What is a good heat pump balance point?

Lower is better for running cost. The right target depends on your climate and backup fuel.

Where do I find capacity at 17°F?

In the maker’s extended performance tables or the AHRI certificate.

Why does my heat pump use aux heat above the balance point?

Defrost cycles, big setpoint jumps or control settings. Have the controls checked.

Is the balance point the same as the switchover temperature?

No. Switchover in a dual-fuel system can be set by fuel price as well as capacity.

HyreHVAC tools

Heat pump balance point calculator

Where the heat pump’s capacity line crosses your house’s heat-loss line. Enter numbers from your Manual J and spec sheet.

Your figures nothing pre-filled Straight-line house load and straight-line capacity through the 47°F and 17°F ratings.

The short answer

This heat pump balance point calculator finds the outdoor temperature below which your heat pump cannot cover the house’s heat loss on its own.

Enter the design heat loss from a Manual J, your design temperature, and the heat pump’s capacity at 47°F and 17°F from its spec sheet or AHRI certificate. It also shows the backup heat needed at the design temperature.

Find the balance point

Numbers from your Manual J and spec sheet. Nothing is emailed.

— Balance point

— Backup needed at design

— Backup in kW

— Heat pump covers

What this assumed

—

Straight-line screen. Not a Manual J or Manual S. HyreHVAC does not size or install equipment.

What is the balance point?

A house loses more heat the colder it gets outside. A heat pump delivers less heat the colder it gets. Plot both and they cross. That crossing is the thermal balance point. Above it, the heat pump carries the house. Below it, backup heat makes up the gap. See balance point temperature.

DOE notes that heat pumps with electric backup need controls so the strips do not run when they are not needed. Knowing the balance point helps set those controls.

How does the calculator work?

House load is a straight line from zero at the temperature where your house needs no heat (65°F by default) to your design heat loss at your design temperature. Capacity is a straight line through the 47°F and 17°F ratings, extended past them. The tool solves for where they meet.

Real capacity curves bend, and defrost takes some capacity away. Cold-climate units often publish 5°F data; if yours does, the line between 17°F and 5°F is a better guide at the cold end.

Where to get the inputs

Design heat loss
From an ACCA Manual J for your house. Not from square footage.
Design temperature
Your local winter design temperature; the Manual J report states it.
Capacity at 47°F and 17°F
The maker’s extended performance data, or the AHRI certificate for the matched system.
Do not guess the capacities
A brochure "tons" figure is not the 17°F capacity.

What to do with the result

A low balance point means less backup heat. If the gap at design is large, ask whether a cold-climate model, a different size or a dual-fuel setup fits better. See cold-climate heat pump data.

Questions this calculator answers

What is a good heat pump balance point?: Lower is better for running cost. The right target depends on your climate and backup fuel.
Where do I find capacity at 17°F?: In the maker’s extended performance tables or the AHRI certificate.
Why does my heat pump use aux heat above the balance point?: Defrost cycles, big setpoint jumps or control settings. Have the controls checked.
Is the balance point the same as the switchover temperature?: No. Switchover in a dual-fuel system can be set by fuel price as well as capacity.

Sources and methodology

Figures dated October 26, 2026. Last reviewed September 18, 2026.

US DOE Energy Saver: Air-Source Heat Pumps (archived copy, 2025) (US DOE Energy Saver, retrieved 2026-10-26. How a heat pump transfers heat, the reversing valve, defrost, and auxiliary electric resistance heat. The live energy.gov page returned 404 on the check date.)
ACCA: Manual J, Residential Load Calculation (ACCA, retrieved 2026-10-26. The ANSI-recognised method for sizing heating and cooling equipment to a house.)
AHRI Directory of Certified Product Performance (AHRI Directory of Certified Product Performance, retrieved 2026-10-26. Look up the certified rating of a matched outdoor and indoor combination.)

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