Climate ZonesMontanaLake

Lake, Montana HVAC Climate Zone

Lake is located in IECC Climate Zone 6B (Cold - Dry). Get accurate Manual J load calculations with official design temperatures for Lake.

Climate Zone
6B
Winter Design
-13°F
Summer Design
91°F
ZIP Codes
11

Lake HVAC Contractors: Get Your Free Manual J Report

Climate Zone 6B requires precise load calculations. Upload your Lake blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Lake's exact design temperatures (-13°F winter / 91°F summer).

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Verify Your Lake ZIP Code

Enter your ZIP code to confirm it's in Lake and get climate zone details.

Lake covers 11 ZIP codes: 59821, 59824, 59855, 59860, 59864, 59865, 59910, 59914, 59915, 59929 and 1 more

Lake Design Temperatures

Official ASHRAE design temperatures for Lake, used for accurate Manual J load calculations.

Winter 99% Design Temp
-13°F
Summer 1% Design Temp
91°F
Summer Wet Bulb
62°F

IECC Requirements for Zone 6B

Minimum insulation and window requirements for Lake per IECC 2021.

Wall Insulation:R-20
Roof/Ceiling:R-49
Floor Insulation:R-30
Window U-Factor:0.3
Window SHGC:0.4

Energy Code: 2021 IECC

Recommended HVAC Equipment for Lake

Heating Systems

Gas furnace (96%+ AFUE)
Boiler
Typical AFUE
96-98%

Cooling Systems

AC (13-14 SEER, often optional)
Typical SEER
13-14 SEER

Related Climate Zone Pages

Learn More About
Climate Zone 6B
View All Zones in
Montana
HVAC Permits for
Lake, Montana

Get Free Manual J Calculations for Lake

Upload your Lake blueprint and get a professional Manual J load calculation using official Zone 6B design temperatures. First report is FREE.

Lake design temps
Zone 6B compliant
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