Allentown, Pennsylvania HVAC Climate Zone

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

Climate Zone
5A
Winter Design
0°F
Summer Design
91°F
ZIP Codes
7

Allentown HVAC Contractors: Get Your Free Manual J Report

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

Claim Free Report
No credit card required

Verify Your Allentown ZIP Code

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

Allentown covers 7 ZIP codes: 18101, 18102, 18103, 18104, 18105, 18106, 18109

Allentown Design Temperatures

Official ASHRAE design temperatures for Allentown, 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 Allentown 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 Allentown

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

Get Free Manual J Calculations for Allentown

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

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

Join 10,000+ Allentown contractors who trust AutoHVAC