Domestic Hot Water & Air to Water Heat Pump

Domestic Hot Water on an Air to Water Heat Pump

When installing an Air to Water Heat Pump (AWHP), you can add domestic hot water (DHW) when the heat pump is installed or any time afterward, like when the existing DHW water heater fails as part of what I call the Building Blocks theory.

During the electrification of our industry, there are limited options to create DHW.

1. Electric water heater
  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 a backup
3. Tankless water heater
  a. Use pre-heated water in 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

Below are some sample applications. The drawings are incomplete for simplicity. Always follow the manufacturers recommendations.

Fig 1 - AWHP with an Electric water heater with pre-heating water through a flat plate 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 may seem overkill, it is a way to control operational costs. This is especially helpful with larger hot water demands.

Disclaimer:The information found on this website is for informational purposes only. All preventive maintenance, service, and installations should be reviewed on a job-by-job basis. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accepts no responsibility for any improper information, application, damage to property, or bodily injury resulting from the application of information found on this website, as a professional should review it.