1/2011. Das TGA-Online Portal. Organ des Organ des. adwkuihdfwu. Assessment

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1 / Das TGA-Online Portal Organ des Organ des Reprint Titelthema Graphite-modified glächenkühlung Cooling mit Ceilings A sdsuui Comparative Asiasujhdoiudw Performance Assessment adwkuihdfwu

2 Reprint» from tab / Graphite-modified Cooling Ceilings A Comparative Performance Assessment The use of graphite-modified building materials increases in most cases their thermal conductivity. In chilled ceiling systems a considerably greater heat absorption is thus achieved than by conventional chilled ceiling systems. The resulting benefits are identified. For this purpose simulations are carried out both for the determination of thermal comfort and also for quantifying the effects on the electricity demand for cooling. It becomes apparent that the higher cooling capacity of the graphite-modified cooling ceiling ECOPHIT has a positive effect on the operation. Prof. Dr.-Ing. Gerd Hauser, Prof. Dr.-Ing. Dr. h.c. Gerhard Hausladen, Dipl.-Ing. (FH) Cornelia Jacobsen, Dipl.-Ing. Christina Hutter, Dipl.-Ing. Christoph Hanusch, Dipl.-Ing. Stephan Schlitzberger Full professor of the Technical University of Munich and director of the Fraunhofer Institute for Building Physics Stuttgart Full professor of the Technical University of Munich and owner of the engineering office Hausladen GmbH in Munich Member of the extended board and director of the energy department of the engineering office Hausladen GmbH in Munich Member of the staff of the engineering office Hausladen GmbH in Munich Member of the staff of the engi ne ering office for building physics CD profiles Schematic section Copper tube G raphite is a material with superior thermal conductivity which is used in many products. So, SGL Carbon GmbH has developed a procedure to produce graphite panels with a thermal conductivity value which can exceed that of aluminum on the plane level and can have at the same time the conductivity of clay render perpendicular to the panel surface. The heat is thus distributed very quickly and evenly. It was logical therefore to use these panels which are distributed under the name ECO- PHIT, for cooling ceilings. The objective of the study presented below is the comparison of the ECOPHIT cooling ceiling with a conventional cooling ceiling. Graphite lightweight panel Description of the ECO- PHIT - and the reference cooling ceiling In summer cooling ceilings absorb the heat at the ceiling Graphite-modified plasterboard which is then discharged through water-flow pipes. The cooling capacity is the higher the better the heat transfer from the surface to the pipes is. In conventional systems, heat conductor sheets are used. In the ECOPHIT cooling ceiling, the graphite does this job. a) ECOPHIT cooling ceiling The focus of the study is on a gypsum chilled ceiling without joints. Room side enclosed with a graphite-modified plasterboard. Above this is a lightweight building board with integrated copper tubes. Figure shows a schematic cross-section of the ECOPHIT cooling ceiling examined. A test report on the determination of the cooling capacity of the chilled ceiling is available in accordance with DIN EN []. The subject of the investigation consists of: The graphite lightweight board ECOPHIT L from SGL Carbon GmbH which is made of expanded natural graphite and serves as cooling element. This has a thermal conductivity of. W/(mK) (horizontally) and. W/(mK) (vertically). In the graphite plate, two parallel tubes are centrally installed (outside diameter mm). The axial distance between the copper tubes amounts to mm. The distance between the tubes and the surface of the graphite lightweight panel amounts to approx. mm. The cooling elements rest on the unperforated, graphitemodified plasterboard panel Rigips Climafit (thickness mm). Thanks to the graphite granules which it contains, the panel achieves horizontally and vertically a relatively high thermal conductivity of. W/(mK). The cooling elements are pressed onto the plasterboard panels by metal framing components of the ceiling substructure lying above them. System profile of ECOPHIT cooling ceiling Schematic section Sub-structure Copper tube Heat conducting profile System profile of Thermal plate (plasterboard) b) Reference cooling ceiling A cooling ceiling with thermo plate and heat conductor sheets is considered as the. The structure is shown schematically in figure. The cooling ceiling consists of heat conducting plates with pressed-in copper tubes attached loosely to the even plasterboard panel and located with support rails. A test report in accordance with DIN EN is on hand. The constituent parts of the refe r ence cooling ceiling are described below: These heat conducting plates are composed of extruded aluminum profiles into which copper tubes are pressed (outside diameter mm). The axial distance between the copper tubes amounts to mm. The heat conduction profiles are loosely located with support rails on a mm, even plasterboard panel ( thermal plate of the Knauf Company). Due to the comparatively high gross density, the thermal conductivity of this plasterboard panel, at. W/(mK) lies above that of conventional plasterboard panels.

3 from tab / «Reprint Temperature and capacity profiles of the ECOPHIT system during one week in summer Temperature [ C] External air temperature Air temperature Operative temperature Cooling ceiling temperature Flow temperature Return temperature Global radiation Cooling efficiency Mass flow Efficiency [W/m²]/ Mass flow [kg/h] The plasterboard panels are screwed between the elements onto rails which are secured to the ceiling. The relevant technical data for the investigation of the ECOPHIT- and the Table : Simulation boundary conditions Boundary conditions Office Conference Usage. a.m. 6. p.m. Number of persons Sensible heat emission per person W W. a.m.. p.m. Aid 6 W W Illumination W/m² W/m² Target light intensity lux lux Daylight factor % % Infiltration. h -. h - Hygienic air change m³/(m²h) m³/(m²h) Table : Cooling ceilings Technical data Technical data of the cooling ceiling ECOPHIT system Reference system DIN EN DIN - DIN EN Nominal refrigeration [W/m²] DIN - Active surface [m²] Designing mass flow [kg/(m²h)] Tube distance [cm].. Tube inner diameter [mm].. Horizontal heat transfer coefficient U wrx [W/(m²K)]..9 are summarized in Table. Thermal simulation a) Approach, boundary conditions The temperature profiles and energy demand values are determined dynamically by means of thermal simulation. For this purpose the data of three representative rooms of an office building have been fed in: open-plan office west, open-plan office east and conference room west. These prestigious rooms represent a typical office building. For the weather boundary conditions the data of the current reference year [] is used. The north-east German lowlands serve as climatic region with the representative station Potsdam. Both are under consideration: the average year and the test reference year with an extremely hot summer. The three rooms investigated are identical as regards their geometry. The floor area amounts to m² with a clear room height of. m, this gives a room volume of. m³. The solid external wall is massive with external thermal insulation (U =. W/(m²K)), the interior walls are executed in light dry construction mode. The floors have a plastic coat, cement floor screed and impact sound insulation. The window area amounts to.6 m², which corresponds to a window surfacearea percentage of %. The windows are double-glazed with thermal insulation glass (U w =. W/(m²K), g =.6) with % frame. In addition, an external sun protection (F C =

4 Reprint» from tab / Operative room temperature 6 >6 C > C > C >9 C > C Operative room temperature >6 C > C > C >9 C > C Office west Office east Conference west Office west Office east Conference west Office west Office east Conference west Extreme summer, mechanical ventilation, Office west Office east Conference west Extreme summer, mechanical ventilation, in buildings with natural ventilation in buildings with mechanical ventilation.) is taken into account, which closes automatically when the total radiation (sum of direct and diffuse radiation) rises to more than W/m². It is assumed that even if the sun protection is closed, sufficient natural daylight gets into the room so that no artificial light is needed. The internal heat loads as well as the infiltration due to leakages and the required hygienic minimum air change (via natural or mechanical ventilation) are applied in accordance with DIN V 99- [] resp. DIN - [] (see Table ). Additional natural ventilation for the dissipation of the thermal heat loads or night ventilation is not carried out. The variant with mechanical ventilation is used only during operation times to obtain comparable results. The supply air temperature amounts to C consistently, in addition the supply air is dehumidified to a maximum absolute humidity of g/kg. The ideal heating of a room is considered to be C with % radiant share (panel radiator) which can be activated when the outside temperature is lower than C on the h average. b) Input data cooling ceilings The performance data of a chilled ceiling can be determined in various ways and on the basis of different standard specifications. DIN - [] has been withdrawn and replaced by DIN EN. For both chilled ceilings examined, test reports according to DIN EN are, therefore, available. As, however, technical data according to DIN - are required for the simulation software TRNSYS., conversion under consideration of the differing area and temperature references of the two standard specifications (see Table ) was carried out. Moreover, the equations of Koschenz [6] which apply to thermal active building elements are applied analogously in order to calculate the heat transfer coefficients from water into the horizontal panel planes U WRX. The chilled ceilings are designed with a coverage rate of % (initial case) or 6 % (reduced size). This coverage rate describes the ratio of the plate surface to the total ceiling area of the room. Thus with the rooms examined having a floor area of m², the size of the chilled ceiling in the initial case is. m² (active area according to DIN -) and 6. m² in the variant with reduced size. In the initial case the flow temperature is maintained at 6 C but at least K above dew point temperature in the room (dew point monitor). Whenever full power is not needed, the mass flow is reduced (automatic control via P-regulator). c) Simulation variants The following parameters are simulated individually or in combination with each other: Type of room (office west, office east, conference west) Type of chilled ceiling (reference system, ECOPHIT system) Test reference year (average year, extremely hot summer) Ventilation (natural ventilation, mechanical ventilation) Size of the ECOPHIT cooling ceiling ( % coverage, 6 % coverage) Flow temperature of the ECOPHIT cooling ceiling (6 C,. C) This study shows only a selection of the variants investigated. Simulation results The aim of the simulation was to determine the annual course of the cooling energy demand in all variations. For the evaluation of the thermal comfort the operative temperature (room temperature) 6 Operative room temperature >6 C > C > C >9 C > C 6 9 Flow temperature. C for an increased supply temperature of the ECOPHIT system

5 from tab / «Reprint Dew-point monitor frequency Flow temperature during hours of operation is, in addition, determined. At air velocities of up to. m/s it is composed of equal halves of the air temperature and the radiation temperature of the surrounding surfaces. Hereby a temperature is indicated which comes closer to the temperature actually felt rather than the mere air temperature. Figure shows by way of example the simulation results of the version west office with natural ventilation and one week in summer with extreme summer temperatures. It illustrates that due to radiation cooling and natural ventilation at high outdoor temperatures the indoor temperature (red) rises above the operational temperature (green). It is shown, furthermore, that the performance of the cooling ceiling is not sufficient to keep the room temperature below 6 C at any time. Flow temperature (purple) must be increased to above 6 C on three days in order to prevent the temperature at the cooling ceiling falling below the dew-point temperature (dew-point monitor). The specific cooling performance (brown) refers to the cooling ceiling surface. Due to the temporarily reduced mass flow and due to deviating boundary conditions compared to the test room situation, this may be lower or higher than the nominal cooling capacity. In order to be able to make a statement about the frequency and heights to which the room temperatures are exceeded, the excess temperature hours are evaluated. As shown in figure and figure they are lower with the ECOPHIT system due to its higher cooling performance than with the reference system. This means greater thermal comfort in the rooms with ECOPHIT cooling ceiling under otherwise identical boundary conditions. For the variants with mechanical ventilation, supply air is in duced at a constant temperature of C. Thus excess tempe ra tures are reduced considerably compared to the variants venti lated naturally. Additionally it is investigated how far the flow temperature can be raised in the case of the ECOPHIT system to achieve a thermal comfort corresponding to that of the reference system. Here an iterative procedure is employed: the flow temperature is raised in the case of those variants with the ECOPHIT system until the excess-temperature hours are nearly identical to those of the respective variants of the reference system with a flow temperature of 6 C. The result is a flow temperature for the ECOPHIT system of. C as shown exemplary in figure 6. 9 Operative room temperature >6 C > C > C >9 C > C 6 for a reduced coverage size of the ECOPHIT system 6 6 Reduced size 6 Increased flow temperature Extreme summer, mechanical ventilation, Due to the higher flow temperature, an increased cooling efficiency can be achieved (see Energy efficiency results ). Besides benefits in terms of energy, an increased flow temperature also means that the dew-point monitor is less frequently required. The dew-point monitor is employed to avoid temperatures at the cooling ceiling falling below the dew-point tempera ture by increasing the flow temperature via a mixing valve room by room or in each control loop. If the design temperature lies close to 6 C, it has to be raised more often than when it is at. C. The frequency of activating the dew-point monitor strongly depends on the individual boundary conditions, e.g. infiltration, supply-air humidity and Designing flow temperature 9 internal moisture loads. In the case of the boundary conditions as determined for this simulation, the dew-point monitor is very rarely activated (see figure ) when using the ECOPHIT system with a design temperature of. C and mechanical ventilation. This could also be achieved with the reference system only if the indoor air humidity were substantially lower. This could be effected by reducing the humidity of the supply air, which would involve higher energy needs for the dehumidification. As shown in figure, the dewpoint monitor is also required for the building with natural ventilation and ECOPHIT system as no dehumidification takes place. In the west office with the reference system it is necessary 9 Extreme summer, mechanical ventilation, Flow temperature. C Dew-point monitor frequency for an increased design supply temperature of the ECOPHIT system Dew-point monitor frequency 9 Flow temperature during hours of operation of the cooling ceiling Increased flow temperature Designing flow temperature Flow temperature. C Dew-point monitor frequency for an increased design supply temperature of the ECOPHIT system

6 Reprint» from tab / EER EER % Partial load % Partial load 6 % Partial load % Partial load % Partial load % Partial load % Partial load 6 % Partial load % Partial load % Partial load EER [-] EER [-] - Outside temperature [ C] - Outside temperature [ C] EER in dependence on the outside temperature and the partial load for a chilled water output temperature of C EER in dependence on the outside temperature and the partial load for a chilled water outlet temperature of. C to raise the flow temperature up to % of the time when the cooling ceiling is in operation. With the ECOPHIT system, this is the case during only 9 % of the operating times. Moreover, it has been iteratively determined that the coverage of the ECOPHIT system can be reduced from % to 6 % in order to obtain an approximately identical thermal comfort to that achieved by the reference system (see figure 9). The reduced cooling ceiling surface area can result in a reduction of the investment cost. Furthermore, the degree of flexibility for the design of the ceiling increases, offering more space for the integration of lights or other installations. Cooling generation and energy efficiency a) Methodical approach and boundary conditions As the thermal simulations have shown, with an ECOPHIT cooling ceiling at a flow temperature of. C a thermal comfort can be achieved equal to the reference cooling ceiling at 6 C. The efficiency of cooling rises due to the increased flow temperature. The goal is to calculate the resulting energy saving. A precondition for an increased energy efficiency of the refrigeration unit is that it is actually configured according to the flow temperature of the cooling ceiling. Should the refrigeration unit produce only a low temperature level and the flow temperature for the cooling ceiling only be increasingly mixed, no energy saving for cooling would be achieved. That means also that in cases where other consumers exist which need a lower temperature level (e.g. RLT with dehumidification of supply air), these must be supplied with another refrigeration unit. A compact compression chiller serves as a basis of this investigation because it is a frequently used and cost-effective standard system. In a compression chiller a cooling medium passes through different physical states in a closed circuit: compression in the compressor, condensation in the condenser through heat transfer to a water, air or evaporation re-cooling system, decompression at the expansion valve and vaporization via a heat exchanger thereby generating cold water for building cooling. The energy efficiency can be described by the performance factor EER (Energy Efficiency Ratio) of a compression chiller. The EER complies with the ratio of the cooling capacity (benefit) and the electrical performance of the compression chiller (expenditure). Typical values for the EER depend on the compressor type, the cooling medium and the chilled-water output temperature as stated in DIN V 99-:- []. In the case of air-cooled refrigeration units, these values include not only compressor and pumps but also electrical auxiliary energy of fans for re-cooling. In the course of the year the efficiency of cooling changes dependent on the outside temperature and on the partial load factor. For the year as a whole it is also referred to as the SEER (Seasonal Energy Efficiency Ratio). This is the ratio between cooling generation and the annual energy demand for cooling. Cooling and electricity requirement refrigeration [kwh/m²a] Cooling requirement in a room (without RLT) Electricity requirement refrigeration cooling ceiling Ref. 6 C VL Eco. 6 C VL Eco.. C VL Ref. 6 C VL Eco. 6 C VL Eco.. C VL Normal summer, natural ventilation Extreme summer, natural ventilation for the natural ventilation scenarios Cooling and electricity requirement refrigeration [kwh/m²a] Specific cooling and electricity demand Specific cooling and electricity demand Cooling requirement in a room (without RLT) Electricity requirement refrigeration cooling ceiling Ref. 6 C VL Eco. 6 C VL Eco.. C VL Ref. 6 C VL Eco. 6 C VL Eco.. C VL Normal summer, mechanical ventilation Extreme summer, mechanical ventilation for the mechanical ventilation scenarios

7 from tab / «Reprint Distribution of cooling supply The SEER considers both, the real performance of the refrigeration unit under part-load conditions and also variable outdoor air temperatures. For this study it is assumed that it is possible to operate the refrigeration unit in a free cooling mode. When the outdoor temperature falls below the flow temperature, the building cooling water can here be cooled directly via a re-cooling system. Since cooling is done without a compressor, in the free cooling mode, energy is needed only for fans of re-cooling systems and pumps, so the energy demand is lower. The results of the thermal simulation are projected on a fictive office building with approx. m² floor space. It is understood that the office building is composed as follows: % west oriented offices, % west oriented conference rooms, % east oriented offices. In this way a balanced load profile corresponding to the real conditions can be represented. A calculation tool was developed on the basis of which the calculation of the efficiency of refrigeration is possible on an hourly basis. The tool is based on the calculation rules of DIN V 99-. Additional own calculation algorithms are developed in the free cooling mode. The tool calculates the EER hourly depending on the operating mode. Provided that an energy need for cooling exists the operating mode is determined in dependence of the outside temperature, flow temperature and return temperature. Possible operation modes are mechanical cooling (MC), free cooling mode (FC) or mixed mode (MC/FC). The investigation is based on the technical data of an airconditioned compact chiller with free cooling mode and a nominal cooling performance of kw. A scroll is used as compressor. The refrigerant is RC. Between the compact compression chiller installed outdoors and the pipe system of the building, a heat-exchanger with a temperature difference of K is interconnected. This means the refrigeration unit has to produce a chilled water output temperature K lower than the flow temperature of the building cooling water. Table shows the EER for various design temperatures of the refrigeration unit chosen. Additionally indicated is the cold water flow temperature in the building. In DIN V 99-, the EER standard values for 6 up to C are indicated. These values are extrapolated in the tool. Figure and figure illustrate the Energy Efficiency Ratios (EER) resulting from the calculation tool under the selected boundary conditions dependent on the partial load ratio and the outside temperature. The chilled water output and supply temperatures have been chosen according to the simulation flow and return-flow temperatures and in consideration of the temperature difference of the heat exchanger. It can be seen here that the EER drops with rising outside temperature. In comparison to an outlet temperature of C of cold water, the curves indicating an outlet temperature of cold water with. C result in a slightly higher EER at the same out side temperatures (compare also table ), EER under design conditions). A free cooling mode is also possible at higher outside temperatures. The efficiency of the refrigeration unit in the free cooling mode generally decreases with falling part-load ratio. In the mixed mode and low part-load operation, the efficiency may also drop below the efficiency of the cooling machine. For mechanical cooling the part-load ratio plays a minor role. For the calculation tool it is assumed that the compact compression chiller is operated only up to a minimum part-load of %. When the Fragmentation refrigeration [kwh/m²a] Free cooling mode Mechanical cooling with chiller MC Ref. 6 C VL Eco. 6 C VL Eco.. C VL Ref. 6 C VL Eco. 6 C VL Eco.. C VL Normal summer, natural ventilation Extreme summer, natural ventilation part-load drops below this range, cooling is effected via a buffer storage unit. b) Energy efficiency results With the aid of a specially developed calculation tool the energy need for the hourly simulation results can be determined. The evaluation is carried out for each of the variants, reference and ECOPHIT system with a flow temperature of 6 C and for the ECOPHIT system even with between free cooling and chillers, for natural ventilation Fragmentation refrigeration [kwh/m²a] Distribution of cooling supply Free cooling mode Mechanical cooling with chiller MC..9 Ref. 6 C VL Eco. 6 C VL Eco.. C VL Ref. 6 C VL Eco. 6 C VL Eco.. C VL Normal summer, mechanical ventilation Extreme summer, mechanical ventilation between free cooling and chillers, for mechanical ventilation 6.. a flow temperature of. C. Furthermore, the variants are investigated for the average summer and extreme summer conditions as well for natural ventilation and mechanical ventilation. The results for the cooling and electricity need are shown in figure and figure referring to the useful floor space of the building. The annual specific cooling requirement arising from the simulation is in the reference Table : EER (design conditions) as a function of the chilled-water output temperature Cold water outlet temperature Cold water flow temperature 6 C 6 C (no heat exchanger) C C (no heat exchanger) EER (designing case). (standard). (standard) C 6 C (tool). C. C.6 (tool) 6

8 Reprint» from tab / 6 Energy efficiency Energy efficiency Energy Efficiency Ratio [-] 6 EER (Energy Efficiency Ratio - designing) SEER (Seasonal Energy Efficiency Ratio) Energy Efficiency Ratio [-] 6 EER (Energy Efficiency Ratio - Designing) SEER (Seasonal Energy Efficiency Ratio) Ref, 6 C VL Eco, 6 C VL Eco,. C VL Ref. 6 C VL Eco, 6 C VL Eco,. C VL Normal summer, natural ventilation Extreme summer, natural ventilation Ref, 6 C VL Eco, 6 C VL Eco,. C VL Ref. 6 C VL Eco, 6 C VL Eco,. C VL Normal summer, mechanical ventilation Extreme summer, mechanical ventilation of the chiller in a building with natural ventilation of the chiller in a building with mechanical ventilation variant in a normal summer and with natural ventilation at 6. kwh/(m²a), the electri c ity demand for cooling is. kwh/(m²a). Because of the high cooling capacity of the ECOPHIT cooling ceiling, it can meet increased cooling requirements. Therefore the demand for cooling and electricity of the ECOPHIT variant is somewhat higher at 6. kwh/(m²a) for cooling and.9 kwh/(m²a) for electricity. As the ECOPHIT variant (. C flow temperature) is defined so that it provides the same level of comfort as the reference variant the cool ing requirement is also nearly the same. The electricity need for refrigeration drops to.6 kwh/(m²a). This consequently confirms the expectation that the efficiency of refrigeration generation can be increased by means of a higher flow temperature. This is also shown in the variant for the extreme summer when the cooling requirement is generally higher. With the ECOPHIT variant (. C flow temperature) the electricity need is reduced by 6 % through the increased efficiency of the refrigeration unit. In the variants with mechanical ventilation (figure ) attention should be paid to the fact that energy need for cooling considers only cooling in the room (i.e. cooling via the cooling ceiling). The energy need for supply-air in the AC system is not included. For the variant with mechanical ventilation and average summer, the specific cooling requirements and thus the specific energy need for cooling considerably exceeds the variant with natural ventilation. This is due to the fact that supply air is always supplied at C and as a result the cooling potential of the external air is dispensed with. Due to the increased efficiency of the refrigeration unit, the electrical energy demand can be reduced by up to % (average summer) resp. % (extreme summer) in the building with mechanical ventilation. The diagrams in figure and figure indicate the distribution of cooling in the free cooling mode and refrigerant machine operation. The sum of both bars complies respectively with the cooling requirement. The variants with mechanical ventilation require cooling even at lower outdoor temperatures, thus a significantly higher share of free cooling can be achieved. The share of free cooling can be increased with the ECOPHIT variants through increased flow temperature: by comparison with the reference variant, the share of free cooling rises with natural ventilation from % up to % (average summer) or from % to % (extreme summer), with mechanical ventilation even from % up to % (average summer) or from % up to % (extreme summer). In addition, the diagrams in figure 6 and figure illustrate the energy efficiency of the variants examined. The EER under design conditions (see also table ) as well as the SEER (annual cooling performance ratio) considering also the corresponding outside temperatures are both specified. Corresponding to the reduction in electrical energy demand, the efficiency increase through increased flow temperature lies between 6 % and %. Conclusion The study has shown that the enhanced performance of the ECO- PHIT cooling ceiling provides the following advantages: With the ECOPHIT system a higher thermal comfort in summer can be achieved than with the reference system even in the case of equal coverage of the ceiling ( %). Even in the case of a 6 % coverage of the ceiling with ECO- PHIT, the same thermal comfort can be achieved as with the with % coverage. With ECOPHIT the flow temperature can be increased from 6 C to. C compared to the reference with the same size of cooling ceiling to achieve the same thermal comfort in summer. A higher flow temperature increases the efficiency of the refrigeration unit by 6 % in the case of a naturally ventilated building and by to % in case of a mechanically ventilated building. Moreover, the frequency of the use of a dew-point monitor decreases. References [] DIN EN :-: Lüftung von Gebäuden Kühldecken Prüfung und Bewertung [] Bundesinstitut für Bau-, Stadt- und Raumforschung: Aktualisierte und erweitere Testreferenzjahre (TRY) von Deutschland für mittlere und extreme Witterungsverhältnisse. Zugriff. Juni, bbsr.bund.de/cln_/nn_6/bbsr/de/fp/zb/auftragsforschung/ EnergieKlimaBauen//Testreferenzjahre/ ergebnisse.html [] DIN V 99-:-: Energetische Bewertung von Gebäuden Berechnung des Nutz-, End- und Primärenergiebedarfs für Heizung, Kühlung, Lüftung, Trinkwarmwasser und Beleuchtung; Teil : Nutzungsrandbedingungen, Klimadaten [] DIN -:-: Wärmeschutz und Energie-Einsparung in Gebäuden; Teil : Mindestanforderungen an den Wärmeschutz [] DIN -:99-: Raumkühlflächen; Teil : Leistungsmessung bei freier Strömung, Prüfregeln [6] Koschenz, M., Lehmann, B: Thermoaktive Bauteilsysteme tabs, EMPA, Dübendorf [] DIN V 99-:-: Energetische Bewertung von Gebäuden Berechnung des Nutz-, End,-und Primärenergiebedarfs für Heizung, Kühlung, Lüftung, Trinkwarmwasser und Beleuchtung; Teil : Endenergiebedarf von Raumlufttechnik- und Klimakältesystemen für den Nichtwohnungsbau