AC Installation in Rochester, MN
A new air conditioner in Rochester will run from June through August every year. Tell us about the house, and a licensed contractor who covers Olmsted County will get in touch.
Tell us about the job
It takes about a minute.
Three months of heat, a lot more of storms
Rochester only asks a new air conditioner to work June through August, three months a year. Summer afternoons here average 79°F, so the unit needs to be sized to handle that heat, not more.
The rest of the year, that outdoor unit just sits there exposed. Olmsted County has logged 91 hail events and 92 damaging wind events over the past ten years, with hail up to 2 inches. A new system needs to hold up to that as much as it needs to cool the house. Any central air conditioner installed now also has to meet the federal efficiency minimum of 13.4 SEER2.
- 3 months
- June through August, your air conditioner is on duty
- 79°F
- the average summer afternoon it cools against
- 91 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 Olmsted County home, from EIA household energy data, Minnesota fuel prices and NOAA climate normals. Your home will differ.
Minnesota has no state license for HVAC contractors.
Minnesota does not put HVAC contractors through a state test or keep a record of them. There is no license number to check and no registration on file with the state. Whatever protection exists here comes from somewhere else.
For an air conditioner installation, that somewhere else is the local building office. Most cities and counties in Minnesota require a permit for this job, and an inspection once the work is done. The inspector is checking that the installation was done to code, which is the closest thing to independent oversight this job gets in Olmsted County.
Source: Minnesota Office of the Revisor of Statutes
- What size air conditioner does my house need?
- There is no single number that fits every house. The right size depends on your square footage, how many windows you have, how much insulation is in your walls and attic, and which way your house faces. A contractor works this out with a load calculation, not a guess based on your old unit's tonnage. Going too big is as much a problem as going too small, since an oversized unit cools the air fast but shuts off before it pulls the moisture out, leaving the house feeling damp.
- Should I replace the whole system or just the outdoor unit?
- If your indoor coil and outdoor unit were installed together and matched to each other, replacing only the outdoor unit can leave you with a mismatch that hurts efficiency and can shorten the life of the new unit. New central air units sold today have to meet a federal minimum of 13.4 SEER2, and an old indoor coil often was not built to work with that. A contractor can check whether your existing coil and ductwork will pair with a new outdoor unit or whether the job needs to be done as a full system.
- Do HVAC contractors in Rochester need a state license to work on my home?
- No. Minnesota has no state license or registration for HVAC contractors doing home work. That does not mean there is no oversight on the job itself. Installing an air conditioner in most cities and counties still needs a permit from the local building office, along with an inspection once the work is finished.