A heat pump water heater (HPWH) can provide residents with environmental, health & safety, and financial benefits. In order to evaluate whether a HPWH makes sense for your home, consider the following factors.





  • Garages and basements are the ideal locations for installing a HPWH. With certain precautions taken, HPWHs can also be installed in attics, indoor closets and outdoor water heater closets.
  • HPWHs need extra space around them for sufficient airflow. Most manufacturers recommend that a space be bigger than 700 cubic feet (79 square feet) and recommend that smaller spaces have a louvered door. There also needs to be a minimum clearance of 6" above and around the HPWH.
  • HPWHs need a drain for condensate. HPWHs can operate in both electric resistance mode and the more efficient heat pump mode. When operating the water heater in heat pump mode, it will dehumidify and cool the surrounding space.
  • Noise should be considered when choosing a site for a HPWH. The mechanical components produce 55 to 65 decibels which is slightly louder than a refrigerator.




Most HPWHs require a dedicated 30 amp breaker and a 240V electrical conduit from the electrical panel to the location of the HPWH unit.





While a household of three to four people might utilize a 50-gallon gas water heater, the best option for the same household would be a 80-gallon HPWH. The bigger tank allows the HPWH to support higher water draw volume without the need to operate using the less efficient electric resistance mode.




Review our Resources page for FAQs, helpful links and more.

Contact CPAU

Contact the Home Efficiency Genie, CPAU's expert on energy and water efficiency. The Genie can provide unbiased advice on whether a HPWH makes sense for your home.

PHONE: (650) 713-3411

EMAIL: utilityprograms@cityofpaloalto.org



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