What HVAC Costs in Fairfield County
Heating and cooling work in Fairfield County runs 15-25% above national averages. Connecticut requires contractor licenses (S-1 through S-10 categories) for all HVAC work, and the combination of old housing stock, cold winters, and humid summers means most homes need both heating and cooling systems.
The big story in Fairfield County HVAC right now is heat pumps. Connecticut's Energize CT program offers some of the most generous heat pump rebates in the country, up to $15,000 for whole-home heat pump systems. That's changing the math on what homeowners choose to install.
2026 HVAC Costs in Fairfield County
These numbers are from HVAC contractors working across the county. Equipment brand and home size cause the biggest swings.
| Job | Low | High | Notes |
|---|---|---|---|
| Central AC installation (3-ton) | $5,000 | $11,000 | CT S-license required |
| Furnace replacement (gas, 80-96% AFUE) | $4,200 | $8,500 | Eversource/UI rebates for high-efficiency |
| Heat pump, ducted air-source | $5,500 | $11,000 | Energize CT rebates up to $15,000 for whole-home |
| Ductless mini-split (single zone) | $2,800 | $5,500 | Rebates can cover $1,000-3,000 |
| Full HVAC system (furnace + AC) | $11,000 | $20,000 | Replacing both at once recommended for efficiency |
| Boiler replacement (gas or oil) | $4,800 | $11,000 | Oil-to-gas conversion trending across county |
Town-by-Town Pricing
Greenwich HVAC work is the most expensive in the county. Larger homes need bigger systems, and many Greenwich properties have zoned heating and cooling that requires more equipment and labor. A full HVAC replacement in a 3,500 sq ft Greenwich colonial can exceed $25,000.
Stamford and Norwalk are mid-range. The housing mix keeps averages reasonable, and there's strong competition among HVAC companies in the I-95 corridor.
Danbury tends to be 10-15% cheaper than the coastal towns, but oil heat is more common inland. Many Danbury homes still run on oil boilers, and the conversion to gas or heat pumps is a major expense ($8,000-15,000) that coastal towns with gas infrastructure dealt with years ago.
Fairfield and Westport are in the upper-middle range. Older homes in both towns frequently have outdated heating systems that need full replacement rather than repair.
The Heat Pump Opportunity in CT
Connecticut's Energize CT program offers up to $15,000 in rebates for whole-home heat pump installations. Single-zone mini-splits qualify for $1,000-3,000 back. These rebates are administered through Eversource and United Illuminating and can be combined with federal tax credits (up to $2,000 for heat pumps under the Inflation Reduction Act). A $11,000 heat pump system could net out to $5,000-7,000 after all incentives. Check energizect.com for current rebate amounts and qualifying equipment.
Oil Heat Conversions
A significant number of Fairfield County homes, especially in inland towns like Danbury, Brookfield, and New Fairfield, still run on oil heat. Oil prices fluctuate more than natural gas, and oil systems are generally less efficient.
Converting from oil to gas costs $8,000-15,000 if gas is available at the street. The conversion includes removing the oil tank ($1,000-3,000 depending on whether it's above or below ground), installing a gas line from the street, and replacing the boiler or furnace.
If gas isn't available, heat pumps are the alternative. Cold-climate heat pumps now work efficiently down to -15F, which covers every winter day in Fairfield County. The Energize CT rebates make heat pumps competitive with gas conversions on upfront cost, and operating costs are typically lower.
Permits and Licensing
All HVAC installations and replacements require permits in Connecticut. Your contractor needs a state HVAC license (S-1 through S-10 categories) and HIC registration. The permit covers the installation and requires a follow-up inspection. Stamford: (203) 977-4164. Norwalk: (203) 854-7755. Danbury: (203) 797-4580. Greenwich: (203) 622-7754. Fairfield: (203) 256-3036.
The Bottom Line
Budget $11,000-20,000 for a full HVAC system replacement. Before choosing equipment, check Energize CT rebates and federal tax credits. Heat pumps with full incentives can cost less than traditional systems. Get three quotes from CT-licensed HVAC contractors. Compare HVAC contractors in your area through our Fairfield County HVAC directory.
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Alex Colombo is the founder of Westchester AI, a technology consulting firm serving businesses across Westchester County and the tri-state area. When he's not helping local companies modernize their operations, he's researching what home improvement actually costs in the area so homeowners don't walk into quotes blind.