Skip to content
Log in Calculators

Heat Pump Water Heater Savings Calculator

Annual saving, payback and the space-cooling effect from an electric resistance to heat pump swap, screened against the installation ambient temperature.

Inputs

How much hot water you use

The DOE test procedure defines four draw patterns with reference daily volumes (10 CFR 430 Subpart B Appendix E Table III). Pick the closest, or choose Custom and enter your own gallons.

Used only when Custom is selected above.

Temperatures

Year-round average groundwater temperature. Note that the DOE rating procedure assumes 58 F (Appendix E 2.3).

A heat pump heats more slowly than an element, so some owners run the tank hotter. Higher storage also raises standby loss.

The space the unit draws its heat from: basement, garage, utility closet. Manufacturers commonly rate heat pump mode down to about 40-45 F ambient, below which the unit falls back to resistance elements and the savings disappear.

Units and money

Electric resistance storage runs about 0.90-0.95 on the EnergyGuide label.

Current heat pump water heaters rate roughly 2.0-4.0 on the EnergyGuide label. Read the label of the model you are considering.

All-in cents per kWh from the bill, including supply and delivery.

Heat pump unit plus any circuit changes, minus what the replacement resistance unit would have cost.

Enter 0 if none applies. Rebates and tax credits on heat pump water heaters change often and vary by utility and state.

Result

Annual saving
—
Simple payback
—
Net cost after rebate
—
Heat pump annual energy
—
Ten-year net saving
—
Annual energy saved
—
Existing unit annual energy
—
Energy reduction
—
Space cooling and dehumidification
—
—
—
Side effect to plan for
—
Where this stops applying
—
Calculation details
Daily hot water used
—
Annual heat the water absorbs
—
Average temperature rise
—
Space cooling in electric terms
—

What to check

  • UEF of the existing unit and of the heat pump unit, from the EnergyGuide labels
  • The air temperature of the space it would be installed in
  • Installed cost difference and any utility or program rebate

Standards referenced

  • DOE Uniform Energy Factor test procedure — 10 CFR Part 430, Subpart B, Appendix E · Uniform test method for measuring energy consumption of water heaters; UEF ratings on nameplates and EnergyGuide labels come from this procedure.
  • ENERGY STAR Water Heaters specification — Current specification (see product list for UEF thresholds) · Efficiency thresholds for certified heat pump water heaters; UEF cutoffs change by revision, so confirm against the current list.

Related calculators

Screening estimate only. The result panel lists the limits that apply to this calculation. Verify nameplate data, rates, groundwater temperatures and installer quotes before deciding, and have gas, venting and electrical installations checked against the local code by a licensed contractor.

Saved calculations

Keep the assumptions with the result.

Save this calculation to return to the inputs, result, and report anytime.

Sign in to save Create account

Sign in or create an account to save this calculation.