Heat pump electrical panel requirements
A heat pump replaces your air conditioner, and many include electric strip heat as a backup. That strip heat can add a lot to the load.
What counts
- The compressor: Panel Check uses about 1,200 VA per ton as a rule of thumb. Your equipment nameplate gives the real figure.
- Strip heat: counted at 65% of its nameplate rating.
- Replaces A/C: the heat pump is used in place of central air conditioning, not added on top.
Worked example: 3-ton heat pump
Illustrative home, not yours: 1,800 sq ft, electric range (12,000 VA), electric dryer (5,000 VA), electric water heater (4,500 VA), 2,000 VA of other fixed appliances and a 4,000 VA central A/C.
With no strip heat:
| General loads: lighting at 3 VA per sq ft, two 1,500 VA small-appliance circuits, 1,500 VA laundry, plus range, dryer, water heater and other fixed appliances | 33,400 VA |
| First 8,000 VA at 100%, the rest at 40% | 18,160 VA |
| Heat pump (3 tons at about 1,200 VA per ton) in place of central A/C | 3,600 VA |
| Total, divided by 240 V | 90.7 A |
| Against a 100 A service | 91% (tight, 80% to 100%) |
With 10,000 VA (10 kW) of strip heat:
| General loads: lighting at 3 VA per sq ft, two 1,500 VA small-appliance circuits, 1,500 VA laundry, plus range, dryer, water heater and other fixed appliances | 33,400 VA |
| First 8,000 VA at 100%, the rest at 40% | 18,160 VA |
| Heat pump (3 tons at about 1,200 VA per ton plus 65% of 10,000 VA strip heat) in place of central A/C | 10,100 VA |
| Total, divided by 240 V | 117.8 A |
| Against a 100 A service | 118% (over, above 100%) |
How Panel Check estimates it
Panel Check uses an NEC-style optional method for existing homes. It adds general loads, counts the first 8,000 VA in full and the remainder at 40%, adds the larger of cooling or heating, then divides by 240 V to get amps. An EV charger is treated as a continuous load, so its breaker size is multiplied by 125%. A result at or under 80% of the service rating reads as fits, up to 100% as tight, and above that as over. The heat pump figure is a rule of thumb; the nameplate on your equipment is the real number.
Frequently asked questions
Do I need strip heat?
That depends on your climate and equipment. Your installer can say what backup heat your system needs, and it changes the panel load.
Can I add a heat pump and an EV charger together?
You can model both at once. Run the check with both and see whether the result is fits, tight or over.
Where do I find my equipment ratings?
The nameplate on the unit and the installer quote list the electrical ratings. Use those over any rule of thumb.
Try it on your own numbers
This is a planning estimate, not an electrical design. A licensed electrician must confirm your actual panel, wiring and local code requirements before any work. Nothing here is a guarantee of safety or code compliance.