Climate Zone 8 - Subarctic
Cool summers and extremely cold winters. Heating only climate. This climate zone encompasses parts of Alaska and includes major cities like Fairbanks, Anchorage, Barrow.
Common Questions About Zone 8
Zone 8 definition
This page explains what IECC climate zone 8 means in HVAC and building-code terms.
Cities in zone 8
Use the city examples below to answer common lookup searches for this zone.
Heating and cooling profile
See whether zone 8 is heating-dominant, cooling-dominant, or balanced.
HVAC requirements
Compare design temperatures, degree days, code requirements, and equipment guidance for this zone.
What IECC Climate Zone 8 Means
Temperature class
Subarctic (Zone 8)
Moisture class
Variable
Load priority
Heating-dominant
Quick definition
Cool summers and extremely cold winters. Heating only climate.
Common City Lookups for Zone 8
| City | IECC zone answer | Why it matters |
|---|---|---|
| Fairbanks | Fairbanks is commonly treated as IECC climate zone 8 in this guide. | Extreme heating loads only |
| Anchorage | Anchorage is commonly treated as IECC climate zone 8 in this guide. | Extreme heating loads only |
| Barrow | Barrow is commonly treated as IECC climate zone 8 in this guide. | Extreme heating loads only |
Design Temperatures
Winter Design Temperatures
Used for heating load calculations and equipment sizing
Summer Design Temperatures
Used for cooling load calculations and equipment sizing
Heating & Cooling Degree Days
Heating Degree Days (HDD)
Base 65°F. Higher numbers indicate more heating requirements and longer heating seasons.
Cooling Degree Days (CDD)
Base 65°F. Higher numbers indicate more cooling requirements and longer cooling seasons.
HVAC System Considerations
Key Considerations
- •Extreme heating loads only
- •No cooling equipment needed
- •Permafrost considerations
- •Equipment designed for extreme cold
- •Multiple backup systems required
Common Equipment
- ✓High-efficiency oil/gas furnaces
- ✓Boilers
- ✓Electric resistance heating
- ✓Wood/coal backup systems
Energy Code Requirements
Equipment Efficiency
- ⚠Maximum efficiency equipment required
- ⚠Superior building envelope
- ⚠Continuous insulation mandatory
- ⚠Extreme air sealing requirements
Insulation Requirements
States with Zone 8 Areas
Quick Reference
Calculate Load
Use our load calculators with the design temperatures and requirements specific to Zone 8.