Climate ZonesOregonDouglas

Douglas, Oregon HVAC Climate Zone

Douglas is located in IECC Climate Zone 4C (Mixed - Marine). Get accurate Manual J load calculations with official design temperatures for Douglas.

Climate Zone
4C
Winter Design
29°F
Summer Design
85°F
ZIP Codes
23

Douglas HVAC Contractors: Get Your Free Manual J Report

Climate Zone 4C requires precise load calculations. Upload your Douglas blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Douglas's exact design temperatures (29°F winter / 85°F summer).

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Verify Your Douglas ZIP Code

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

Douglas covers 23 ZIP codes: 97410, 97416, 97417, 97428, 97429, 97435, 97436, 97441, 97442, 97443 and 13 more

Douglas Design Temperatures

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

Winter 99% Design Temp
29°F
Summer 1% Design Temp
85°F
Summer Wet Bulb
67°F

IECC Requirements for Zone 4C

Minimum insulation and window requirements for Douglas per IECC 2021.

Wall Insulation:R-20
Roof/Ceiling:R-49
Floor Insulation:R-19
Window U-Factor:0.32
Window SHGC:0.4

Energy Code: 2021 IECC

Recommended HVAC Equipment for Douglas

Heating Systems

Gas furnace
Heat pump
Typical AFUE
92-95%

Cooling Systems

AC (optional)
Heat pump
Typical SEER
14 SEER

Related Climate Zone Pages

Learn More About
Climate Zone 4C
View All Zones in
Oregon
HVAC Permits for
Douglas, Oregon

Get Free Manual J Calculations for Douglas

Upload your Douglas blueprint and get a professional Manual J load calculation using official Zone 4C design temperatures. First report is FREE.

Douglas design temps
Zone 4C compliant
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