Kootenai County is in IECC Climate Zone 5B (Cool - Dry). Get accurate Manual J load calculations with official ASHRAE design temperatures for Kootenai County.
Kootenai County, Idaho is classified under IECC Climate Zone 5B (Cool - Dry), a heating-dominated region with dry moisture conditions. With 14 ZIP codes and 1 communities, every HVAC installation in Kootenai County must use the ASHRAE design temperatures of 8°F (99% winter heating) and 91°F (1% summer cooling) for accurate Manual J load calculations.
As a heating-dominated zone, Kootenai County requires robust insulation — a minimum of R-20 in walls, R-49 in ceilings, and R-30 in floors. Windows must meet a U-factor of 0.3 or lower. These requirements ensure homes maintain comfort during the coldest 8°F design conditions.
Minimum insulation R-values and window performance for Climate Zone 5B in Kootenai County, ID.
| Building Component | Minimum Requirement | Unit |
|---|---|---|
| Ceiling / Attic Insulation | R-49 | R-value |
| Wall Insulation | R-20 | R-value |
| Floor Insulation | R-30 | R-value |
| Window U-Factor | 0.3 | BTU/hr-ft²-°F |
| Window SHGC | 0.4 | Coefficient |
| Air Infiltration | 0.15 | ACH50 |
Climate Zone 5B requires precise load calculations. Upload your Kootenai County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Kootenai County's exact design temperatures (8°F winter / 91°F summer).
Enter your ZIP code to confirm it's in Kootenai County and get climate zone details.
Official ASHRAE design temperatures for Kootenai County, ID, used for accurate Manual J load calculations.
Minimum insulation and window requirements for Kootenai County per IECC 2021 energy code.
Climate Zone 5B: Cool - Dry - Heating-dominated with cold, dry winters and warm summers. High heating loads in winter, moderate cooling needs.
1 cities and communities in Kootenai County share Climate Zone 5B requirements.
Compare climate zones with other counties in Idaho. Different zones require different HVAC equipment sizing.
Upload your Kootenai County blueprint and get a professional Manual J load calculation using official Zone 5B design temperatures. First report is FREE.
Join 10,000+ Idaho contractors who trust AutoHVAC