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Heat Pump Water Heater

Installed correctly, heat pump water heaters can cut utility expenses while providing additional cooling and dehumidification during hot weather.

Water heating is the second largest energy expense in a home – typically 18% of the total utility bill. High-efficiency heat pump water heaters reduce heat loss with well-insulated tanks and produce heat much more efficiently using the refrigerant cycle rather than electric resistance. This process also provides additional cooling and dehumidification to the space, which can be useful during hot weather and a penalty during cold weather.

Checklist

This U.S. Department of Energy checklist includes important specifications that can contribute to a complete and quality installation. All work shall comply with these specifications, all relevant codes and standards, and all manufacturer installation instructions. The contractor shall check each box on the checklist below and sign and date at the bottom to certify the work is completed.

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Preparation


The existing hot and cold water pipes around the water heater shall be inspected for water leaks before installation, and any leaks found shall be reported to the homeowner for repairs before continuing the work.

The new replacement water heater shall be sized based on the first-hour rating.

Installation


The new water heater shall be ENERGY STAR certified and shall be installed in compliance with manufacturer’s specifications and relevant industry standards.

The new heat pump water heater shall be installed in a space with adequate clearance to ensure efficient operation, maintenance, and flow. The minimum space shall be 750 ft3 or as specified by the manufacturer. If the space where the water heater is located is smaller than specified, manufacturer requirements shall be followed (e.g., connecting the space to a larger space via a louvered grille in a wall or door or to the outdoors via ducting provided by the manufacturer).

Where water leakage from the water heater could cause damage to the home, a building code-compliant emergency drain pan shall be installed with a ¾" drain line or larger running to a drain or pumping to daylight.

The water heater shall be installed on blocks within the drain pan when a drain pan is included.

The temperature shall be set and the pressure relief valve shall be installed according to manufacturer’s specifications; the discharge tube shall be terminated within 6 inches of the floor, or as prescribed by local code.

For a closed water supply system (i.e., with a back-flow preventer in the cold water supply), provisions shall be made to control thermal expansion (i.e., install an expansion tank if needed).

The hot water line exiting the water heater shall be installed with a heat trap configuration or heat trap nipple to prevent thermosiphon losses.

Where required by local codes, or if desired, a mixing valve shall be installed to reduce water temperature at the tap to prevent scalding.

All accessible hot water pipes connected to the water heater shall be insulated with a minimum of R-3 pipe insulation.

A condensate drain shall be installed in accord with local code.

Commissioning


The water heater shall be commissioned in compliance with manufacturer’s specifications and relevant industry standards.

Maintenance procedures shall be reviewed with the homeowner (e.g., filter, condensate, check for leaks, draining and flushing).

Once the system has been filled and purged, the functioning safety controls and operational controls shall be verified and the system shall be inspected for water leaks.
Heat Pump Water Heater

Tips to Sell Quality Installed Home Improvements

Home Improvement Expert is a valuable tool for organizations committed to quality installed work. The following tips help optimize the value of this tool when selling home improvements:

Trust Matters: Inform homeowners how your work conforms to this world-class expert guidance. Recommend they visit the DOE website as evidence these are indeed official best practices.

Knowledge Matters: Take advantage of the Building America Solution Center as a resource for becoming an expert on these projects.

Clarity Matters: Tell prospective clients to contrast your expert-recommended best practices with other contractors.

Value Matters: Advise prospective clients to insist other bids also include these checklists to ensure equivalent quality work.

Message Matters: Showcase on your website and marketing materials that your company uses the highest quality best practices specified on HIE Checklists.

Experiences Matter: Provide visual evidence contrasting the difference between poor and high quality work such as infrared images; pre- and post-energy bills; short and long warranties; and simple charts and graphics depicting performance advantages.

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Disclaimer

This content is a work created with funding provided by the United States Department of Energy under Contract no DE-AC05-076RL01830 for the operation of Pacific Northwest National Laboratory. The information and guidance provided by Pacific Northwest National Laboratory (PNNL) in the content are intended solely for educational purposes only and do not constitute formal training or certification. It is provided with the explicit understanding that neither the United States Government nor the United States Department of Energy, nor the Contractor, nor any or their employees, nor any jurisdiction or organization that has cooperated in the development of these materials, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, software, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Viewers assumes full responsibility for all actions that they may take from information provided in this content including ensuring the safety, code compliance, and proper functionality of any products they choose to install. Installation and use of such products should be performed in accordance with local regulations and manufacturer instructions.