The cost of a new AC installation depends on the size of your home, the tonnage and efficiency rating of the unit, the condition of your existing ductwork, and how accessible your attic or mechanical space is. There's no single number that applies to every house, but a licensed technician can walk your home and give you an accurate quote.
What Drives the Price of a New AC Installation?
A few factors matter more than anything else when it comes to installation cost. Understanding them helps you ask the right questions before you get a quote.
System size (tonnage). A unit that's too small for your square footage will run constantly and never quite catch up, especially during peak summer heat. A unit that's too large will cycle on and off too fast, which shortens its lifespan and leaves your home humid. Correct sizing is based on a load calculation, not just the square footage of the house.
Efficiency rating. Higher SEER ratings generally cost more upfront but use less energy over the life of the system. We've covered how to pick the right rating for this climate in our SEER ratings guide if you want the full breakdown.
Ductwork condition. If your existing ducts are undersized, leaky, or laid out for an older, smaller system, they may need modification to work well with a new unit. This is one of the biggest swing factors in any installation, and it's something that's hard to estimate without an in-person look.
Access and layout. A unit tucked in an easy-to-reach side yard with a straightforward line set run costs less labor than one requiring rooftop work, tight crawlspace access, or a longer refrigerant line run.
Removal and disposal of the old system. Pulling out an old condenser and air handler, and properly disposing of the refrigerant, is part of almost every install and adds to the scope of the job.
Is It Worth Paying More for a Higher-Efficiency Unit?
In Washington County's climate, where AC systems run hard for several months a year, a higher-efficiency unit tends to pay back some of its higher upfront cost through lower energy bills over time. Whether that trade-off makes sense for your household depends on how long you plan to stay in the home and your current energy costs. This is a conversation worth having with your technician rather than deciding based on sticker price alone.
Should You Replace Ductwork at the Same Time as the AC Unit?
If your ducts are old, poorly sealed, or sized for a different system, replacing or modifying them during the same job can save you a second disruption later and often improves comfort right away. It also tends to be more cost-effective to handle duct work and unit installation in a single visit instead of two separate ones. Homes with hot and cold spots are frequently dealing with a duct issue as much as an equipment issue.
What About Permits and Inspections?
Most jurisdictions in Southern Utah require a permit for a full AC system replacement, and a licensed contractor should handle that as part of the job. Skipping this step can create problems later, particularly if you sell the home and a buyer's inspector flags unpermitted HVAC work.
Getting an Accurate Quote
Because installation cost depends so heavily on your specific home, the most reliable way to know what you're looking at is an in-home evaluation. Our AC installation page has more detail on how we approach sizing and system selection, and we serve homeowners throughout St. George, Cedar City, Hurricane, Washington, and Ivins. If your current system is older and you're weighing a repair against a full replacement, our repair or replace guide walks through how to think about that decision before you commit to either path.
FAQ
How long does a new AC installation take? Most straightforward replacements can be completed in a single day. Jobs that involve significant ductwork changes or difficult access may take longer.
Can I install a new AC unit without replacing the ductwork? In many cases, yes, if the existing ducts are in good condition and properly sized for the new system. A technician can confirm this during an in-home evaluation.
Does a bigger house always need a bigger AC unit? Not necessarily. Insulation quality, window placement, ceiling height, and layout all affect the load calculation, so two homes of the same size can need different system sizes.