| A–W | Air—water heat pump |
| ACH | Air-change rate |
| COP | Coefficient of performance |
| G–W | Ground—water heat pump |
| GW | Grey water unit |
| HP | Heat pump |
| NG | Natural gas |
| PV/T | Photovoltaic/thermal |
| RES | Renewable energy sources |
| SCW | Sanitary cold water |
| SHS | Seasonal heat storage |
| SHW | Sanitary hot water |
| SPF | Seasonal performance factor |
| STC | Solar thermal collectors |
| W–W | Water—water heat pump |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.