Heat Pumps by U.S. Climate Zone
DOE Building America climate regions are useful for understanding which HVAC design problems matter most in different parts of the United States.
They do not tell you what tonnage to buy.
The building still needs a load calculation.
DOE's Building America framework includes:
- Hot-Humid
- Hot-Dry
- Mixed-Dry
- Mixed-Humid
- Marine
- Cold
- Very Cold
- Subarctic
Source: DOE Climate Zones
Climate-Zone Heat Pump Priorities
| Climate region | Main heat-pump priorities |
|---|---|
| Hot-Humid | cooling load, latent load, modulation, ducts, SEER2/EER2 |
| Hot-Dry | cooling load, peak sensible capacity, SEER2/EER2 |
| Mixed-Dry | heating + cooling balance, part-load performance |
| Mixed-Humid | heating + cooling + humidity, seasonal balance |
| Marine | mild/moderate heating and cooling, moisture/building specifics |
| Cold | low-temp capacity, COP, HSPF2, backup strategy |
| Very Cold | design-day heating capacity, cold-climate equipment, backup |
| Subarctic | very-low-temp performance, building load, robust backup/system design |
Hot-Humid
DOE describes Hot-Humid regions as areas with high precipitation plus sustained high wet-bulb/humidity conditions.
Source: DOE Climate Zones
Prioritize:
- correct cooling/latent load
- humidity control
- long part-load operation
- duct leakage
- high cooling efficiency
Hot-Dry
Cooling dominates, but moisture removal is less central than in Hot-Humid regions.
Prioritize:
- design cooling load
- peak cooling performance
- SEER2/EER2
- solar loads
- duct location
- electricity rate
Mixed-Humid
DOE's Mixed-Humid category combines meaningful winter heating with humid warm-season conditions.
That makes balanced heat-pump design important.
Prioritize:
- heating and cooling loads
- humidity behavior
- HSPF2 + SEER2
- part-load modulation
- duct leakage
Marine
Marine regions have their own temperature and moisture profile.
Do not simply copy a Hot-Humid or Cold-climate system choice.
Use local design weather and building load.
Cold
Prioritize:
- Cold Climate qualified equipment
- heating load
- 5°F capacity and COP
- design-temperature capacity
- defrost
- outdoor-unit snow strategy
- backup heat
Very Cold and Subarctic
These climates make system design more demanding.
The design should explicitly model:
- low-temperature equipment output
- house heat loss
- backup-heat requirement
- electrical capacity
- extreme-weather resilience
Do not infer that a Cold Climate label alone means one system can carry every home through every design condition.
How Do You Find Your Climate Zone?
Use DOE/Building America guidance to identify your county's climate region. Building America's named regions and the numbered IECC climate zones are different classifications; the DOE-linked lookup uses the 2021 IECC zones.
Source: DOE Building America Climate Guidance
PNNL's county guide relates Building America regions to the 2021 IECC designations. Confirm the applicable code edition locally when using a climate zone for code compliance.
Source: PNNL - Climate Zones by County: Building America and IECC 2021 Updates (2022)
Then use the climate region as context for the Manual J inputs and equipment comparison.
Does Climate Zone Determine Size?
No.
It influences the load.
The building still matters.
A high-performance home and an old leaky home in the same climate zone can require very different capacity.
Does Climate Zone Determine Brand?
No.
Use the climate zone to define the required performance envelope.
Then compare equipment from brands that meet it and installers who can support the system locally.
Compare Heat Pumps for Your Climate Zone
Get local installers to show the design-weather inputs and equipment capacity behind their proposal.
Prepare for installer conversations
Check the design process and compare written scopes, equipment matches, and installed costs.