1. Residential Hot Water Use Patterns and Energy Efficiency April 29, 2014 Advanced Energy Conference - Albany Hugh Henderson CDH Energy Corp. hugh@cdhenergy.com Supported by NYSERDA US DOE Building America 1

2. Why does DHW Matter? Water heating 2 nd largest load in NY Homes –Bigger than cooling; approaching magnitude space heating in some highly-efficient homes –New technologies are being developed Performance differences between wide array of DHW technologies not always clear –Performance/efficiency depends on water use (64 gallons/day may not apply any more) –DOE Test and Rating Procedures to determine EF are currently being revised –Large impact of distribution system performance 2

3. Project Overview Side-by-Side Laboratory Testing –Impose the same water use pattern on systems and compare performance –Compare solar water heating to other technologies Field Testing –Confirm actual field-measured performance –Quantify load profiles in actual homes –Understand impact of HW distribution Technology Transfer –Develop a Guide to help consumers 3

4. Laboratory Testing Standard Gas Water Heater (WH) 4 Unit 1 STD GAS (EF=0.58) Unit 2 PWR VNT GAS (EF=0.67)

5. Laboratory Testing – Solar/HPWH 5 Unit 3 SOLAR (SEF=3.2) Unit 4 SOLAR DRAIN Unit 8 HPWH (EF=2.4)

6. Laboratory Testing High Efficiency Gas 6 Unit 6 HE COND TANK (TE=0.96) Unit 7 HYBRID (TE=0.90) Unit 5 TANKLESS (EF=0.94)

7. Lab Instrumentation Measure Flow, ΔT & Q out Fuel input Control Inlet water temp Flow rate Specify as daily profile (multiple draws: time, flow, duration) 7

8. Imposed Water Use Profile Proposed “Normal Use” pattern 8

9. Realized Performance in Lab “Normal Profile”, Sep-18 to Oct-31 9

10. Field Testing Goal Measure HW daily use profiles (all 18 sites) Measure inputs, thermal outputs and efficiency as well as component status and operating conditions under actual use patterns (at 3 detailed sites) HW distribution measurements at 5 sites. Install temperature sensors on distribution piping to: –allocate water draws to key end uses (sinks, showers, dishwashers, etc) –Estimate HW “waste” in distribution piping 10

11. 15-minute Profile – 2 People February 11

12. A Kitchen Sink Draw Event 12

13. Classification Success Rate 13 Useful = T is Over 90°F at Fixture

14. HPWH and Resist Elements 14

15. Summary Conventional systems perform closest Rated EF High efficiency condensing systems below expectations Solar systems and HPWH systems strongly dependent on operating conditions Draw patterns (and specific events) affect performance –For instance, resistance element operation 15