Water Heating

Reduce Hot Water Energy Consumption
There are three basic ways to reduce the energy consumed for making hot water.

1. Reduce the amount of hot water you consume.
   Faucet aerators can reduce the amount of water flow by up to 50%, while typically delivering sufficient hot water for your needs. Installing shutoff valves on water nozzles is a convenient way to quickly start and stop the flow of hot water. These nozzle shutoff valves leave the cold water/hot water mix intact, which is normally attained by running the water continuously.
   
   
2. Minimize the amount of energy lost in your hot water system.
   Lowering the temperature of your hot water can substantially reduce the amount of energy needed to heat it. A 10 °F reduction in water temperature can result in 3-5% reduction in energy usage. Insulating your hot water tank and piping can reduce your energy consumption by 4-9%. When insulating, be careful to leave openings for areas on your water heater that need to be accessed. Also, check with the tank manufacturer to make sure insulating your tank is not prohibited.
   
   
3. Change to a high-efficiency water heater.
   The most energy-efficient water heater is a heat pump water heater (HPWH). The table below shows the efficiency of the most common methods of water heating. Energy factor is the annual energy output divided by the energy input.




Energy Factor	Typical New Unit	Most Efficient on Market
Water Heater
Oil-fired	.48 - .53	.60 - .63
Gas-fired	.51 - .56	.71 - .86
Electric Resistance	.87 - .91	.96 - .98
HPWH*	2.50 - 3.50	3.10 - 3.50

*Note: HPWH's energy factor can be greater than 1.0 (i.e., it produces more energy than it consumes), because it ‘draws in’ energy from its environment, energy which is typically lost if not "reclaimed."