What size heat pump do I need for a 3,000 sq ft house?

About 4 tons to more than 5 tons. In a mixed climate like Atlanta the estimate is 5 tons (cooling load 44,700 BTU/h, heating load 57,000 BTU/h). Hot climates need more cooling capacity and cold climates more heating capacity, as the table shows.

How many BTU do I need for 3,000 square feet?

For cooling, roughly 48,900 BTU/h in a hot, dry climate and 38,400 BTU/h in a cold one. For heating, from 45,000 to 90,000 BTU/h depending on how cold winters get. Older, drafty homes need up to 30% more.

Is it better to oversize or undersize a heat pump?

Neither, but slight undersizing is usually less harmful for cooling. An oversized unit short-cycles and leaves the air clammy. In cold climates, size for the heating load and check the unit’s output at 5°F, or plan for backup heat on the coldest nights.

What size heat pump for a 3,000 sq ft house?

Short answer: 4 tons to more than 5 tons, depending on your climate and insulation. In a mixed climate like Atlanta: 5 tons.

By climate

Hot and dry (Phoenix)4 ton
Hot and humid (Houston)4 ton
Mixed (Atlanta)5 ton
Cold (Chicago)5+ ton
Very cold (Minneapolis)5+ ton

Average insulation, 8 ft ceilings, three occupants.

Best 5-ton heat pumps

Most efficient

Lennox SL22KLV-060-230A

5 ton central · DAVE LENNOX SIGNATURE SL22KLV SERIES · cold-climate certified

SEER2: 21.1
HSPF2: 9.6
Heat at 5°F: 45,500

Top-rated certified model in the size most 3,000 sq ft homes need.

Full specs and running cost

Best for cold winters

Fujitsu FOP1560TJAZNA

5 ton central · F Series · cold-climate certified

SEER2: 16.0
HSPF2: 8.1
COP at 5°F: 2.60

Cold-climate certified, best efficiency at 5°F in this size.

Full specs and running cost

Compare all 5-ton heat pumps

Work it out for your home

Pre-filled with 3,000 sq ft. Pick your city and adjust insulation, sun and ceiling height.

Your space

Area to heat and cool sq ftCeiling heightInsulationSun exposurePeople who usually use itIncludes the kitchen?

Your climate

StateCity

Mini-split size: 48,000 BTU
Central / ducted size: 4 ton
Cooling load: 48,900 BTU/h
Heating load: 45,000 BTU/h

This is more than one indoor unit can handle well - look at multi-zone systems or a ducted central heat pump.

See 48,000 BTU mini-splits See 4-ton central heat pumps

Rule-of-thumb estimate: cooling follows the ENERGY STAR room sizing table, heating uses typical BTU per square foot for the climate (NOAA 1991-2020 heating degree days). For a whole-house system, ask your installer for a Manual J load calculation.

More detail

Cooling and heating loads by climateBTU/h

Hot and dry (Phoenix)cooling 48,900 · heating 45,000
Hot and humid (Houston)cooling 48,900 · heating 45,000
Mixed (Atlanta)cooling 44,700 · heating 57,000
Cold (Chicago)cooling 42,600 · heating 81,000
Very cold (Minneapolis)cooling 38,400 · heating 90,000

Cooling follows the ENERGY STAR sizing table; heating uses BTU per sq ft for the climate (NOAA 1991-2020 normals).

How insulation changes the sizein Atlanta

Poor5+ ton · heating 74,100 BTU/h
Average5 ton · heating 57,000 BTU/h
Good4 ton · heating 45,600 BTU/h
Very good3.5 ton · heating 37,100 BTU/h

Top 5 5-ton heat pumpsranked by SEER2

#	Model	SEER2	EER2	HSPF2	COP at 5°F
1	Lennox SL22KLV-060-230A	21.1	11.7	9.6	2.04
2	Lennox EL21KLV-060-230A	20.5	11.7	9.0	2.18
3	GE NS21H60MA5-**A	20.5	11.7	8.5	2.16
4	ACIQ B5H0V60KAAA	20.0	10.0	9.0	2.12
5	Tempstar B5H3V60KAAA	20.0	12.5	9.0	2.18

Questions3

What size heat pump do I need for a 3,000 sq ft house?: About 4 tons to more than 5 tons. In a mixed climate like Atlanta the estimate is 5 tons (cooling load 44,700 BTU/h, heating load 57,000 BTU/h). Hot climates need more cooling capacity and cold climates more heating capacity, as the table shows.
How many BTU do I need for 3,000 square feet?: For cooling, roughly 48,900 BTU/h in a hot, dry climate and 38,400 BTU/h in a cold one. For heating, from 45,000 to 90,000 BTU/h depending on how cold winters get. Older, drafty homes need up to 30% more.
Is it better to oversize or undersize a heat pump?: Neither, but slight undersizing is usually less harmful for cooling. An oversized unit short-cycles and leaves the air clammy. In cold climates, size for the heating load and check the unit’s output at 5°F, or plan for backup heat on the coldest nights.

Other sizes

All sizing guides