Washington HVAC Load Calculation Guide

Free HVAC load calculation guide for Washington. Review climate zones, design temperatures, building code context, and local calculator resources for Seattle, Spokane, Tacomaand 3 more cities.

Start with the Free Washington Load Calculator

Use our residential or commercial calculator to estimate loads with Washington-relevant climate conditions in mind.

Washington Design Temperatures

Winter Design Temperature

1°F

Used for heating load calculations and equipment sizing across Washington

Summer Design Temperature

89°F

Used for cooling load calculations and equipment sizing across Washington

Climate Zone Information

Washington spans climate zones Zone 4C, Zone 5B, which means different regions may have varying design requirements. Always verify local design temperatures for your specific project location.

Washington Building Codes & Requirements

HVAC Requirements

  • Very high efficiency standards
  • Duct testing mandatory
  • Advanced ventilation

Note: One of the most stringent energy codes in the nation

Energy Code

2018 Washington State Energy Code

Common Building Types

  • Traditional homes
  • Green buildings
  • High-tech facilities

Washington HVAC Challenges

Marine climate

Seismic requirements

Green building standards

Energy codes

Quick Facts

State:Washington
Abbreviation:WA
Climate Zones:Zone 4C, Zone 5B
Major Cities:6

Local Resources

Puget Sound Energy

utility

Visit Website →

Washington State Department of Commerce

government

Washington HVAC Association

organization