Laboratory Evaluation of Hybrid and Advanced Water Heaters: Performance Overview in Hot Humid Climate American Council for an Energy Efficient Economy ACEE Hot Water Forum Nov. 4-5, 2013 Carlos J. Colon carlos@fsec.ucf.edu A Research Institute of the University of Central Florida
Hot Water Systems (HWS) Laboratory FSEC Grounds, Florida (east coast) 2009 Present (Currently fourth testing rotation) 2
Hot water gallons Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Inlet Water Weighted Avg. (F) HWS Lab. Testing Conditions, Cocoa, FL 120 F Thermostat Setting Draws @1.5 gpm flowrate Real mains inlet water and ambient temperature Hot water draw schedules 14 12 10 8 6 4 2 0 ASHRAE (64.3 gpd) NREL/BA (varies monthly) 0 2 4 6 8 10 12 14 16 18 20 22 24 85 75 65 55 BA_Jan ASH 90.2 BA_Jul January February March April May June July August September October November December 0 50 100 2009 2010 2011 NREL/BA High = 67 Low= 42 Average 54.8 gpd 3
Hot Water Systems Laboratory, Cocoa, FL High Efficiency Systems Evaluation Baseline Electric 50 Gal. EF=0.91 Basleine Nat. Gas 40 Gal. EF=0.59 Retrofit HPWH +Solar Col Diff. 80 gal / 40 ft 2 dc pump (w/ps) ICS 40 gallon + Integrated 50 Gallon HPWH Solar Col Diff. 80 gal/40 ft 2 dc pump (PV) + Tankless NG condense Std 50 Gal. Electric w/cap-wrap Orange labels indicate Electric Hybrid Integrated systems (2012). 4
COP Hot Water Draw Schedule Impact on Efficiency 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 Standard Electric 50-gallon Water Heater EF=0.91 Smaller draws during summer - Reduced deltat ( T) due to seasonality of Inlet water temperatures. Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug ASHRAE NREL BA 5
COP Efficiency 50 gal. HPWH Efficiency by Draw Pattern 4.5 90 4 85 3.5 3 2.5 2 1.5 1 0.5 58.2 ⁰F Dip 68.5 ⁰F Dip 80 75 70 65 60 55 Ash 90.2 NREL/BA Lab Temp 0 Jun Aug Oct Dec Feb Apr Jun Aug 50 2010 2011 6
GE Heat Pump Water Power Consumption 52 ⁰F Heating element = 2.4% Compressor 1667 hrs/yr (Average = 4.6 hrs/day) 7
Standard Electric vs HPWH (50 gal.) Daily Outlet Temperatures Compared * ASHRAE Draws NREL/BA Draws Indicates shortage of capacity due to slow recovery of Heat Pump * Temperatures are weighted averaged by volume 8
Hybrid Integrated Collector Storage with Heat Pump Water Heater Compressor operation Reduced by ~650 hrs/yr. + 50 gallons 40 gallons on Roof 9
Hybrid Solar Thermal Collector with Retrofit Heat Pump Water Heater Heating Element Disconnected 10
Coefficient of Performance (COP) Solar Augmented HPWH vs HPWH 7 6 5 4 3 ICS_HPWH SOL_AIRTAP HPWH Only 2 1 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan 11
Performance History of Electric-Based Water Heaters at FSEC HWS Laboratory (Cocoa, FL) kwh/day Electric Reduction ICS+Int HPWH Sol+Ret HPWH 1.7 1.9 < 2 kwh/day! 78% 75% HPWH 2.75 64% Sdiff/PV Pump 3.03 60% Sdiff/AC Pump 3.32 56% ICS+ 50 gal 4.9 36% Tankless E 7 8% E-50 Cap/Ins 7.3 4% Baseline E-50 7.61 0 1 2 3 4 5 6 7 8 9 kilowatt-hours / day 12
Performance History of Electric Water Heaters at FSEC HWS Laboratory (Cocoa, FL) ICS40 + HPWH 50 Sol80+Ret HPWH HPWH-80* HPWH-60* HPWH-50 Sdiff 80 PV Pump Sdiff 80 AC Pump Solar 80 Polymer* ICS40 + E-50 gal Tankless E E-50 Cap/Ins E-50 1.27 0.89 0.89 0.84 2.71 2.46 2.27 2.27 2.26 1.85 2.07 3.87 0 1 2 3 4 5 6 Efficiency (COP) [EF or SEF] [N/A] [N/A] [2.4] [2.4] [2.35] [2.8] [3.5] [N/A] [2.4] [0.98] [0.91+] [0.91] * Denotes systems in current 2013 testing rotation; 5-month of data only 13
Daily Average Weighted Hot Water Delivered Temperatures All Draws (⁰F) NREL/BA (⁰F) Min. Delivered (⁰F) Max. Delivery (⁰F) Electric Std. - 50gal. 118.5 117.9 115.8 120.9 ICS+Integrated HPWH 118.0 117.0 113.4 119.7 HPWH 50 gal. 118.1 116.9 112.2 119.9 Solar 80 +Retrofit HPWH 117.4 117.1 106.2 126.9 Baseline Std. NG - 40 gal. 121.2 120.8 116.3 124.1 Tankless Condensing NG 117.2 116.6 112.3 118.4 Tankless NG 116.6 117.0 111.4 118.4 Solar 80 gallon + Tankless Cond. NG 113.5 107.2 105.0 134.4 Standard heaters provide Best Overall Consistent Hot water temperature delivery 14
kwh/day Simulations for Electric HPWH Atlanta, Georgia 12 10 8 6 50 Gal. HPWH EF = 2.35 Std. Electric 50 Gal. 9.80 11.31 10.61 Living Garage Basement ********* 4 2 3.80 * 4.38 4.11 Living Garage Basement 0 * Does not reflect building heating penalty during winter season (+94 kwh) Simulations Performed using BEopt 2.0 Two-story home 1500 ft 2, 130 F setting 15
Average Hourly Site Energy Demand (kbtu/hr.) kilowatts (kw) Standard vs. Hybrid Water Heaters Average Daily Energy Demand Perspective 8 7 6 5 Standard WH s 2 1.5 Sol_Tnkless NG40 4 Tnkles_cond 3 1 E50 2 1 Hybrid WH s 0.5 HPWH ICS_HPWH 0 0 4 8 12 16 20 24 0 16
Larger Capacity: HPWH Improvement Areas Based on Consumer Feedback True 50 65 gal. Tank Quiet Fan / Lower Noise Will ducting help with fan Noise? Heat element simultaneous with compressor operation Selective air ducting (3-way configuration) Ducting kit Cost Increment Real Time Clock (RTC) Timer to Allow compressor runtime schedule set by user Consumer Warranty, Service and Training Information. Easy access to maintenance: condense drain, filter, anode. Reliability: Refrigeration (Compressor/coils) Longevity Price/Reward Investment 17
Questions? Solar Thermal Polymer Glazed Collectors Hybrid Water Heaters www.infomonitors.com/hws/ Cap and Wrap (Argon-filled) Tank Insulation 18