Illinois HVAC Load Calculation Guide

Free HVAC load calculation guide for Illinois. Review climate zones, design temperatures, building code context, and local calculator resources for Chicago, Aurora, Rockfordand 2 more cities.

Start with the Free Illinois Load Calculator

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

Illinois Design Temperatures

Winter Design Temperature

-8°F

Used for heating load calculations and equipment sizing across Illinois

Summer Design Temperature

91°F

Used for cooling load calculations and equipment sizing across Illinois

Climate Zone Information

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

Illinois Building Codes & Requirements

HVAC Requirements

  • High-efficiency equipment
  • Duct testing mandatory
  • Ventilation requirements

Note: Chicago has additional green building requirements

Energy Code

2018 IECC with Illinois amendments

Common Building Types

  • Urban apartments
  • Suburban homes
  • Commercial high-rise

Illinois HVAC Challenges

Cold winters

High humidity summers

Urban heat islands

Lake effect weather

Major Cities in Illinois

Aurora
90°F max
Rockford
88°F max
Joliet
89°F max
Springfield
91°F max

Quick Facts

State:Illinois
Abbreviation:IL
Climate Zones:Zone 4A, Zone 5A
Major Cities:5

Local Resources

ComEd

utility

Visit Website →

Illinois Department of Commerce

government

MSCA Chicago

organization