What size heat pump for 1,100 sq ft in Arizona?2.5 tons nominal
See cooling demand and winter heating demand separately, including a cold-weather capacity assumption.
Your starting point
2.5 tons nominal
Planning range
1.5–3 tons
A screening estimate under the assumptions below. The range is a shopping guide, not a guarantee.
Planning estimate. A licensed contractor must confirm the final size, installation and local code requirements. Electrical work needs a licensed electrician.
Adjust your home
The calculation, step by step.
Larger of cooling load and heating output / assumed winter retention; round upward in half-ton steps.
| Input or step | Calculated amount |
|---|---|
| Heated floor area | 1,100 sq ft |
| Screening coefficient | 25 BTU/h per sq ft |
| Estimated heating output | 27,500 BTU/h |
| Cooling load | 26,400 BTU/h |
| Assumed winter capacity retained | 100% |
| Heating-led nominal capacity | 27,500 BTU/h |
What moves this number?
Winter performance
Check the actual unit capacity at your design temperature.
Heating load
The colder the climate or leakier the envelope, the more heating output you need.
Summer comfort
Check minimum cooling output and humidity control before selecting a heating-led size.
Your location and assumptions.
Maricopa, Arizona is IECC 2021 zone 2B. The zone selects a regional screening coefficient. A professional calculation uses local design temperatures and the actual building envelope. Other counties in this state can have a different zone. Local code adoption may use another edition.
- Zone 2B is a regional indicator, not a design temperature.
- Central heating coefficients and +/-20% range are SizeMyUnit screening assumptions.
- 8 ft ceilings; average insulation.
What might it cost to run?
Illustrative heating electricity: 2.69 kW, or $0.40/hour, at an assumed COP of 3. Cold weather, defrost and resistance backup change it. Uses the published 2024 EIA Arizona residential average of $0.1491/kWh, not your current tariff.
Before you choose equipment.
A contractor must calculate room-by-room heat loss at the local winter design temperature. Nameplate input and delivered output are different.
A heating-led size may oversize summer cooling. Ask about variable capacity, balance temperature and backup heat. Retention is a user-adjustable assumption, not a tested claim about any model.
Bring this calculation to your installer. They will check the measured load, manufacturer performance, distribution or connections, installation conditions and local requirements.
A few more sizing questions.
What size heat pump for 1,100 square feet?
The default screen gives 2.5 tons nominal, with a planning range of 1.5–3 tons. Change the inputs above to reflect your actual home. Heating and cooling loads are shown separately in the calculation.
Why is the heat-pump size larger than the AC size?
Winter heat loss may dominate. This model divides heating output by the selected 100% capacity retention and compares it with cooling demand.
Does every heat pump lose the same capacity in winter?
No. The retention input is an assumption, not a product test. Check the actual capacity curve at your winter design temperature, including defrost and backup heat.
Will a heating-led size cause summer problems?
It can. Ask the contractor to check minimum output, modulation, humidity control and the balance between heat-pump capacity and backup heat.
Can a mini-split replace a furnace?
Some systems can cover the measured winter load; others require backup heat. Indoor zone distribution, cold-weather performance and electrical capacity must be checked separately.
Is this a final equipment size?
No. A licensed contractor must measure your building or actual loads, check manufacturer performance and local code, and confirm the final selection.