Illinois is in IECC Climate Zone 5A (Cool - Humid). Get accurate Manual J load calculations with official design temperatures and IECC requirements.
Cool - Humid
Based on Climate Zone 5A (Cool - Humid), here are typical HVAC equipment specifications for Illinois installations.
Annual Fuel Utilization Efficiency for Illinois furnaces
Seasonal Energy Efficiency Ratio for Illinois AC systems
Illinois's climate zone data ensures proper equipment sizing. No more callbacks from oversized or undersized systems.
Illinois building departments require IECC-compliant Manual J calculations. Our tool uses official Illinois climate data.
Right-sized systems based on Illinois climate data reduce energy costs for homeowners and improve your reputation.
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