Washington spans 2 IECC climate zones. Find your exact zone, design temperatures, and get free Manual J load calculations for any Washington location.
Mixed - Marine
Cool - Dry
Based on Climate Zone 4C (Mixed - Marine), here are typical HVAC equipment specifications for Washington installations.
Annual Fuel Utilization Efficiency for Washington furnaces
Seasonal Energy Efficiency Ratio for Washington AC systems
Washington's climate zone data ensures proper equipment sizing. No more callbacks from oversized or undersized systems.
Washington building departments require IECC-compliant Manual J calculations. Our tool uses official Washington climate data.
Right-sized systems based on Washington climate data reduce energy costs for homeowners and improve your reputation.
Upload your Washington blueprint and get a professional Manual J load calculation with official climate zone data. First report is FREE.
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Get detailed climate zone information for major cities
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