Open 24/7 for emergencies
Replacing just the air conditioner in Hamilton runs $5,942 to $14,450 installed, keeping the propane furnace you have.
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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5.0 stars across 1,131 reviews
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 Hamilton
The Census counts 373 of the 1,298 owner homes in 20158 heating with propane, and those are the houses this page is written for: a propane furnace inside, a condenser outside, and a coil on top of the furnace that the two share. Electricity heats 665 homes, more than half, and there the outdoor unit is usually a heat pump that heats as well, so its replacement is a heat pump system, $8,499 to $21,650. Piped gas reaches only 22 owner homes. So in Hamilton an AC on its own is a real job, just the smaller of the two.
Age splits by decade. The Census dates 386 homes in the ZIP to the 2000s and 271 to the 2010s. A condenser the builder set on one of the 2000s houses is at or past twenty now, beyond the roughly 18 years federal planners give central air in Virginia, and a pre-2010 unit is probably on R-22. That refrigerant has been out of production since 2020, so a leak is where repairs on it stop adding up. The 2010s units are the other story: they run on its replacement, which can still be serviced, and are usually worth a fix. The data plate on the condenser’s side shows the date and the refrigerant.
Then the older wave. The Census counts 303 homes from the 1970s and 249 from before 1960, and by the Town’s own plan most houses inside the limits are late Victorian. Houses like those have usually seen more than one air conditioner come and go, each hooked to ductwork, copper and a drain line that were there first. When the condenser goes, the coil on the propane furnace and the copper out to it get a look too: a new A2L condenser comes with its own matched coil, and an old line set may be the wrong size for it.
Storms are Hamilton’s usual way of ending an air conditioner early. Thunderstorm winds put at least thirty trees down across town on July 25, 2010, and gusts near 61 knots damaged a roof on Meadowlark Drive on July 21, 2019. A limb through the fan guard of an old condenser tends to settle the repair question on the spot. The permit for a new one comes from Loudoun County, inside the town limits and out, since its fee schedule lists replacing central air conditioning as permit work.
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
ZIP 20158 as a whole: every Hamilton address, the Town and the countryside around it. The Census place for the Town alone has too few homes for steady figures.
When it’s time
Switch the cooling off at the thermostat and look before it runs again: a crushed fan guard, fins folded flat, the copper line pulled or its insulation torn. On a unit from the 2010s that’s often a repair. On a 2000s original, especially one on R-22, the $99 diagnostic should come back with the repair and the replacement range side by side.
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.
Choosing who installs it
Questions to ask anybody who quotes you, us included.
In plenty of Hamilton’s propane houses the unit out back is a heat pump, heating the mild days before the furnace takes over. From the yard it looks like an air conditioner. Swap in a plain AC and the propane tank carries every heating hour again, so the quote should name what’s out there now and price like for like first.
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.
Tyler from SwiftPro is very knowledgeable and professional on HVAC. Tech Edis and Rony are very professional and done good job to install AC
Where we work
Next door to Hamilton: Paeonian Springs, Waterford, Purcellville, Leesburg and Lovettsville.
Questions
Probably not. A house built around the ZIP’s 1988 median would be on its second condenser by now if the first lasted the 18 or so years the federal figure allows. Read the data plate: the date is printed or coded into the serial number, and the refrigerant is named. If it says R-22, price the replacement before a leak forces it; on anything newer, a repair usually still makes sense.
Often, yes. The Purcellville station, 2.6 miles west-northwest of town, averages about 30 days a year at 90 or hotter, and July nights there average 65.5 degrees, so the house gets a break after dark. An air conditioner sized to the house as it is now, insulation and windows included, can come out smaller than the one it replaces, and it runs longer cycles that pull more damp from the air.
$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 Hamilton 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.