AC Installation in Ottawa, IL
A new air conditioner in Ottawa will run from June through August every year. Tell us about the house, and a licensed contractor who covers LaSalle County will get in touch.
Tell us about the job
It takes about a minute.
Three months of real heat, and hail to plan around
Ottawa's cooling season runs June through August, three months a year, with summer afternoons averaging 83°F. A new air conditioner has to be sized to handle those months, not sit oversized and idle the rest of the year.
What sits outside matters too. Ottawa has logged 39 hail events and 124 damaging wind events over the past ten years, with hail as large as 3.75 inches. An outdoor condenser has to stand up to that. And if this is a new install, it needs to meet the federal minimum of 13.4 SEER2, the efficiency baseline for new central air conditioners built since 2023.
- 3 months
- June through August, your air conditioner is on duty
- 83°F
- the average summer afternoon it cools against
- 39 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
A higher-efficiency unit would save about $30 a year to run in LaSalle County compared with a new unit at the federal minimum.
Estimates for a typical LaSalle County home, from EIA household energy data, Illinois fuel prices and NOAA climate normals. Your home will differ.
In Illinois, HVAC licensing for homes is left to the cities and towns.
Illinois does not run a state HVAC license. Whether a contractor needs one comes down to the city or town, because that is where the rule is set instead. There is no single answer for LaSalle County. It depends on what the local government where the house sits requires.
For an air conditioner installation, what usually stands behind the work is a permit rather than a license. In most cities and counties here, installing an air conditioner needs a permit from the local building office. It also gets an inspection once the work is done. That inspection is what checks the job in place of a state license.
Source: Illinois General Assembly
- What size air conditioner does my house need?
- There's no single number that fits every house. A contractor works this out from your square footage, how many windows you have and which way they face, your insulation, and your ceiling height. An oversized unit cools the air fast but shuts off before it pulls the humidity out, so the house feels clammy. An undersized one runs constantly and still can't keep up on the hottest afternoons. A contractor will run a load calculation on your actual house before recommending a size.
- Should I replace the whole system or just the outdoor unit?
- In most cases you want to replace both the outdoor unit and the indoor coil together. They're matched to work at a specific capacity and efficiency, and pairing a new outdoor unit with an old coil can mean the system never hits the performance it's rated for. It can also void the manufacturer's warranty on the new equipment. A contractor can look at the age and condition of your coil and tell you whether it's a candidate to keep.
- Do HVAC contractors in Ottawa need a state license to work on my home?
- Illinois leaves HVAC licensing to individual cities and towns rather than requiring one statewide license. That means the rule depends on where you live, so check with your city to see whether it requires HVAC contractors to be licensed there.