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AC replacement in Clifton runs $5,942 to $14,450 installed per air conditioner, with the furnace kept, in the Town or on the county side.
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 Clifton
The Town of Clifton covers about one percent of 20124’s land, and the rest is Fairfax County, where the median owner’s house dates from 1988 and nearly eight in ten went up between 1980 and 1999. The houses run big: six in ten homes in the ZIP have nine rooms or more, and a house that size often cools with two systems, one for the main floors and basement and one in the attic for the bedrooms. Each is its own air conditioner, with its own condenser, coil and age, so replacing the one that failed doesn’t commit you to the other.
A builder’s AC from the late 1980s is long gone, so the condenser out back is usually the second, sometimes the third. If it went in during the 2000s it most likely holds R-22, out of production since 2020, and that’s the one to plan for before its next leak. Gas heats about six in ten owner homes on the county side, the share highest in the 1980s subdivisions off Springstone Drive and Union Mill Road, and there the new coil goes on top of the furnace in the basement. A propane furnace takes a new AC the same way.
Inside the Town of Clifton the order of sign-offs matters. The Town doesn’t issue permits, but it signs off first, by letter, and Fairfax County won’t move the mechanical permit until that letter is uploaded to the county record. The county then wants its A2L certification for the new system, because today’s air conditioners are charged with one of those refrigerants. The whole town is the Clifton Historic District, so a condenser going into a new spot changes the outside of the building, and that takes a certificate of appropriateness from the Architectural Review Board.
The Town’s houses are almost all over 120 years old, so central air came long after them and went wherever it fit, with the air handler often in an attic or a crawlspace. A replacement there starts with the ducts and the drain, not the condenser. Out on the acreage along Clifton, Compton and Yates Ford Roads, a house with a standby generator needs one more look: the generator was sized for the AC the house had when it went in, and a new compressor starts differently, so its capacity gets checked before the old unit leaves.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
Clifton mail outside the town: five- to ten-acre lots in the Occoquan watershed on Clifton, Compton and Yates Ford Roads, mostly on septic, and the 1980s subdivisions off Springstone Drive and Union Mill Road on county sewer.
ZIP 20124 as a whole, the Town included: its own homes are too few for steady Census figures.
When it’s time
In a two-system Clifton house, that’s the attic air conditioner, the one you rarely see until it quits. If it’s the older of the pair, or still on R-22, put the repair price and the replacement range side by side before July. The basement system keeps its own schedule; it’s a separate condenser with its own years.
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.
It’s the pump at the heart of the outdoor unit and its costliest part. Out of warranty on an older unit, the repair can come close to half the price of a new AC, the point where Goodman says replacing may be the better money.
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 standby generator was sized for the air conditioners the house had when it went in. A new condenser’s compressor and fan draw differently, so ask the installer to look at the generator’s capacity and which circuits it carries. Finding a mismatch during the first outage, with the house heating up, is the expensive way.
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.
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 Clifton: Fairfax Station, Burke, Manassas, Centreville and Fairfax.
Questions
Ask the Town before anything is ordered. Moving the condenser, adding a second unit or running new lines up a wall people can see all change the outside of the building, which takes the Board’s certificate of appropriateness. Whether a like unit on the old pad needs it is the Town’s call. Either way its letter comes before the county permit.
Not quite. This range is for replacing a central air conditioner that’s already there, ducts and all. A Town house cooled by window units, with no ducts, is a new installation, and in a house over 120 years old, a ductless system often fits better than cutting duct runs through plaster. The Town’s letter and the Board still come first.
$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 Clifton 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.