Find HVAC designers anywhere in Illinois: we cover 1,294 cities and towns, home to 11,096,576 people. Pick your city below or describe your project right away: up to three local pros get back to you, free and with no obligation.
Every pro you are matched with in Illinois declares the license or certification required for this work.
Services available in Illinois
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Manual J load calculation
Room-by-room heating and cooling load calculation for the HVAC permit.
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Manual S and D equipment and duct design
Equipment selection and duct design from the load calculation.
Frequently asked questions in Illinois
Do you cover all of Illinois?
Yes. Requests can come from any of the 1,294 cities and towns of Illinois, and from unincorporated areas: just enter your ZIP code.
Is the service free?
Yes, for you. The HVAC designers pay to receive requests; you pay only the one you choose to hire, if any.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.