1. Chapter 9: Water Heating To be used with the Guide to Building Energy Efficient Homes in Kentucky

2. Hot Water Use 90 gallons per day 50 gallons per day

3. Energy Factor Energy Factor (EF) = a measure of the overall efficiency of a water heater Includes: ―Recovery efficiency ―Standby losses ―Cycling losses

4. Energy Conservation Water conservation measures =

5. Energy Conservation New homes: Keep hot water pipe run as short as possible Use a manifold plumbing system

6. Energy Conservation

7. Water heater setting Temperature = 120 ° F – Provides plenty of hot water – Decreases risk of scalding – Select dishwasher with booster heaters

8. Energy Conservation

9. Insulate the first four feet of all pipes Use low-flow showerheads

10. Energy Conservation Install heat traps Install low-flow aerators on sink and lavatory faucets

11. Energy Conservation 1 quart Every 3 months, drain ~ 1 quart

12. Gas Water Heaters Energy Factors (EF) for ENERGY STAR ® Gas Water Heaters TypeEnergy Factor Gas Storage (ending 8/31/2010)≥ 0.62 Gas Storage (beginning 9/1/2010)≥ 0.67 Whole-home Gas Tankless≥ 0.82 Gas Condensing Storage≥ 0.90

13. Gas Water Heaters Gas water heater efficiency is affected by: Burner design Shape of the flue baffles Amount of surface area between the flue gases and the water Presence of blowers for venting and delivery of combustion air

14. Gas Water Heaters Fuel-fired water heaters, in conditioned space: Must be in a sealed mechanical room ―Fresh air inlets To avoid the sealed mechanical room ―Use a fuel-fired water heater that includes provisions for outside combustion air Direct-vent unit with a double flue pipe

15. Gas Water Heaters Higher efficiency units have: Blowers for venting and delivery of combustion air More sophisticated energy features ―Electronic ignition ―Flue dampers ―Condensing heat exchangers EF > 0.90

16. Electric Water Heaters Higher efficiency – EF > 0.97 – Extra cost is low compared to the savings

17. Electric Water Heaters

18. Heat Recovery Units Heat Recovery Unit = Desuperheater Recovers excess heat from air conditioner or heat pump to provide “free” hot water Heat Recovery Unit = Desuperheater Recovers excess heat from air conditioner or heat pump to provide “free” hot water

19. Heat Recovery Units In summer: – Desuperheater can usually provide 100% of the hot water needs of a family and improve the efficiency of the air conditioner In spring and fall: – Desuperheater is ineffective In winter: – Desuperheater is more effective and saves money

20. Heat Recovery Units Performance of a desuperheater is affected by: Size and efficiency of the water heater and cooling equipment – Cost $550 to $750 – Annual savings = $50 to $180 – Make sure that it does not void any mechanical equipment warranties – Check the water supply to see if any buildup may occur

21. Solar Water Heaters Images Courtesy: http://www.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=12770

22. Solar Water Heaters Cost effective option because: Current cost of energy Tax incentives at state and federal levels Can be oversized – Used to assist with heating a home

23. On Demand Water Heaters On Demand Tankless Water Heater (gas)

24. On Demand Water Heaters Save energy: No storage tank Gas-fired units usually heat water more efficiently than gas tank type water heaters

25. Summary