Open 24/7 for emergencies
AC replacement in Chantilly runs $5,942 to $14,450 installed, in 20151 or across the line in South Riding, with your gas furnace kept.
Price range
$5,942-$14,450
8yrs @ 7.99%
$84/mo
15yrs @ 9.99%
$64/mo
Monthly figures on the starting price, the whole price financed, on approved credit. The lender sets the final terms. How financing works
Get your price in writing
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One of our HVAC technicians moving a new condenser up a driveway, the van behind him.
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
Our own HVAC installersA dedicated heating and cooling team, separate from our plumbers
Price in writing firstYou see every option priced before anything is ordered
What it costs
The same price book our estimator runs on, for a central air conditioner on its own, keeping the furnace you have. A single-stage unit on a small house sits near the bottom; a variable-speed one on a big house, near the top.
A central air conditioner alone, keeping your furnace, installed
$5,942 to $14,450
or $99/mo at 0% APR for 60 months
An air conditioner and furnace together, installed
$8,898 to $23,000
or $148/mo at 0% APR for 60 months
A heat pump in the AC’s place, installed
$8,499 to $21,650
or $142/mo at 0% APR for 60 months
Diagnostic visit, if it may be worth fixing
$99
Monthly figures: 60mo @ 0% APR on each starting price, the whole price financed, on approved credit. Longer plans lower the payment and cost more in total. The lender sets the final terms. How financing works
The HVAC replacement cost estimator narrows it to your house. Then a tech measures, and you get the installed price in writing before anything is ordered.
With Comfort+ membership at $199 a year, the diagnostic visit is included, and half of each repair bill is banked toward replacing that system, up to $1,500.
What’s different in Chantilly
About half the Chantilly addresses we work at are on the Loudoun side, where the mail still says Chantilly. That’s South Riding, in 20152, and it’s gas country: more than eight in ten owners there heat with gas, so the question is usually the air conditioner by itself. The typical South Riding house went up in 2006, and nearly eight in ten since 2000. Plenty still cool with the builder’s condenser, close to twenty summers old and from the last years new systems were charged with R-22.
Nearly half of South Riding’s homes are townhouses, and in many the coil sits upstairs, on the furnace in the attic or a closet off the top hall, over the bedrooms. Replacing the AC means working up there too: the new coil goes in wherever the furnace is, and the copper lines from the condenser out back may run inside finished walls. Ask whether the quote reuses those lines or replaces them, and why. The bigger single-family houses often have a second condenser for the upstairs, and each one is its own replacement.
On the Fairfax County side, in 20151, the houses are older and the heat is split. The typical owner home dates from 1987 and about six in ten went up between 1980 and 1999, so the AC out back is often the second or third. Just over half the owners heat with gas and more than four in ten with electricity, which here mostly means a heat pump, and those houses replace a heat pump, not an AC. In the gas houses the furnace usually stands in the basement with the coil on top.
The county line decides the paperwork. South Riding is Loudoun County, whose fee schedule lists replacing central air conditioning as mechanical equipment work. In 20151, Fairfax County treats the same swap as mechanical permit work and wants an A2L certification for the system filed alongside it, since today’s condensers are charged with one of the newer A2L refrigerants. Those units run at their own pressures, so the coil and the line set have to suit the new refrigerant, not just the old pad.
Neighborhood by neighborhood
Census figures for the owner-occupied homes in each place, and what that usually means for the AC that’s there now.
| Place | Median home built | Most homes are | Heated with | The AC there now |
|---|---|---|---|---|
| South Riding | 2006 | single-family houses, about 5 in 10 | gas, about 8 in 10 | Townhouse condensers in tight side yards and on decks. |
| Chantilly | 1987 | single-family houses, about 6 in 10 | gas, about 5 in 10 | 1980s and 90s houses, many on their second air conditioner. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
In a South Riding house still on its mid-2000s builder unit, a condenser that hums without starting, or blows warm after a winter off, often points at the compressor or the capacitor giving out. At close to twenty years, and probably on R-22, the repair price and the replacement range belong on the same estimate before anyone opens the refrigerant circuit.
An air conditioner put in before 2010 most likely holds R-22, which hasn’t been made since 2020. A leak on one of those usually ends the repair road.
A house from the 2000s often cools with the condenser it was built with. Past fifteen years, compressors and fan motors start to go, one after another.
Permits, locally
Our Virginia Class A contractor license, 2705192276, is on the side of the van.
Choosing who installs it
Questions to ask anybody who quotes you, us included.
A Chantilly mailing address can sit in Fairfax County or in Loudoun, and the permit, the fees and the inspector all follow the county, not the post office. An installer who works both sides should ask for your ZIP and tell you which office the job goes through before you sign anything.
Ask how they picked the size. Copying the old nameplate repeats whatever was guessed when the house was built.
The outdoor unit and the coil on the furnace are rated as a pair. Ask whether the quote replaces both, and what happens to the line set.
A good company puts the repair price next to the replacement range and lets you choose. Already holding somebody’s big number? Take the free second opinion first.
Two of our crew going over a work order before the day's calls.
From our Google reviews
5.0 stars across 1,131 reviews. Read them on our reviews page.
Arrived within an hour on a Sunday morning and provided great service.
Called SwiftPro around 5 am and their electronic system scheduled an appointment for us same day.
They replaced my AC system and got it up and running with great service. Moises and Efrain are great!
Where we work
Next door to Chantilly: Centreville, Catharpin, Herndon, Aldie and Oakton.
Questions
Not just for its age, if it still cools well. At close to twenty years it’s near the end of the usual run, though, and if it’s on R-22, the first leak makes the choice for you. Know your number now, while it’s working. If it does fail, the $99 diagnostic tells you whether it’s worth fixing first.
Probably not. More than four in ten owners in 20151 heat with electricity, mostly a heat pump that does the cooling too, and replacing one means a new heat pump and air handler, priced at $8,499 to $21,650. This page is for a gas furnace with a plain air conditioner outside. The label on the outdoor unit says which you have.
$5,942 to $14,450 installed for a central air conditioner on its own, keeping the furnace you have; size and efficiency set where yours lands. An AC and furnace together run $8,898 to $23,000. The HVAC replacement cost estimator gives your house its own number.
It’s worth pricing. A heat pump cools exactly like an AC and also heats on mild days, so with your gas furnace it becomes dual fuel. A heat pump system runs $8,499 to $21,650 installed, and we’ll price it both ways.
Ready when you are
Call, or send the form at the top. A tech measures the house and puts the installed price in writing before anything is ordered, and if the old AC is worth fixing, you’ll hear that first.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
Virginia Class A contractor license #2705192276
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Chantilly and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,131 reviews on Google, Angi, Yelp, the BBB and Facebook. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
From SwiftPro Heating, Cooling & Plumbing in Chantilly. Housing figures are the Census Bureau’s American Community Survey, 2020 to 2024, for each place named; permit, water and sewer facts link to each office’s own page and were checked in September and October 2026.