Climate ZonesIowaIowa

Iowa, Iowa HVAC Climate Zone

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

Climate Zone
5A
Winter Design
0°F
Summer Design
91°F
ZIP Codes
12

Iowa HVAC Contractors: Get Your Free Manual J Report

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

Claim Free Report
No credit card required

Verify Your Iowa ZIP Code

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

Iowa covers 12 ZIP codes: 52203, 52220, 52236, 52251, 52301, 52307, 52308, 52316, 52325, 52334 and 2 more

Iowa Design Temperatures

Official ASHRAE design temperatures for Iowa, 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 Iowa 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 Iowa

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
Iowa
HVAC Permits for
Iowa, Iowa

Get Free Manual J Calculations for Iowa

Upload your Iowa blueprint and get a professional Manual J load calculation using official Zone 5A design temperatures. First report is FREE.

Iowa design temps
Zone 5A compliant
Ready in 60 seconds
Upload Blueprint → Get Free Report

Join 10,000+ Iowa contractors who trust AutoHVAC