Climate ZonesMichiganWashtenaw

Washtenaw, Michigan HVAC Climate Zone

Washtenaw is located in IECC Climate Zone 5A (Cool - Humid). Get accurate Manual J load calculations with official design temperatures for Washtenaw.

Climate Zone
5A
Winter Design
0°F
Summer Design
91°F
ZIP Codes
15

Washtenaw HVAC Contractors: Get Your Free Manual J Report

Climate Zone 5A requires precise load calculations. Upload your Washtenaw blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Washtenaw's exact design temperatures (0°F winter / 91°F summer).

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Verify Your Washtenaw ZIP Code

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

Washtenaw covers 15 ZIP codes: 48103, 48104, 48105, 48108, 48109, 48118, 48130, 48158, 48160, 48176 and 5 more

Washtenaw Design Temperatures

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

Winter 99% Design Temp
0°F
Summer 1% Design Temp
91°F
Summer Wet Bulb
75°F

IECC Requirements for Zone 5A

Minimum insulation and window requirements for Washtenaw 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: 2020 IECC

Recommended HVAC Equipment for Washtenaw

Heating Systems

Gas furnace (95%+ AFUE)
Boiler
Heat pump (cold climate)
Typical AFUE
95-98%

Cooling Systems

AC (13-16 SEER)
Heat pump
Typical SEER
13-16 SEER

Related Climate Zone Pages

Learn More About
Climate Zone 5A
View All Zones in
Michigan
HVAC Permits for
Washtenaw, Michigan

Get Free Manual J Calculations for Washtenaw

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Washtenaw design temps
Zone 5A compliant
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