Air Conditioner Installation in O'Fallon, MO
New Central Air Sized to Your Home and Matched to Your Furnace
Air conditioner installation from On Time Experts Heating, Air & Plumbing replaces your central air with a new system sized to your home, matched to your furnace and indoor coil, and priced upfront before any work begins.
What Is Air Conditioner Installation, and When Do You Need It?
Air conditioner installation is the work of sizing, setting and connecting a new central air system so it cools your home evenly and keeps humidity down. At On Time Experts Heating, Air & Plumbing, that usually means a split system: an outdoor condenser paired with an indoor coil that sits on top of the gas furnace in the basement.
You may want a new system when yours is near the end of its life, needs a major repair such as a compressor (the outdoor pump that moves refrigerant), or still runs on R-22, an older refrigerant that is no longer produced.
What Is Included in Air Conditioner Installation?
A full installation covers the equipment and everything that connects it:
- System sizing: A recommended size based on your home's insulation, windows and layout, not square footage alone.
- Matched equipment: A new outdoor condenser and a matched indoor coil (the part above the furnace that cools the air), checked against your furnace's blower.
- Refrigerant line set: The two copper lines between the units, new or flushed and reused where the manufacturer allows.
- Electrical connections: An electrical disconnect (the shutoff box beside the outdoor unit), plus the correct breaker and wiring.
- Condensate drain: A drain line from the indoor coil to a floor drain or condensate pump.
- Refrigerant recovery: The old refrigerant recovered as EPA rules require.
- Permit and start-up: A permit where required, then start-up testing and a walkthrough.
A heat pump heats as well as cools and can pair with your gas furnace as a dual-fuel setup; our Heat Pump Installation and Repair page covers that option. We install central air in O'Fallon, St. Charles, Creve Coeur and the surrounding area.
After installation, a yearly Air Conditioner Deep Clean and Tune-Up keeps the outdoor coil clean so the new system runs as designed.
Why Is Proper Air Conditioner Installation Important?
Size and matching decide how well a new system cools, how much moisture it removes and how long it lasts.
A System That's Too Big Leaves Rooms Clammy
An air conditioner that's too big for the house cools it fast, shuts off, then starts again a few minutes later. Those short runs don't last long enough to pull much moisture out of the air, so in a humid St. Louis July the rooms feel cool but clammy.
A System That's Too Small Falls Behind
One that's too small runs nonstop on the hottest afternoons and still falls behind. The ACCA Manual J load calculation works out how much heat a home gains through walls, windows, the attic and air leaks, so the size comes from the house rather than a square-footage rule of thumb.
Matched Equipment Reaches Its Rated Efficiency
The condenser and indoor coil are built as a pair, and the furnace blower moves air across that coil. A new condenser on an old coil may not reach its rated efficiency.
What Happens During an Air Conditioner Installation Visit?
Here's how an installation runs:
- Look at your current system. We check the equipment, ductwork and electrical service, and ask what you'd like to change.
- Size and price the options. We work out the size your home needs and lay out system options, with upfront pricing for each.
- Remove the old equipment. On install day, we protect your floors, shut off power and recover the old refrigerant.
- Set and connect the new system. We set the condenser, install the matched coil, and connect the line set, disconnect and condensate drain.
- Test, vacuum and charge. We pressure-test the lines for leaks, pull a vacuum to clear out air and moisture, then charge the system.
- Walk you through it. We check temperatures, airflow and drainage, set up the thermostat and clean up.
You'll know how to run the new system before we leave.
Frequently asked questions
Rebates for air conditioner installation may be available through Ameren Missouri's energy-efficiency programs for qualifying high-efficiency systems.
Amounts and requirements change through the year, so check the current offers before you settle on a model. A technician can point out which systems on your quote may qualify.
SEER2 is the efficiency rating on every new central air conditioner. A higher number means the system uses less electricity for the same cooling over a season, and higher-efficiency systems usually cost more up front.
The "2" marks a newer test that better reflects real ductwork, so SEER2 numbers run a little lower than the old SEER ratings for the same equipment. Two-stage and variable-speed systems can run longer at lower speeds, which helps pull more moisture out of the air.
Most air conditioner installations include a new indoor coil, because the outdoor condenser and the coil are designed as a matched pair. A new condenser on an old coil may not reach its rated efficiency and can wear out sooner.
Under EPA rules phasing down older refrigerants, most new central air systems now use refrigerants such as R-454B or R-32, which need a coil rated for them. A technician will confirm what your system needs and include it in the upfront price.
The right size for an air conditioner installation comes from a load calculation, not square footage alone. The ACCA Manual J method accounts for insulation, windows, sun exposure, air leaks and the number of people living in the home.
Two homes with the same square footage can need different sizes. A properly sized system runs long enough to control humidity and keeps rooms even.
A new air conditioner installation usually makes sense when the compressor has failed on an older system, repairs keep adding up, or the system runs on R-22 refrigerant and has a leak.
A repair is usually the better call when the system is in good shape and one part, such as a capacitor or a fan motor, has failed. A technician can look at the system's age and condition and give you upfront pricing for both, so you can compare.
How Much Does Air Conditioner Installation Cost?
Cost depends on the new system and how much of the existing setup can stay. Factors that can affect the cost include:
- System size: Based on how much cooling your home needs.
- Efficiency and staging: The SEER2 rating, and whether the system is single-stage, two-stage or variable-speed.
- Coil and line set: Whether the indoor coil or line set needs replacing.
- Electrical work: Such as a new disconnect, breaker or wiring.
- Furnace compatibility: Pairing with your furnace, or replacing it too.
- Access and permits: Basement access, the outdoor unit location, permits and any rebates.
You'll get upfront pricing before any work begins.
Why Choose On Time Experts Heating, Air & Plumbing for Air Conditioner Installation?
We fit the system to the house and tell you plainly what it will cost.
Clear recommendations: If your current system can be repaired for a fair price, we'll tell you that before we talk about a new one.
Matched systems: We pair the condenser, coil and furnace blower.
Upfront pricing: You get a price for each option before any work starts.
Schedule Air Conditioner Installation
Tell us about your home and we'll look at your current system, lay out your options and price each one.
No pressure, and nothing gets installed until you've picked the system that fits.