Across 109 permits filed since 2025-01-25, the median is $15,000; half of projects fall between $8,370 and $21,221. Figures are permit valuations reported to building departments. National cost guides answer this question with averages from other markets; these numbers are what homeowners in Middlesex County, CT actually reported when they pulled permits.
Recent filings
- Installation of a central air system, single zone including 40,000 btv gas furnace.HADDAM · 2026-07-23$18,000
- Installation of Aux Ductless single zone heat pump. Indoor unit going in the living area and the home outdoor units going in the back of the home.HADDAM · 2026-07-15$8,370
- Install ductless heat pump system (1) outdoor unit located south side of home.HIGGANUM · 2026-07-15$34,024
How to read these numbers
Permit valuations are the project cost the applicant reports to the building department. They skew slightly low — nobody rounds up for the permit fee — and scope varies, so the middle-half range is the honest picture: half of all hvac / central air permits in Middlesex County, CT came in between $8,370 and $21,221. We exclude permits under $1,000, jobs filed as whole-house construction, and counties whose building departments don't reliably report valuations.
Same project, other places
HVAC / central air in New JerseyHVAC / central air in New YorkHVAC / central air in ConnecticutHVAC / central air on Long Island