What Climate Zone is Floyd, Kentucky?

Floyd is in IECC Climate Zone 4A (Mixed - Humid). Get accurate Manual J load calculations with official design temperatures for Floyd.

Climate Zone
4A
Winter Design
13°F
Summer Design
91°F
ZIP Codes
33

Floyd, Kentucky falls within IECC Climate Zone 4A (Mixed - Humid), a mixed-climate region with humid moisture conditions. HVAC contractors working in Floyd must use the official ASHRAE design temperatures of 13°F (99% winter) and 91°F (1% summer) when performing Manual J load calculations. These values represent the outdoor conditions your heating and cooling system must handle 99% and 1% of the year, respectively — ensuring proper equipment sizing without costly over- or under-sizing.

Zone 4A experiences both significant heating and cooling loads. Floyd homes need balanced insulation — R-20 walls, R-49 ceilings — plus windows with U-factor 0.32 and SHGC 0.4 per the IECC 2021 energy code.

Floyd Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance requirements for Climate Zone 4A in Floyd, Kentucky.

Building ComponentMinimum RequirementUnit
Ceiling / Attic InsulationR-49R-value
Wall InsulationR-20R-value
Floor InsulationR-19R-value
Window U-Factor0.32BTU/hr-ft²-°F
Window SHGC0.4Coefficient
Air Infiltration0.15ACH50

Floyd HVAC Contractors: Get Your Free Manual J Report

Climate Zone 4A requires precise load calculations. Upload your Floyd blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Floyd's exact design temperatures (13°F winter / 91°F summer).

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Verify Your Floyd ZIP Code

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

Floyd covers 33 ZIP codes: 41216, 41601, 41602, 41603, 41604, 41605, 41606, 41607, 41612, 41615 and 23 more

Floyd Design Temperatures

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

Winter 99% Design Temp
13°F
Summer 1% Design Temp
91°F
Summer Wet Bulb
75°F

IECC Requirements for Zone 4A

Minimum insulation and window requirements for Floyd 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 Floyd

Heating Systems

Gas furnace (90%+ AFUE)
Heat pump
Typical AFUE
92-96%

Cooling Systems

AC (14-16 SEER)
Heat pump
Typical SEER
14-16 SEER

Get Free Manual J Calculations for Floyd

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Floyd design temps
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