy sources to locally available, renewable thermal and solar energies. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 23

30 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS 1.9 Design of the LDAC Set up for Initial Tests in a Lab Controlled Environment While the LDAC technology has already been installed in commercial and institutional buildings, it is still an evolving technology. In particular, the combination of liquid desiccant dehumidification with the type of energy efficient sensible cooling technologies selected for the pilot installation is creating a new type of HVAC application. This newness requires pilot installations to develop the operational experience and safeguard that all system parts operate as planned. It was therefore decided to install a smaller LDAC system at a pilot location in Hawaii, to test the system under real world conditions for an extended time, preferably at least a year, to cover all relevant seasonal conditions. The planned pilot installation will occur in two phases, called Project Phase II/A and II/B. In the Phase II/A the LDAC system will be tested in an 800 sqft laboratory space. This first phase will test the thermodynamic performance of the LDAC unit and how an indoor space adjusts to changing thermal and humidity conditions controlled by the proposed LDAC system. During Phase II/A, only the research staff and possibly a limited group of people will occupy the 800 sqft. lab space during the initial test program. The main objective of Phase II/A is to gain operational experience and provide valuable design guidance to select the right pilot location for the Phase II/B. In Project phase II/B, the LDAC will be installed at a pilot location where the system will operate as a normal HVAC system, providing the occupants with sensible and latent cooling and providing ample ventilation air. The objective of Phase II/B will be to verify that the LDAC technology can indeed provide outstanding indoor comfort and healthy spaces while at the same time saving energy. The design of the proposed test set up for the initial tests in the 800 sqft. lab during Phase II/A has been completed. Several details, such as shop drawings, will be completed during installation. The design is presented in project Deliverable No. 4. Figures and present two example drawings which are part of the complete design package in Deliverable 4. The concept design of the proposed test set up in Phase II/B was developed. The more detail design of the test set up will need to be done at a later stage, after the pilot location has been selected. Conclusions: Verification testing in Hawaii of the proposed LDAC system is essential to confirm the predicted performance and benefits of the LDAC technology. Testing of the LDAC technology under real world conditions will occur at a pilot installation in Hawaii as presented in Project Deliverable No.4 These tests will occur in two phases, where the first phase will be initial tests in an 800 sqft space under a controlled lab environment without regular occupants. The second test phase will be an installation in a regularly occupied conditioned space, preferably an office, classroom or library. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 24

31 Project Summary Overview of Finding and Conclusion PART 1: SUMMARY REPORT OVERVIEW OF MAIN FINDING AND CONCLUSIONS Figure 1.9.1: Process and instrumentation diagram of the proposed LDAC test set up in the space LAB 123. The full size sheet is presented in Deliverable No. 4, Appendix A Figure 1.9.2: Section B B, overview of room LAB 123 and detail around the installed LDAC unit; The full size sheet is presented in Deliverable No. 4, Appendix A Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 25

32 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 PART 2: OVERVIEW OF WORK SCOPE OF PROJECT DELIVERABLES 1 THROUGH 4 Figure 2.1 Cover images of the four project deliverables. Figure 2.1: Cover pages of Project Deliverables 1 through 4 Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 26

33 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Deliverable 1 summarizing Project Task 1: "Technology Review and Availability Assessment of Liquid Desiccant Systems " The main objective of this report was to identify liquid desiccant technologies which are suitable for the pilot installation, and select a preferred vendor to supply the liquid desiccant technology. SECTION 1 EXECUTIVE SUMMARY AND OVERALL FINDINGS SECTION 2 INTRODUCTORY REMARKS ABOUT DEHUMIDIFICATION TECHNOLOGIES SECTION 3 IMPORTANT ASPECTS OF LIQUID DESICCANT DEHUMIDIFICATION FOR HVAC APPLICATIONS SECTION 4 RECENT LIQUID DESSICANT DEVELOPMENTS AND IDENTIFIED FUTURE RESEARCH NEEDS This section discusses basic considerations of dehumidification technologies and their application in dehumidification for industrial and commercial processes. This section also describes why dehumidification is of increasing relevance in the building industry and why liquid desiccant dehumidification technology is an important solution to provide advanced humidity control in buildings. This section summarizes important processes of liquiddesiccant dehumidification technologies as they relate to HVAC applications in buildings. This section presents reviewed literature that discusses advances in liquid desiccant (LD) air dehumidification to make this new technology suitable for residential and commercial HVAC systems. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 27

34 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 SECTION 5 REVIEW LIQUID DESICCANT TECHNOLOGIES OFFERED BY DIFFERENT VENDORS SECTION 6 RANKING OF COMPANIES AND TECHNOLOGIES This section introduces several companies which are in the process of developing and have a track record of developing, manufacturing and/or selling liquid desiccant technologies. A literature research identified seven candidate companies, which have track records in desiccant dehumidification. This section present2 the methodology and results of ranking the liquid desiccant technologies and the vendors. This section also presented the vendor selected for the project. Main Conclusions: The report assesses and ranked the liquid desiccant technologies of six vendors using a two tiered ranking methodology (see Figure 2.2). The results of the ranking are presented in Figure 2.3. The East Coast company AIL Research Inc. received the highest score and was selected as the preferred vendor. No Criteria categories (1st level) Overall weight 1st level 2nd level Ranking criteria (2nd level) (1st * 2nd level) 1 Technology maturity 25% 1.1 Technology status is mature and tested in real world setting 40% 10% 1.2 Technology has passed the level of concept 30% 8% 1.3 Technology has manageable but exciting innovation potential 30% 8% sum 2nd level >>> 100% 25% Figure 2.2: Ranking of companies and technologies First tier overall weights 2 Prior installation /application experience of technology 20% 2.1 Products have been installed in Hawaii (tropical) climate 35% 7% 2.2 Technology has been tested in Hawaii (tropical) climate 25% 5% 2.3 Ability to use heat source specific to Hawaii (i.e. solar) 40% 8% sum 2nd level >>> 100% 20% 3 Technology flexibility / ability to implement pilot installation 40% 3.1 Flexibility do apply in smaller installations 25% 10% 3.2 Ability to deviate from standard & prefabricated (larger) systems 15% 6% 3.3 Ability to retrofit an existing HVAC 30% 12% 3.4 Ability to build / configure HNEI hybrid system 30% 12% sum 2nd level >>> 100% 40% 4 Communication / willingness to cooperate substantially 15% 4.1 Ease of communication 25% 4% 4.2 Willingness & ability to provide technical support for pilot install. 30% 5% 4.3 Ease to transport system to Hawaii 20% 3% 4.4 Ease to purchase domestic (US) products 25% 4% sum 2nd level >>> 100% 15% sum 1st level >>>>>> 100% Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 28

35 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Company Total score Rank No. 1 7 AC Technologies 62% 3 No. 2 AIL Research Inc. 96% 1 No. 3 Be Power Tech 37% 6 No. 4 Kathabar Dehumidification Systems, Inc 56% 5 No. 5 L dcs GmbH 90% 2 No. 6 Menerga Apparatebau, GmbH 60% 4 Figure 2.3: Total scores of ranking for six companies Figure 2.4: Total scores of ranking for six companies Based on the selection criteria and the assignment of how well the companies perform in accordance to the ranking statement, the two companies AILR and L DCS had the highest total scores. The advantages of AIL and L DCS include their flexibility to adapt their proven technology products to a narrow design envelope, and their willingness to cooperate in fitting their technology to a suitable test site for the pilot HVAC installation in Hawaii. AILR was finally selected because it is a US company which has had long track record of well performing demonstration projects and several commercial product sales, including an installation in Hawaii. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 29

36 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Deliverable 2 summarizing Project Task 2: "Identify Application Potential in Hawaii" The main objective of this report was to discuss the interactions of two goals of good space conditioning, (1) save energy in providing space conditioning, and (2) providing a good indoor environmental quality. The report pointed out that humans are spending up to 90% of their time indoors and thus creating a conducive indoor environment is an increasingly important requirement for buildings. This report discusses general concepts and develops a generic decision model to quantify the advantages of basic candidate system to provide good IEQ and save energy. SECTION 1 EXECUTIVE SUMMARY AND RECOMMENDATIONS SECTION 2 REVIEW OF INDOOR ENVIRONMENTAL QUALITY This section discusses the following emerging focus on indoor air quality: On average, people spend about 90% of their time indoors (NIBC, 2017). The issue of indoor environmental quality is becoming more important as buildings are more effectively sealed, thus effectively isolating indoor space from the climatic rhythm of the external natural environment. But as modern life increasingly centers around indoor activities, most people have adapted to the indoor realm as their "natural" environment. To satisfy the human need for affinity to the natural world, inside the built environment, natural conditions can be emulated, and these enhance health, productivity and the human experience. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 30

37 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 SECTION 3 PERFORMANCE: SPACE CONDITIONING TECHNOLOGIES FOR HAWAII SECTION 4 EVALUATING IEQ PERFORMANCE FOR SPACE CONDITIONING APPLICATIONS SECTION 5 INDOOR ENVIRONMENTAL REQUIREMENTS FOR SCHOOLS SECTION 6 PREPARING VISITS TO REPRESENTATIVE SITES SECTION 7 CONDUCTING VISITS TO REPRESENTATIVE SITES This section discusses generic performance of four basis space conditioning technologies used in Hawaii. There four technologies are as follows: (A) Natural ventilation, (B) Natural ventilation (with mechanically induced indoor air movement), (C) Mechanical ventilation, (D) Full, standard HVAC This section evaluates and ranked the performance of the four space conditioning technologies presented in Section 3 and compared them with the proposed LDAC technology, regarding Indoor Environmental Quality (IEQ) and energy saving potential. This section discusses specific application of the proposed LDAC technology unit for schools. Schools have a high requirement for high indoor environmental quality since children and young adults have a higher susceptibility to problems arising from unhealthy indoor conditions. This section provided a summary of basic requirements for a high quality learning environment. This section presents efforts which were taken by the project team to engage stakeholders of educational facilities that were considered candidate locations for the installation of a pilot liquid desiccant dehumidification unit for space conditioning. Several site visits were conducted to obtain information about different building aspects and space conditioning technologies, which are of importance to the proposed innovative hybrid space systems with liquid desiccant dehumidification. Main Conclusions Achieving good indoor environmental quality (IEQ) is an important concern in modern building design. Since humans spend about 90% of their time indoors, the indoor environment must provide healthy and productive conditions to avoid risks to the occupants. Figure 2.5 indicates important elements of the indoor environmental experience. The different IEQ elements were placed into three categories based on their impact on HVAC design. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 31

38 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 These three categories and the individual characteristics therein were assigned different weights for a ranking procedure of the four conventional space conditioning technologies PLUS the new proposed LDAC technology. The ranking assigned to the five space conditioning systems, four conventional technologies plus the LDAC, determined their performance levels when considering both IEQ and energy saving. Figure 2.6 shows the results of the ranking for the Systems A through E, which are defined as follows: Conventional space conditioning technologies NEW proposed system System (A) Natural ventilation System (B) Natural ventilation (with mechanically induced indoor air movement): System (C) Mechanical ventilation: System (D) Full, conventional HVAC: System (E) Proposed LDAC technology, decoupled liquid desiccant dehumidification with energy efficient sensible cooling Figure 2.5: Interrelationship of aspects of IEQ, IEQ aspects grouped into three categories with different ranking weights Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 32

39 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Figure 2.6 : Overall ranking scores of System A through E The overall score indicates the level of performance when both providing high energy savings and good IEQ are considered in a comprehensive assessment framework. With energy saving and IEQ being the two main parameters in the ranking methodology, a sensitivity analysis was performed that indicated how the five space conditioning systems A though E rank as the importance of energy saving and IEQ improvements were changed relative to each other. Figure 2.7 shows the ranking scores of Systems A through E with different importance of IEQ and energy savings. The results of the sensitivity analysis indicate that the proposed LDAC technology performs well over the entire range of varying importance of energy savings and IEQ. Overall ranking score [%] 100% 80% 60% 40% 20% 0% 0% 20% 40% 60% 80% 100% Low System B: Nat. Ventilation with internal fans System A: Only natural ventilation System D Full conventional HVAC Contribution in % of energy to overall ranking Importance of energy savings System E: Proposed hybrid system System C: Mechanical ventilation (ducted) High Figure 2.7 Relationship between the contribution of energy savings potential to overall ranking score High Importance of Indoor Environmental Quality Low Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 33

40 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Deliverable 3summarizing Project Task 3: "Identification of best system integration " "Assessment of Liquid Desiccant Dehumidification Systems and Supporting Thermal Technologies and Concept Designs with Emphasis on Application Potential in Hawaii " The main objective of this report was to identify the best system integration of decoupled dehumidification and sensible cooling technologies. The best integration was determined based on general application potential in Hawaii and for the specific pilot installation. EXECUTIVE SUMMARY AND RECOMMENDATIONS SECTION 1 BENEFITS OF DECOUPLING LATENT AND SENSIBLE HEAT REMOVAL SECTION 2 CHARACTERISTICS OF LIQUID DESICCANT BASED SPACE CONDITIONING SECTION 3 ASSUMPTIONS OF OUTDOOR AND INDOOR CONDITIONS FOR DESIGN CONCEPT ANALYSIS SECTION 4 ESTABLISHING THE ENERGY AND MASS BALANCE OF THE DESIGN CONCEPT LD SYSTEM This section discusses benefits of decoupling sensible and latent heat removal. Important basic processes and properties of the process of decoupling sensible and latent heat removal cooling and dehumidification are described. This section reiterates the process of liquid desiccant dehumidification, and pointed out the basic differences and advantages of desiccant dehumidification over standard cooling based dehumidification. This section describes basic outdoor and indoor environmental and thermal conditions that were used for the subsequent design concept analysis and illustrative case studies. This section presents a simplified basic energy and mass balance assessment for the design concept of the LDAC system. The design concept analysis provides the basic design data to determine feasibility and generic Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 34

41 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 performance of the peripheral sensible cooling and heating technologies. SECTION 5 SELECTING CANDIDATE PERIPHERAL COOLING AND HEATING TECHNOLOGY TO SUPPORT THE LD CORE SYSTEM SECTION 6 INTEGRATED LIQUID DESICCANT AND SENSIBLE COOLING TECHNOLOGIES CANDIDATE TECHNOLOGIES FOR SINGLE BUILDING SECTION 7 EVALUATING CANDIDATE PERIPHERAL TECHNOLOGIES AND RANKING OVERALL SYSTEM PERFORMANCE SECTION 8 RECOMMENDED SELECTION OF PERIPHERAL THERMAL TECHNOLOGIES AND TEST SYSTEMS This section describes the scope of the cooling and heating technologies that can be considered as peripheral technologies in support of the core liquid desiccant (LD) system. This section investigates the performance characteristics of various sensible cooling and heating technologies which serve as peripheral thermal systems in support of the LD core dehumidification system. This section describes 24 alternative combinations of LD core dehumidification system and different sensible cooling and heating peripheral systems. A quantitative assessment of their performance was determined by using a 2,400 sqft. sample classroom space. The performance was ranked, and a risk versus benefit analysis was performed to determine the best among the 24 alternatives investigated. This section describes the best three system configuration based on the performance analysis performed in Section 7. Main Conclusions: Figure 2 8 illustrates the overall process concept of the proposed hybrid LD based space conditioning system. The liquid desiccant (LD) dehumidification core LD system consists of an absorber (also conditioner) and a desorber (also regenerator). The core LD system requires peripheral sensible cooling and heating, as well as several other support functions. The components depicted in Figure 2 8 are: Sensible cooling heat sink: either an electrically driven conventional vapor compression (VP) chiller or a thermally driven adsorption chiller Sensible cooling space cooling technologies: different technologies to capture indoor sensible cooling loads and convey it to the heat sink. These technologies include fan coil unit (FCU), active chilled beams (ACB), passive chilled beams (PCB) and chilled ceiling (CC). In addition, Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 35

42 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 ceiling fans are considered which provide an additional perception of sensible cooling to occupants. Heating, for desiccant regeneration, including: Solar thermal systems, fuel based boilers and combined heat and power (CHP) are considered. Energy storage, in the form of hot water storage and storage of concentrated desiccant solution Energy recovery, in form of evaporative cooling using the dry discharge air and membrane based enthalpy recuperation. Figure 2.8: Work process of the integrated liquid desiccant (LD) dehumidification with supporting sensible support functions Sensible support functions are referred to in this report as peripheral thermal technologies Twenty four (24) system alternatives were defined and their performance was assessed. A performance assessment resulted in a ranking of alternatives based on risk versus benefit, as shown in Figure 2.9. Main parameters were significance, the value the alternative would offer to applications in Hawaii; and practicality, the feasibility of using the alternative for the pilot tests. Figure 2.10 illustrates the significance versus the practicality ranking matrix. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 36

43 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Core Category A System configuration peripheral thermal technologies supporting the LD core Using VC chiller Using adsorption chiller LD core system X X X X X X X X X X X X X X X X X X X X X X X X Peripheral thermal technologies Cooling heat sink: A 1 VP chiller water cooled X X X X X X X X X X X X A 2 Adsorption chiller water cooled X X X X X X X X X X X X Figure 2.9: Summary of pertinent results of the risk versus benefit assessment B C D E Cooling space cooling techno B 1 Fan coil unit (FCU) X X X X X X X X B 2 Active Chilled Beam (ACB) X X X X X X X X B 3 Passive Chilled beam (PCB) X X X X X X X X B 4 Chilled ceiling (CC) Sensible heating C 1 Solar system X X X X X X X X X X X X C 2 Boiler (conventional and biofuel) X X X X X X X X X X X X Energy storage: D 1 Hot water storage X X X X X X X X X X X X D 2 Concentrated desiccant store. X X X X X X X X X X X X Energy recovery and CF redits: E 1 WBT recovery X X X X X X X X X X X X E 2 Membrane ERV (NA) E 3 Ceiling fans (CF) X X X X X X X X X X X X Peripheral thermal technologies Cooling heat sink: A 1 A 1 A 1 A 2 A 2 A 2 A 2 Cooling space cooling techno B 2 B 3 B 3 B 1 B 2 B 3 B 3 Sensible heating C 1 C 1 C 2 C 1 C 1 C 1 C 2 Energy storage: D 1 D 1 D 2 D 1 D 1 D 1 D 2 Energy recovery and CF redits: E 1 E 1 E 1 E 1 E 1 E 1 E %/50% Importance of practicality equal to significance criteria % value rank rank points Practicality/Significance Ratio: 80%/20% Importance of practicality larger than significance criteria % va l ue rank rank points 20%/80% Importance of significance larger than practicality criteria % value rank rank points A 1 59% % % 5 0 A 2 54% % % 3 0 B 1 46% % % 6 0 B 2 48% % % 4 0 B 3 84% % % 2 0 C 1 66% % % 1 0 C 2 53% % % 7 0 D 1 17% % % 9 0 D 2 40% % % 8 0 E 1 N/A N/A N/A E 2 N/A N/A N/A E 3 N/A N/A N/A Figure 2.10: Results of the practicality versus significance assessment for technologies Table Note: The energy recovery technologies E 1 through E 3 are not included in ranking A 1 VP chiller water cooled A 2 Adsorption chiller water cooled B 1 Fan coil unit (FCU) B 2 Active Chilled Beam (ACB) B 3 Passive Chilled beam (PCB) C 1 Solar system C 2 Boiler (fuel) D 1 Hot water storage D 2 Concentrated desiccant store. E 1 WBT recovery E 2 Membrane ERV (NA) E 3 Ceiling fans Based on the performance of the 24 alternatives, three candidate configuration of LD core technology and peripheral cooling and heating technologies were selected for the pilot installation. Since the initial Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 37

44 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 test will be carried out in a lab controlled environment, which has unique characteristics that may differ from general application potential, a candidate system configurations emerged and was selected for the initial test in the lab. Figure 2.11 shows the basic diagram of the selected system configuration: Conditioned space (B) Space cooling technologies Passive chilled beam (PCB) Ceiling fan (CF) (A) Cooling heat sink: Conventional VC HVAC Sensible Cooling (E) Energy recovery WBT energy recovery Cooling tower Liquid Desiccant (LD) core (C) Heating technologies: Solar water heating (D) Energy storage: Hot water storage Figure 2.11: Proposed test system for the Test system A represents a conservative approach to testing, since it uses conventional VC chiller and on demand heat source (boiler). The energy storage is optional, though testing would add valuable data. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 38

45 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Deliverable 4 summarizing Project Task 4: "Design of Test Set up in Project Phase II" ""Design Study of a Packaged Liquid Desiccant (LD) System in a Test Facility to Carry out a Test Program under Lab Conditions and Subsequent On site Test Operation of the LD System " The main objective of this report was to present the preliminary design of a liquid desiccant air conditioning (LDAC) system which will be used for air dehumidification application tests in a lab controlled environment (Project Phase II/A). The basic premise of testing a liquid desiccant dehumidification system as part of an advanced HVAC system is to prove that the LD dehumidification technology will provide tangible benefits regarding energy savings and providing a high quality indoor environmental quality (IEQ). EXECUTIVE SUMMARY AND RECOMMENDATIONS SECTION 1 BENEFITS OF LDAC TECHNOLOGY FOR HAWAII SECTION 2 DESCRIPTION OF THE LDAC TECHNOLOGY USED FOR PILOT TESTS This section provides qualitative and quantitative assessments of the value proposition provided by the proposed LDAC system to Hawaii. The discussion presented in this section stresses the importance of considering both indoor environmental quality and energy savings when designing HVAC systems that comply with Hawaii s sustainability goals. High indoor environmental quality (IEQ) is an important underpinning for the more comprehensive indoor wellness and comfort conditions in high performance or green building. This section describes the liquid desiccant technology that will be used for the present project. While liquid desiccants have been used for specific drying and dehumidification applications for several decades, the use of liquid desiccants in generic HVAC systems is a Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 39

46 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 rather recent and still innovative technology. This section assesses the energy costs and the financial benefits for companies of increased IEQ conditions, realized through the proposed LDAC technology. SECTION 3 TESTING OF THE LDAC SYSTEM IN PROJECT PHASE II SECTION 4 TESTS OF PHASE II/A INITIAL SHAKE DOWN TESTS IN UHM MARINE CENTER SECTION 5 TESTS OF PHASE II/B PILOT INSTALLATION AT LOCATION TBD This section describes the two parts of Project Phase II, Part A and B, during which the performance pilot installation of an LDAC will be tested; first in a lab controlled environment (Phase A) and then in a regularly occupied space (Phase B). This section presents the preliminary design of the system installation for the initial system test in the labenvironment of the UHM Marine Center at Pier 35. This section describes objectives and plans for Project Phase II/B. During Phase II/B the LDAC unit will be installed at a test location, e.g. indoor space, whose size and space conditioning requirements will match the LDAC unit that was used and tested in Phase II/A. Main Conclusions: The performance of green buildings has been typically quantified by the scope of external environmental impact, and especially energy consumption. The emergence of wellness and healthy building standards have introduced a new form of primary internal performance metrics, where financial benefits of more healthy and productive buildings can be assessed. Especially in hot, humid Hawaii, savings both in terms of energy and healthy and productive buildings are valued and the projected LDAC system can realize both. This report quantifies the projected energy savings and IEQ and wellness financial benefits using an example 8,000 office space. Figure 2.12 compares the energy performance of a standard HVAC system and the proposed LDAC system, where the proposed LDAC system provides twice the ventilation air flow rate than the standard HVAC. Figure 2.12 indicates that the LDAC provides approximately a 30% savings relative to the standard HVAC. Figure 2.13 compares equivalent carbon emissions of the proposed LDAC system and a standard HVAC, both with vapor compression chillers the sensible heat sink. Here carbon emissions are reduced by about 40% with the LDAC system. Looking forward, when using thermal chillers as sensible heat sinks, the carbon equivalent savings increase to more than 80% relative to standard HVAC. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 40

47 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Figure 2.14 presents the combined savings of energy and IEQ and wellness related increases in employee productivity and reduction in health risk. Figure 2.14 exemplifies that the financial benefits derived from increased IEQ and wellness greatly surpass the financial benefits of energy savings with 96% of the savings derived from improved IEQ and 4% from energy savings. The report provides the design documentation of the preliminary design for the pilot test set up during Project Phase A. Figure 2.12: Comparison of energy performance Ths figure suggests that energy costs savings of about 30% can be anticipated under the assumed conditions. Carbon Dioxide Equivalent [% of baseline] 100% 80% 60% 40% 20% 58% 100% 17% Figure 2.13: Reductions in equivalanet carbon emissions. Percentage comparison of baseline carbon equivalent emission between three HVAC systems: 1. Proposed LDAC with vapor compression chiller 2. Standard HVAC 3. Proposed LDAC with thermally driven adsorption chiller 0% 1. Proposed LDAC system, with vapor comprestion chiller 2. Standard (baseline) AC 3. Most efficient LDAC system all solar Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 41

48 Project Summary Overview of Finding and Conclusion PART 2: OVERVIEW OF WORK SCOPE OF PROJECTS DELIVERABLES 1 THROUGH 4 Figure 2.13: Comparison of energy savings and increased revenues based on productivity gains through higher IEQ and wellness The image illustrates how potential revenue gains compare to the projected energy savings. The potential revenue gains are through increased productivity. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 42

49 Project Summary Overview of Finding and Conclusion PROJECT SUMMARY POWER POINT PRESENTATION PROJECT SUMMARY POWER POINT PRESENTATION The following is a power point presentation which summarizes the project work and the main conclusions and recommendations. Project Deliverable No. 5: Project Summary Sustainable Design & Consulting LLC November 27, 2017 Page 43

50 PROJECT SUMMARY PRESENTATION THE GROWING INDOOR HUMIDITY CHALLENGE OF BUILDINGS AND STRATEGIES TO SOLVE THEM Preparing a Pilot Installation in Hawaii of Using Liquide Desiccant Dehumidification in HVAC to Avoid Indoor Humidity Problems and Improve Indoor Air Quality while Saving Energy Manfred J. Zapka, PhD, PE ( 1) James Maskrey, MEP, MBA, Project Manager (2) (1) Sustainable Design & Consulting LLC, Honolulu, Hawaii (2), Honolulu, Hawaii Sustainable Design & Consulting LLC Hawaii Natural Energy Institute November 27, 2017

51 ACKNOWLEDGEMENTS This project is funded by the under grant no. N from the Office of Naval Research. The authors would like to thank both HNEI and ONR for the opportunity to pursue explore the potential for this technology. The authors believe that desiccant cooling applications can be a significant contribution increasing the energy efficiently of building conditioning, providing a better humidity control and foster the implementation of more environmentally friendly ways to provide better occupant indoor environmental quality. Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

52 Synopsis: The Risks of Green Building As buildings become more energy efficient and sealed from the outdoor environment, increased humidity and related problems become the next challenge of green buildings The Problem with standard HVAC Cannot effectively provide cool temperatures and accurately control humidity need to use different HVAC strategies and technologies for hot and humid climate of Hawaii The Solution Decoupling (separating) sensible from latent cooling loads, which is impossible for standard HVAC The Technology of choice Innovative low flow liquid desiccant HVAC systems LDAC The Benefits of LDAC to the Environment Significant energy savings and reduced carbon emissions The Benefits of LDAC to Occupants, Companies and Building Owners Significant financial benefits from improved Indoor Environmental Quality which saves health related costs and increases work productivity The Conclusion Hawaii needs new HVAC technologies like the proposed LDAC as we pursue meeting our important energy goals and creating more healthy and productive buildings at the same time. Pathways Install and test a pilot LDAC system in Hawaii, first in a lab controlled environment, and then in a regular conditioned space. Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

53 Energy efficiency and smart migration to renewables is essential for Hawaii. Credit: Howard Wiig, Energy Office of Hawaii Hawaii has made good progress in decreasing energy consumption Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

54 The Problem: While we are getting very good at saving energy in buildings we are not paying enough attention to humidity related problems. Article from 2009 Energy experts have been pointing to several problems of Green Buildings, one of which are humidity related problems. All of them are solvable with the right approach Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

55 Energy Codes are main drivers in achieving energy conservation.. Heat gain in building will continuously decrease as building envelopes improve, reducing energy use. Energy Usage Index (1975 use = 100%) 2017 Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

56 EXTERNAL AND INTERNAL SENSIBLE HEAT GAIN IN BUILDINGS We need to remove heat gain form indoor spaces to provide good thermal comfort the less heat the more energy efficient Space conditioning Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

57 Shading windows HOW WE CAN REDUCE HEAT GAIN: Shading of windows Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

58 High performance windows HOW WE CAN REDUCE HEAT GAIN: High performance windows Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

59 Wall insulation HOW WE CAN REDUCE HEAT GAIN: Add Wall insulation to decrease conduction gains Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

60 Sealing envelope HOW WE CAN REDUCE HEAT GAIN: Add effective envelope sealing to decrease infiltration Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

61 Cool roofs Insulating attics HOW WE CAN REDUCE HEAT GAIN: Add cool roof designs and insulating attics Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

62 Energy Star appliances and equipment Energy efficient lighting HOW WE CAN REDUCE HEAT GAIN: Energy efficient lighting and appliances / equipment Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

63 Super insulated house with small windows????? How far should we go to lower the energy use in buildings?? Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

64 QUALITY (IEQ) AND WELLNESS CUTTING ENERGY USE INDOOR ENVIRONMENTAL QUALITY (IEQ) AND WELLNESS are evolving as a important metrics for high performance buildings supplementing the prevailing metric ENERGY EFFICIENCY. Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

65 Fact: Creating healthy and productive indoor spaces, with high Indoor Environmental Quality, using conventional building technologies will increase energy consumption Increased ventilation Increased reheat Increased HVAC Increased glazing to provide views and daylight Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

66 Facts: New technologies and operational approaches are required to create BOTH energy efficient AND health and productive buildings. For Hawaii innovative HVAC technology can offer BOTH good thermal comfort and good indoor air quality in an energy efficient way. Humidity 800 pound Gorilla in the room.. for hot and humid climate in Hawaii Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

67 The ratio of sensible and latent loads are changing significantly Sensible or Latent Heat [BTU/h] Sensible Heat Ratio [SHR] Latent Heat Ratio [LHR] 0 Time scale (arbitray) Sensible Heat Latent Heat Time scale (arbitray) SHR LHR 0.2 As the sensible cooling decrees the latent load increases proportionally Creating challenges for standard HVAC Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

68 Mold..!! Low SHR cooling loads create problems with conventional HVAC technology as they cannot efficiently mitigate humidity related problems, especially in Hawaii s hot and humid climate. Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

69 Most Effective Approach to Solve the Growing Humidity Problem Decouple Cooling Loads Decouple sensible and latent cooling load LATENT COOLING SENSIBLE COOLING >>>> Standard HVAC operation with simultaneous sensible and latent cooling load removal Advanced HVAC which decouple sensible and latent load removals. >>>> Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

70 Conventional AC with cooling based dehumidification Cannot be decoupled Problem, cooling based dehumidification cannot be separated from sensible cooling Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

71 Typical problems with conventional AC overcooling and insufficient dehumidification Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

72 Health risk factors when controlling for indoor relative humidity (RH) Relative Humidity Organisms Bacteria Viruses Fungi Mites Allergic Rhinitis & Asthma Respiratory Infections Optimum level of RH Chemical Interactions Ozone production Levels of activity of harmful organisms and chemical interactions are directly affected by indoor RH level The value of 45% RH has been mentioned in the literature as optimum indoor RH Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

73 Ongoing HNEI Research Work in Advanced HVAC Present research work at the UHM (HNEI) to use liquid desiccants for dedicated humidity control Utilizes energy efficient hydronic sensible cooling technologies such as chilled beams and radiant cooling without condensation problems. Liquid desiccant technology has been used for many decades but not for conventional HVAC systems. Innovative Low flow desiccant technology is a recent development and is suitable for regular HVAC applications, it is a rapidly evolving technology. Building on previous technology development sponsored by NREL Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

74 Basic processes of liquid desiccant dehumidification Three main process steps in desiccant dehumidification Sorption process, water vapor migrates from the humid air to the desiccant. Water vapor pressure is higher in the moist air Desorption process humidity migrates from the desiccant to the hot scavenging air. Water vapor pressure is higher at the desiccant surface Different from standard cooling based dehumidification, liquid desiccant dehumidification does NOT require cooling air to drop below dew point. Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

75 Conventional liquid desiccant dehumidification processes Example of a packed columns liquid desiccant system For several decades Proven and effective dehumidification technology for specialized industrial and commercial applications It works well but has not been widely used in general HVAC applications Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

76 Innovative Low Flow liquid desiccant dehumidification processes developed for energy efficient use in HVAC Several Commercial installations AILR low flow" LD dehumidifier with three main components: conditioner, regenerator and interchange heat exchanger (IHX) The AILR patented absorber and regenerators design. Cooling tube are imbedded into an evaporative medium New Low flow liquid desiccant technology developed by AIL Research Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

77 Liquid Desiccant Air Conditioning (LDAC) systems need decoupled sensible cooling technology Chilled (radiant) ceiling Fan coil unit Active chilled beam Passive chilled beam Options for energy efficient sensible cooling technologies Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

78 New LDAC Technology to be tested in Hawaii Decoupled sensible & latent cooling Sensible heat removal = Cooling Latent heat removal = Dehumidification Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

79 Best LDAC technology for Hawaii Using solar energy to achieve the largest energy savings and lowest carbon emissions Sensible heat removal = Cooling Latent heat removal = Dehumidification LDAC system Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

80 Psychrometric performance of LDAC and standard HVAC The standard HVAC requires 64.8 tons ( tons) along PATH 1. The LDAC requires 43.2 tons along PATH 2; this is a saving of 33% Energy savings of the LDAC system $40,000 Energy Costs / Savings $30,000 $20,000 $10,000 $30,000 $9,000 $21,000 $0 Conventional DX HVAC system; min. ventilation rate Energy costs Proposed LDAC system; double min. ventilation rates Energy savings Comparison of annual energy costs between a standard HVAC and the proposed LDAC system. The energy calculation was done for a sample 8,000 sqft office. Predicted energy savings of several AILR liquid desiccant systems reported by NREL Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

81 Photo credit: japantimes.jp Lower carbon emissions from LDAC system compared to standard HVAC >>>>>>>>>> All solar LDAC achieves very high energy savings and carbon emissions reductions. Carbon Dioxide Equivalent [% of baseline] 100% 80% 60% 40% 20% 0% 58% 1. Proposed LDAC system, with vapor comprestion chiller 100% 2. Standard (baseline) AC 17% 3. Most efficient LDAC system all solar Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

82 Pilot Project in Hawaii using two basic (and decoupled) HVAC technologies: AILR LDAC unit for precise dehumidification Passive chilled beam for energy efficient sensible cooling Test program in two Phases: First Phase, testing of LDAC in a lab controlled environment Second Phase, testing of LDAC in a regular, but demanding, HVAC application Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

83 Advantages of LDAC over standard HVAC Separates (decouples) control of cooling and dehumidification Achieves significant energy savings Avoids overcooling and reheat of supply air Can use renewables for desiccant regeneration Mitigates humidity problems Allows for increased fresh air ventilation Offers improved Indoor Air Quality Increase Indoor Environmental Quality and Wellness Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

84 Tangible financial benefits through IEQ and Wellness Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017

85 Harvard Healthy Building Program estimates ~ $6,500 per employees from increased productivity through increased ventilation and better indoor environmental quality. Project Summary Presentation by Manfred J. Zapka and James Maskrey, November 2017