Multifamily Program Gas Water Heaters: Sealed Combustion Crossover Products Abstract The purpose of this paper is to document the benefits of using crossover gas water heating products that combine the benefits of instantaneous and storage units for use in the Investor Owned Utilities Multifamily Upgrade Program (MUP), California Multi-Family New Homes (CMFNH) or the California Tax Credit Allocation Committee (CTCAC) program. This paper uses the HTP RGH-75F Condensing Sealed Combustion 20 gal water heater to demonstrate the benefits of the crossover configuration which yields substantial performance improvement and energy savings. Acceptance of these units into the multifamily programs will encourage the use of ultra-low NOx certified tank type water heating units with significantly improved efficiency, reduced energy cost, reduced greenhouse gas emissions, reduced utility space requirements, and the elimination of combustion appliance safety testing for water heating. At this time there are no sealed combustion water heaters available to California multifamily housing builders with an energy factor (EF) rating. The acceptance of these 20 gallons units, with an energy factor rating of.83, where 40 or 50 gallon units are typically required will allow the specification of higher performing modulating condensing sealed combustion units for use in multifamily housing projects for domestic hot water, including hot water and space heating combinations. These units provide a higher First Hour Rating, lower energy use, reduced devoted space requirements and the safety of sealed combustion. This paper demonstrates the project energy savings available with crossover units using two completed multifamily projects as examples. The savings are calculated under the projected scenario where the RGH- 75F is approved for the MUP program and specified for use on these projects rather than the actual lower efficiency units installed. The enhanced performance of these units would benefit residents, multi-family housing operators and project developers through better indoor air quality, lower capital and operating expenses, and reduced construction testing requirements. Description of need The renovation of multifamily projects presents the opportunity to reduce energy cost, reduce greenhouse gas emissions and enhance life safety. However, the currently approved units for supplying hot water for occupant use and space heating all have an Energy Factor (EF) less than.71 for the capacities of 75kbtu or less. A standard tank type unit specified for the MUP is limited to an EF equal to 0.71 or less. Instantaneous water heaters have higher Energy Factors but are typically not viable for these projects as they require supply lines greater than existing.5 diameter gas lines. Replacing the lines is typically impractical and cost prohibitive for these applications. Additionally, some areas of California have very hard water where instantaneous gas water heaters are not recommended. Furthermore, the use of water heater units that are not sealed combustion run the risk of leaking combustion gases into the living spaces. Costly and time consuming combustion appliance safety testing is required for these units to ensure life safety. The use of sealed combustion units provides a cost effective alternative that resolves this issue. 8/10/2016 1 of 5
Description of opportunity The need to reduce energy costs and to eliminate installations requiring combustion appliance safety testing can be addressed by allowing the use of crossover units similar to the RGH-75 residential water heaters for program certification in place of the required 40 gal or 50 gal standard units. The use of these units will allow the specification of better performing and substantially more efficient sealed combustion water heating units than what is currently available in the market. These units have the added benefit of significantly reduced space requirements with dimensions of 21 diameter and 47 height. The specification of crossover units will hasten the realization of the many benefits including cost reduction, greenhouse gas reduction and occupant safety. Crossover Sealed Combustion Units Comparison to Currently Available Storage Units The specification of this product type provides substantial energy savings in comparison to the base case unit, in addition to the other non-energy benefits discussed above. This table provides a summary of the energy savings percentage realized by specifying the RGH75 in place of the code base case unit in two example projects. City and Climate Zone RGH-75 Estimated Energy Savings Over Code Basecase Unit (EF=.60) Retrofit (DHW and Hydronic Heating) New Construction (DHW only) San Francisco CZ 3 36% 24% San Diego CZ 7 37% 26% Escondido CZ 10 37% 25% Sacramento CZ 12 36% 24% Palm Springs CZ 15 39% 27% First Hour Ratings The RGH75 crossover units combine the benefits of instantaneous and storage water heater designs without sacrificing performance. These units utilize.5 inch diameter gas supply lines and provide superior First Hour Ratings. The table below provides a comparison to standard storage units base on the AHRI Certification results 1. AHRI Certified First Hour Rating Crossover 20 gal Natural Gas AHRI certified products: 40 & 50 gal Natural Gas HTP RGH-75 AO Smith RHEEM Whirlpool Bradford White 104.5 gallons 70-92 gallons 59-93 gallons 67-70 gallons 55-112 gallons 1 Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Directory of Certified Product Performance; https://www.ahridirectory.org/ahridirectory/pages/home.aspx ; August 2, 2016 8/10/2016 2 of 5
Presentation of model results The opportunities represented by the inclusion of high efficiency sealed combustion water heater units have been quantified using two actual completed projects and their associated energy models. The projects are described below. The savings are presented for five typically encountered climate zones. Example 1 Retrofit Project: combined domestic hot water (DHW) and Hydronic Heating Multifamily project: 6 buildings, 68 units (2, 3 and 4 bedrooms) water heaters providing domestic hot water and hydronic space heating with hot water fan coils. o 72,593 sq.ft. of conditioned floor area o Two, three and four bedroom apartments o One 50 gallon water heater per apartment Water heater used: AO Smith-50 gal with Energy Factor =.62 Funding Program: CTCAC; Target savings 10% RGH75 high efficiency sealed combustion alternative measure o Energy Factor =.83 o Project energy savings = 11.3% Project energy savings = 22% over unit specified for this example project (CZ3 results) City and Climate Zone Model EF San Francisco CZ 3 San Diego CZ 7 Escondido CZ 10 Sacramento CZ 12 Palm Springs CZ 15 Project Percent Improvement TDV 2 Note: TDV =Time Dependent Valuation of Energy 2 Project Therms/year (used) RGH 75 Percent Project Therms Saved Basecase 0.60 0.0% 25,109 24% AO Smith Low Efficiency 0.62 1.0% 24,605 22% AO Smith Cyclone 0.72 6.9% 21,730 12% RGH75 0.83 12.3% 19,093 NA Basecase 0.60 0.0% 16,894 26% AO Smith Low Efficiency 0.62 1.0% 16,394 24% AO Smith Cyclone 0.72 5.4% 14,192 12% RGH75 0.83 8.8% 12,530 NA Basecase 0.60 0.0% 19,267 25% AO Smith Low Efficiency 0.62 0.7% 18,768 23% AO Smith Cyclone 0.72 4.2% 16,366 12% RGH75 0.83 7.1% 14,406 NA BaseCase 0.60 0.0% 29,027 24% AO Smith Low Efficiency 0.62 0.7% 28,525 22% AO Smith Cyclone 0.72 4.9% 25,318 12% RGH75 0.83 9.2% 22,187 NA BaseCase 0.60 0.0% 15,365 27% AO Smith Low Efficiency 0.62 0.4% 14,869 24% AO Smith Cyclone 0.72 2.2% 12,764 12% RGH75 0.83 3.4% 11,282 NA 2 TDV: Time Dependent Valuation of Energy for Developing Building Efficiency Standards, E3/CA Energy Commission, Feb. 2011 8/10/2016 3 of 5
Example 2 New Project: DHW only Multifamily project: Four stories, 60 units o 42,531 sqft of conditioned floor area o One, two and four bedroom apartments o One 50 gallon water heater per apartment Water heater used: AO Smith-50 gal with Energy Factor =.62 Funding Program: CTCAC; Target savings 30% RGH high efficiency sealed combustion alternative measure o Energy Factor =.83 o Project energy savings 6.5% (CZ 3) Project energy savings = 29% over unit specified for this example project (CZ3 results) City and Climate Zone Model EF San Francisco CZ 3 San Diego CZ 7 Escondido CZ 10 Sacramento CZ 12 Palm Springs CZ 15 Project Percent Improvement TDV Project Therms/ year (used) RGH 75 Percent Project Therms Saved Code Standard 0.0% 10,513 36% AO Smith Low Efficiency 0.62 2.3% 9,550 29% AO Smith Cyclone 0.72 6.2% 7,872 14% RGH75 0.83 8.8% 6,759 NA Code Standard 0.0% 10,127 37% AO Smith Low Efficiency 0.62 2.4% 9,159 30% AO Smith Cyclone 0.72 6.5% 7,505 14% RGH75 0.83 9.2% 6,421 NA Code Standard 0.0% 10,037 37% AO Smith Low Efficiency 0.62 2.0% 9,066 30% AO Smith Cyclone 0.72 5.4% 7,417 15% RGH75 0.83 7.6% 6,340 NA Code Standard 0.0% 10,358 36% AO Smith Low Efficiency 0.62 1.9% 9,391 29% AO Smith Cyclone 0.72 5.2% 7,723 14% RGH75 0.83 7.3% 6,622 NA Code Standard 0.0% 9,279 39% AO Smith Low Efficiency 0.62 2.0% 9,066 38% AO Smith Cyclone 0.72 3.8% 6,666 15% RGH75 0.83 5.5% 5,647 NA 8/10/2016 4 of 5
Conclusion There are considerable costs and energy savings available to California multifamily projects if new crossover water heating products which combine the benefits of instantaneous and storage strategies are allowed to be specified for the multifamily housing market. The allowance of these units in the multifamily programs by accepting the 20 gal units where the programs specify 40 or 50 gallon units will benefit residents, multi-family housing operators and project developers through better indoor air quality, lower capital and operating expenses, and reduced construction testing requirements. The enhanced performance of these units would benefit residents, multi-family housing operators and project developers through better indoor air quality, lower capital and operating expenses, and reduced construction testing requirements. Appendices Appendix A: Energy Model Details Appendix B: RGH 75 Product Specifications 8/10/2016 5 of 5
Appendix A: Energy Model Details Following pages
Energy Model Details Example 1: Multiple buildings-existing building built in 1972 6 buildings, 68 units (2, 3 and 4 bedrooms) 72,593 sqft of conditioned floor area Domestic hot water and hydronic space heating with hot water fan coils Target Compliance margin: 10% Modeling software: EnergyPro 5.1.9.12 Envelope: Mechanical: R-6 walls wood framed 16 OC R-11 wood framed roof 16 OC Slab on grade floors Double metal tinted windows U=.79, SHGC=.59 Hollow metal exterior door Hydronic space heating provided by domestic hot water with forced air cooling, 10 SEER, 9.2 EER Existing Ducts located in conditioned space Example 2: Single building Multi-Family- New construction 1 building, four stories, 60 units (1, 2 and 4 bedrooms) Domestic hot water only (no hydronic space heating) Target Compliance margin: 30% Modeling software: EnergyPro 5.1.9.12 Envelope: Mechanical: R-15 walls 2x4 wood framed 16 OC R-38 Cathedral roof wood framed 16 OC Cool roof with Aged solar=.68, Thermal Emmitance=.84 Uninsulated raised slab floor NRFR tested windows U value=.34, SHGC.31 Ducted split heat pumps, HSPF=10, SEER=15, EER=12 Ducts located in conditioned space
Appendix B: RGH-75 Product Specifications Following pages
Residential Water Heater RGH-75F & RGH-100F TM Advanced Heating & Hot Water Systems Fighting the High Cost of Water Heating! Fully Condensing Achieves up to 95% Efficiency Half the Storage & Twice the Btuh Result in a Recovery Rate that is 4 Times Faster than Traditional Storage Units! RGH100 Specifications www.htproducts.com SCAQMD Rule 1146.2 LLC TM
Crossover The TM incorporates the best of both worlds in one unit with its tank and tankless components. The result is one appliance that exceeds all of your hot water needs Fantastic Features We are excited to introduce the new high efficiency Crossover models RGH-75F and RGH-100F. This revolutionary product was designed to be the most highly efficient affordable residential tank type product in the industry. High Performance The Crossover Residential Floor model combines the flow capacity of a 50 gallon tank type water heater with the continuous flow feature found in tankless water heaters. It has dual activation by flow or thermostat sensing which guarantees hot water delivery even with low flow fixtures. It s built in fire tube heat exchanger is surrounded by a stainless steel tank that holds a full 20 gallons of up to 167 degree hot water and then mixes the delivered temperature down through a ASSE 1017 mixing valve and can thus fill a 40 gallon tub at the same rate as a traditional 50 gallon tank type water heater. The RGH 75 and 100 can also produce more first hour delivery than conventional 50 gallon water heaters. These two new models will change the way people view residential water heating and it is only available through HTP and our agent partners. Extra thick insulation combined with small water volume storage result in very low standby loss High altitude compliant certified up to 10,000 ft. above sea level All stainless steel tank construction with integrated fire tube heat exchanger design Endless hot water - advanced temperature control - compatible with recirculation systems Preset for natural gas ships with a liquid propane conversion kit Eco-friendly and low NOx combustion system leave almost no carbon footprint Air handler application: Combination heating & DHW Includes an ASSE 1017 domestic rated thermostatic valve (prepiped) increasing 1st draw capacity & temperature control
Compare the RGH with the Competition Crossover Tank Type Tankless Features Performance Savings Materials Installation Display Dimensions Efficiency Ultra Lo NOx Complaint RGH-75.83 EF.88UEF RGH-100 50 Gal. Atmospheric 50 Gal. Power Vent 199K Btuh 199 Btuh (Non Condensing) 95% TE.60 EF.70 EF.95 EF.82 EF YES YES NO NO Varies by Model Varies by Model Btuh 75,000 100,000 40,000 40,000 199,000 199,000 First Hour Rating @ 90 F Rise 107 130 88 90 NO NO 30 Gal. Dump Capabilities YES YES YES YES NO NO Zero Flow Activation YES YES YES YES NO NO Optional Two- Temperature Delivery Capability (with kit) Annual Operating Energy Cost (NG) Tank Heat Exchanger Annual HX Anti-Scale Maintenance Required YES YES NO NO NO NO $196 Stainless Stainless N/A - TE Classification Stainless Stainless $272 $233 $172 $199 Glass Lined Carbon Glass Lined Carbon Glass Lined Carbon Glass Lined Carbon Stainless / Copper Stainless / Copper Copper Copper NO NO NO NO YES YES Venting PVC PVC B-Vent PVC PVC Stainless Category III Vent Length 2" at 50' 2" at 50' 3" at 50' 3" at 100' 2" at 50' 3" at 50' Space Saving Low Profile Vent Capability Anti-Draft Direct Vent Capable YES YES NO NO NO NO YES YES NO NO YES YES Field Convertible YES YES NO NO Varies Varies Anti-Scald Mixer (ASSE 1017) Digital with Error Codes YES YES NO NO NO NO YES YES NO NO Varies by Model Varies by Model Height 38.6" 38.6" 57" 50 3/4" 23 5/8" 20 1/2" Diameter 21" 21" 22" 24" N/A N/A Width 21" 21" 22" 24" 17 3/4" 13 3/4" Depth 21" 21" 22" 24" 11 1/4" 10 1/2" Weight 110 lbs. 110 lbs. 165 lbs. 198 lbs. 63 lbs. 51 lbs.
RGH-75F & RGH-100F Produce More Hot Water than a Standard Tank with 40% Less Space Required than a Standard Tank A Closer Look Inside Super Durable All Stainless Fire Tube Heat Exchanger
Water Heater Tank + Tankless Water Heater =
RGH-75F & RGH-100F GALLONS PER HOUR @ 90ºF 50G Tank RGH-75F RGH-100F Model RGH-75F RGH-100F Efficiency EF.83 (Energy Factor) UEF.88 (Uniform Energy Factor) TE 95% (Thermal Efficiency) Installation Vent Run Condensate Discharge Condensate ph Level Gas Type 3 PVC or Polypropylene 2 PVC or Polypropylene Indoor / Floor Standing Up to 100ft, 6 Elbows Max (3 pipe) [3ft Deduction Per 45º Elbow] [5ft Deduction Per 90 º Elbow] Up to 50ft, 6 Elbows Max (2 pipe) [5ft Deduction Per 45º Elbow] [8ft Deduction Per 90 º Elbow] 2GPH 4 ph Preset for NG / LP Conversion Kit Included Unit Connections Gas 1/2 or 3/4 Female NPT (3/4 by 1/2 Bushing Adapter Included) Water Electricity Condensate 3/4 Male NPT Dedicated 120VAC, 60Hz w/3 Pronged 5 1/2 ft. Power Cord 1/2 Male NPT Connection Gas Input Rate Hourly Max: 75,000 Btuh Min: 37,500 Btuh Max: 100,000 Btuh Min: 50,000 Btuh Gas Supply Pressure NG / LP 3.5 WC to 14 WC / 3.5 WC to 14 WC Ignition System Spark Ignition, No Pilot Burner System Gas Valve System Air Ratio Negative Pressure First Hour Output @ 77 F / 90 F 125 Gallons / 107 Gallons 160 Gallons / 130 Gallons Reserve Tank Tank Material Temperature Sensing Domestic Temperature Control 20 Gallons Stainless Inner Tank and Hot Outlet Discharge Pipe Sensors Thermostatic Mixing Valve - ASSE 1017 Rated Domestic Temperature Settings Range 120 F Factory Preset / Adjust Knob 70 F to 145 F Tank Storage Temperature Settings Normal 127 F / Hotter 147 F / High Output 165 F Unit Dimensions (D x H) 21 x 47 Unit Weight 110 lbs Safety Devices T&P Valve, Vent Blockage APS, Flame Rod, Fan RPM Check, Eco Burner Plate (305º F), Eco Water Limit (194º F) Optional Accessories 3 or 2 Horizontal Terminal, Concentric Venting Kit, Condensate Neutralizer Kit 272 Duchaine Blvd, New Bedford, MA 02745 MKTLIT-XX - 06 / 2016 HTP In accordance with our company policy of ongoing product improvement, HTP Inc. reserves the right to make changes without prior notice. All weights are approximate.