AC Installation in Dover, NH
A new air conditioner in Dover will run from July through August every year. Tell us about the house, and a licensed contractor who covers Strafford County will get in touch.
Tell us about the job
It takes about a minute.
Two months of real heat, and a season that can turn rough
Dover only asks for cooling in July and August, with afternoons averaging 79°F. That is a short season, but the unit still has to be sized and installed right to keep up on the hottest days it does get.
Strafford County has seen its share of rough weather too, with 43 damaging wind events and 9 hail storms over the past ten years, one dropping hail 2.5 inches across. Any new system going in outside needs to handle that, not just the heat. If your unit was built in 2023 or later, it has to meet a federal minimum of 13.4 SEER2, so a proper install matters as much as the equipment itself.
- 2 months
- July through August, your air conditioner is on duty
- 79°F
- the average summer afternoon it cools against
- 9 hail events
- in ten years, and hail bends the fins on outdoor coils
- 13.4 SEER2
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
Going above the federal minimum saves little here, about $20 a year.
Estimates for a typical Strafford County home, from EIA household energy data, New Hampshire fuel prices and NOAA climate normals. Your home will differ.
New Hampshire has no state license for HVAC contractors.
There is no state record to check here. New Hampshire does not test HVAC contractors, and it keeps no list of registered ones either. Anyone can call themselves an HVAC contractor and take on this job, and the state will have no file on them one way or the other.
Most cities and counties require a permit for an installation like this one, along with an inspection once the work is done, and that is likely true in Strafford County as well. That inspection is what checks the job here, not a license, because there is no license in this state to do it.
Source: New Hampshire General Court
- What size air conditioner does my house need?
- The right size comes from a load calculation, not a rule of thumb based on square footage alone. A contractor measures your windows, insulation, ceiling height and how much shade your house gets, then runs those numbers to find the tonnage you need. Too big and it cools the air fast but never pulls the humidity down, so the house feels clammy. Too small and it runs constantly on those 79°F afternoons and still can't keep up. Ask whoever quotes the job to show you the calculation, not just a guess.
- Should I replace the whole system or just the outdoor unit?
- If your indoor coil and outdoor unit are different ages or from different manufacturers, matching just the outdoor unit can leave you with a mismatched system that never reaches its rated efficiency. New central air conditioners have to meet 13.4 SEER2 now, and hitting that number usually depends on the indoor coil and outdoor unit working as the pair they were designed to be. A contractor can check your existing coil and tell you whether it will perform with a new outdoor unit or whether replacing both is the better route.
- Do HVAC contractors in Dover need a state license to work on my home?
- No. New Hampshire has no state license or registration for HVAC contractors. That puts more weight on checking a contractor's own credentials, insurance and track record yourself before hiring one. You will still need a permit from the local building office for an air conditioner installation, along with an inspection once the work is done.