Glossary · Hot water
Heat pump water heater (HPWH)
Also called: heat pump water heaters · hybrid water heater · heat pump hot water heater
An electric water heater with a small heat pump on top that pulls heat from the surrounding air, using far less electricity than a standard tank.
What it means
The heat pump does most of the work, with electric elements as backup for heavy demand. It cools and dehumidifies the room it sits in, which can help in a damp basement in summer. It needs enough space, airflow and a condensate drain, and 120-volt plug-in models make replacing a standard tank easier.
Why it matters in an audit
Water heating is a big slice of home energy use, and a heat pump water heater uses a third to a half of the electricity of a standard electric tank, so it's often a high-value upgrade that many programs rebate.
Typical numbers
Reference values with their sources. Your auditor’s report gives the figure for your own house.
| What | Value | Source |
|---|---|---|
| ENERGY STAR minimum (UEF) | 3.30 for integrated models; 2.20 for 120-volt/15-amp and split-system models | energystar.gov ↗ |
| Best available vs. standard electric tank (DOE FEMP) | UEF 3.93 vs. 0.95 | energy.gov ↗ |
| Efficiency vs. conventional electric (DOE) | Two to three times more efficient | energy.gov ↗ |
| Share of home energy used for water heating (DOE) | About 18% | energy.gov ↗ |