Illinois HVAC Pros
An outdoor air conditioning condenser unit positioned on a concrete pad next to a blue-sided house, surrounded by green shrubs and flowering hydrangeas at sunset.

AC Installation in Crystal Lake, IL

A new air conditioner in Crystal Lake will run from June through August every year. Tell us about the house, and a licensed contractor who covers McHenry County will get in touch.

Tell us about the job

It takes about a minute.

Step 1 of 3: Equipment
Aerial view of a square outdoor air conditioning condenser unit on a concrete pad beside a house wall with a sliding glass door.

Three months of heat, plus the storms in between

Crystal Lake only needs cooling from June through August, three months a year, with summer afternoons averaging 81°F. A new air conditioner here isn't working year round, but it has to be sized right and running well when those three months hit.

McHenry County also sees its share of hail and wind. Ten years of records show 45 hail events, one hailstone as large as 2.75 inches, and 140 damaging wind events. The outdoor condenser sits exposed to all of that, so where it goes and how it's protected matter. Any new central air conditioner installed today also has to meet the federal efficiency minimum of 13.4 SEER2.

3 months
June through August, your air conditioner is on duty
81°F
the average summer afternoon it cools against
45 hail events
in ten years, and hail bends the fins on outdoor coils
13.4 SEER2
the federal minimum any new unit must meet
Isometric cutaway illustration of a single-story house with a dark shingled roof, showing interior rooms with ductwork and an indoor air handler connected to an outdoor condenser unit beside the building.
Your air conditioner works hardest from June through August.

NOAA nClimDiv, 1991–2020 normals

Overhead view of an outdoor AC condenser unit on a concrete pad next to a house with a dark shingle roof.

Going above the federal minimum saves little here, about $20 a year.

  • A higher-efficiency unit$150 a year
  • A new unit at the federal minimum, 13.4 SEER2$170 a year

Estimates for a typical McHenry 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.

Check whether your city requires a license.

Source: Illinois General Assembly

What size air conditioner does my house need?
It depends on your house, not a simple square footage number. A contractor works this out with a load calculation, which looks at how much square footage you're cooling, how many windows you have and which way they face, how much insulation is in your attic and walls, and your ceiling height. Putting in a unit that's too big cools the air fast but shuts off before it pulls the humidity out, so the house feels clammy. Too small and it runs constantly on the hot afternoons and still can't keep up. A contractor can run the numbers for your specific house.
Should I replace the whole system or just the outdoor unit?
In most cases, if the outdoor unit is failing, the indoor coil should go with it. The two are matched to work together, and pairing a new outdoor unit with an old indoor coil often means the system never runs at the efficiency it's rated for, and sometimes it just won't work right at all. Age matters too. If your indoor coil is old enough that the outdoor unit is failing, the coil is usually not far behind it. A contractor can look at both parts and tell you whether the coil is worth keeping.
Do HVAC contractors in Crystal Lake need a state license to work on my home?
Illinois doesn't license HVAC contractors at the state level for residential work. That's left to individual cities and towns, so whether a license is required depends on Crystal Lake's own rules. Check with the city to see what they require before you hire someone.
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