Domestic Hot Water on an Air to Water Heat Pump
During the electrification of our industry there are limited options to create DHW.
a. Use a minimum 80-gallon electric water heater
b. Preheat the water before the water heater
2. Indirect water heater (IWH)
a. Upsize the tank size
b. Use a tank with an electric element as back-up
3. Tankless water heater
a. Use pre-heater water into the electric tankless water heater
b. No need to pre-heat inlet DHW water to gas tankless water heater
4. Heat Pump Water Heater
a. No need to temper the inlet water
Fig 1 - AWHP with Electric water heater with pre-heating water through a flat plat heat exchanger. The pre-heated water will be attached to the cold inlet on the water heater.
Fig-2 - AWHP with an Indirect Water Heater. The AWHP water will be piped through the coil in the IWH.
Fig 3 - AWHP with a Tankless water heater. While this seems overkill it is a way to control the cost of operation. This is especially helpful with larger hot water demands.