AC Installation in Lewistown, MT
A new air conditioner in Lewistown will run from July through August every year. Tell us about the house, and a licensed contractor who covers Fergus County will get in touch.
Tell us about the job
It takes about a minute.
Two months of real heat is still enough to matter
Lewistown only asks for cooling in July and August, with summer afternoons averaging 79°F. That is a short season, but it is a real one, and a new air conditioner still needs to be sized and installed to handle it without straining.
Fergus County has seen 48 hail events and 147 damaging wind events over the past ten years, with hail up to 2.5 inches. An outdoor unit sits exposed to that, so how it is installed and protected matters as much as the equipment itself. Any new central air conditioner installed since 2023 also has to meet a federal minimum efficiency of 13.4 SEER2.
- 2 months
- July through August, your air conditioner is on duty
- 79°F
- the average summer afternoon it cools against
- 48 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 Fergus County home, from EIA household energy data, Montana fuel prices and NOAA climate normals. Your home will differ.
Montana requires HVAC contractors to hold a state license.
Montana licenses HVAC contractors through the Department of Labor and Industry. The license is tied to the contractor, not issued job by job, and the state keeps that record after the contractor meets its requirements. Work under $2,500 does not need a licensed contractor at all. An air conditioner installation runs well past that.
For this job, the state license is what backs the person doing the work. Most cities and counties also require a permit for an installation like this, with an inspection once the work is done. That inspection is what catches a bad refrigerant line or electrical connection before the system runs for years with it.
Source: Montana Legislature
- What size air conditioner does my house need?
- It depends on your square footage, ceiling height, insulation, window count, and how much shade your house gets, not just the size of the old unit. A contractor works this out with a load calculation. A unit that's too big cools the air fast but never runs long enough to pull the humidity down, and one that's too small runs constantly without keeping up. With only July and August to worry about here, it's still worth getting the sizing right, since an oversized unit wears out faster from short cycling.
- Should I replace the whole system or just the outdoor unit?
- If your indoor coil and outdoor unit are original to each other, replacing just the outdoor unit usually isn't a good idea. The two are matched to work together, and pairing an old coil with a new condenser can mean the system never reaches its rated efficiency. It can also void the warranty on the new part. A contractor can look at both and tell you whether the coil is worth keeping or whether it makes more sense to replace the pair.
- Do HVAC contractors in Lewistown need a state license to work on my home?
- Yes. Montana requires HVAC contractors to hold a state license through the Department of Labor and Industry, and installing an air conditioner falls under that. The license covers the contractor, not any single job, so it's worth asking to see it before work starts. Check with your local building office too, since most places require a permit and an inspection once the work is done.