Heat recovery heat pumps (HRHPs) are heat pumps that use energy that would otherwise be wasted. The heat pump converts this energy to a more useful level by increasing its temperature. HRHPs include closed cycle heat pumps, mechanical vapor recompression (MVR) or open cycle heat pumps, and dehumidification heat pumps.

There are many environmental benefits to heat recovery heat pumps. These ecological advantages are often accompanied by economic benefits. These include reductions in energy, water, and water treatment chemical use. A need has arisen to quantify these benefits, and this is the purpose of these guidelines. Often, there are qualitative benefits as well, such as process improvements and the availability of space cooling, and these are also indicated.

To develop these guidelines, eight sites that represent a broad spectrum of application were selected from the thirty sites analyzed by ASHRAE RP-656. Worksheets linked to the sites are provided, along with drawings of the processes involved. Each worksheet represents a different environmental benefit calculation and can be used to determine the potential improvement for a system similar to the site in question. A disk copy of the worksheets is included. An industry better informed of the benefits will be more likely to adopt HRHP technology.