Old floors, old piano, old glass
Heart pine floors in a 1930s Alexandria rowhouse shrink fast in February, and single-pane windows show the first fog of the season. Both are signs the air is running dry.
Alexandria, Virginia
Whole-home humidifiers in Alexandria.
For whole-home humidifier repair in Alexandria, if the humidifier you have stopped working, finding out why is the $99 diagnostic visit. Call SwiftPro, rated 5.0 stars across 1,130 reviews, at (703) 997-9757, 24 hours a day, 7 days a week.
For whole-home humidifiers in Alexandria, SwiftPro is rated 5.0 stars across 1,130 reviews and works under Virginia Class A contractor license 2705192276. Whole-home humidifiers in Alexandria, where a humidifier needs ducts, and plenty of older City houses and condo units run on something else. A new one is priced at your house, in writing, once we’ve seen the furnace, the ductwork and the nearest water line. Through October 31, code HUMID250 takes $250 off a humidifier plumbed into the ductwork.
- Priced in writing at your house
- Our own HVAC technicians
- Set and tested before we leave
5.0 stars across 1,130 reviews
A whole-home humidifier mounted on the supply duct above the furnace, with its own water line and drain.
Get your price in writing
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Licensed and insuredVirginia Class A contractor #2705192276
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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
What a whole-home humidifier costs in Alexandria.
We price it in writing at your house, the same way our whole-home humidifier page explains. More on the numbers in our humidifier cost guide.
Diagnostic visit, when the humidifier you have stopped working
$99
Whole-home humidifier installed on your furnace or air handler
Priced at your house, in writing, before any work
Coupon HUMID250, through October 31
$250 off the install
Prices checked .
What moves the price is the model and the path to it: a bypass model on an open basement furnace with a water line close by is the simple end, a fan-powered model in a tight closet with a long run for water and a drain is the other.
If the house already has a humidifier that stopped, we look at it first. Often it’s a crusted water panel, a closed saddle valve or a control that lost its wiring, and that’s a repair, not a new unit.
What’s different in Alexandria
Alexandria is where we first ask whether you have ducts at all.
A whole-home humidifier rides on a ducted system. It sits on the furnace or air handler and sends moisture out through the supply air. A lot of Old Town and Del Ray houses were built with radiators, and more than half of Alexandria’s homes are in apartment and condo buildings. If the heat in your place never touches a duct, we’ll tell you straight that a whole-home unit doesn’t fit and a good room unit is the better buy.
Where there are ducts, the owner mix splits about 57 percent gas and 41 percent electric. Gas houses suit a bypass Aprilaire, which borrows the furnace’s warm air. The electric ones are mostly heat pumps, and that air runs cooler, so we reach for the fan-powered model instead. The unit in the closet of a West End condo usually falls in that second group.
Close to three in ten homes here were built before 1960, and the brick and plaster ones are the hard cases. We don’t cut new duct through a plastered ceiling to make a humidifier work. The existing system decides the spot, and sometimes the answer is the attic or crawlspace air handler an earlier owner added in a renovation. A well-kept 1925 rowhouse in Del Ray or Rosemont is worth that care.
In a condo, the humidifier needs a water line and a place for the drain to go, and the association may have a say about both. Ask the management office before you call anybody, ours included. If you already own a unit that quit, the $99 visit finds out whether it’s the pad, the valve or the control.
Neighborhood by neighborhood
What fits on the system across Alexandria.
Census figures for the owner-occupied homes in each place, and the humidifier that usually suits houses like them.
| Place | Median home built | Most homes are | Heated with | What usually fits |
|---|---|---|---|---|
| City of Alexandria | 1970 | condo and apartment buildings, about 5 in 10 | gas, about 6 in 10 | A bypass model with more output, for a draftier house. |
| Rose Hill | 1969 | single-family houses, about 7 in 10 | gas, about 7 in 10 | A bypass model with more output, for a draftier house. |
| Franconia | 1986 | townhouses, about 5 in 10 | electricity, about 6 in 10 | A fan-powered model, since heat pump air runs cooler. |
| Fort Hunt | 1963 | single-family houses, nearly all | gas, about 8 in 10 | A bypass model with more output, for a draftier house. |
| Kingstowne | 1994 | townhouses, about 5 in 10 | gas, about 7 in 10 | A bypass model on the gas furnace’s ductwork. |
| Woodlawn | 1976 | townhouses, about 4 in 10 | electricity, about 6 in 10 | A fan-powered model, since heat pump air runs cooler. |
| Lincolnia | 1982 | single-family houses, about 4 in 10 | gas, about 7 in 10 | A bypass model on the gas furnace’s ductwork. |
| Mount Vernon | 1967 | single-family houses, about 7 in 10 | gas, about 7 in 10 | A bypass model with more output, for a draftier house. |
By the numbers
Alexandria houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey. Median year built and heat count owner-occupied homes only.
The City of Alexandria
- Median home built1970 Census
- Built before 1980about 6 in 10 Census
- Built since 2000about 2 in 10 Census
- Most homes arecondo and apartment buildings, about 5 in 10 Census
- Heated withgas, about 6 in 10 Census
- Rentedabout 6 in 10 Census
- Older houses let in more outdoor air, so they dry out faster and need a humidifier with more output to hold the number.
- Many homes here are townhouses or condos with the system in a closet. A fan-powered model fits where there’s no room for a bypass duct, and in a condo the association may need to approve the water line.
The signs
When a Alexandria house is too dry in winter.
Static every time you touch a doorknob
A zap off every light switch in January means the air in the house is well under 30 percent. Outdoor winter air holds little water, and heating it dries it further.
Floors and trim open up gaps
Wood gives up water in dry air. Gaps between floorboards, a cabinet door that sticks, or a piano that won’t hold its tuning through winter all point the same way.
Need whole-home humidifiers in Alexandria?
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Choosing who does it
How to pick who installs a humidifier in Alexandria.
Questions to ask anybody who quotes you one, us included.
Will they tell me if my radiator house can’t take one?
A good installer looks at how your house is heated before quoting a model. If the answer is no ducts, you should hear that on the first visit, not after a deposit.
Did they ask where the water and the drain come from?
A humidifier needs a water line and, for most models, a drain. Whoever looks for both before quoting is the one who won’t surprise you on install day.
Did they say which kind, and why?
A bypass model, a fan-powered model and a steam model each suit different systems. Ask why theirs fits your furnace or heat pump, not just what it costs.
Two of our crew going over a work order before the day's calls.
From our Google reviews
What our customers say.
5.0 stars across 1,130 reviews. Read them on our reviews page.
Hard to find service like this in Alexandria.
…we had swift and professional responses for multiple plumbing and HVAC needs in our Rosemont Alexandria condo
Excellent HVAC service for a fair and reasonable price. Moises Rojas fixed my home’s whole house humidifier, which I had no idea wasn’t working for over two years since moving into this house, and now the air in my home is very comfortable.
- 5.0stars across 1,130 reviewsHow we count them
- ABBB Accredited, A ratingCheck it on bbb.org
- 2026Voted a Nextdoor Neighborhood Faves winner two years running: 2026 in 30 Northern Virginia neighborhoods, 2025 in Emerald Chase (Herndon) and Hunters Run (Chantilly)See it on Nextdoor
- #1BusinessRate Best of 2026: the top-ranked heating contractor in Fairfax, VirginiaSee our BusinessRate score
- Class AVirginia contractor, license #2705192276Look it up with DPOR
Where we work
Whole-home humidifiers in every Northern Virginia town we serve
Next door to Alexandria: Arlington, Springfield, Falls Church, Annandale and Fort Belvoir.
Fairfax County
Arlington County
Loudoun County
Prince William County
Fauquier County
Stafford County
Every town on one page
Questions
Humidifier questions from Alexandria.
Can a humidifier go in an Alexandria condo?
Usually yes, if the unit has its own ducted air handler and a water line nearby. Check your association’s rules on water lines and drains first.
Does a humidifier work with radiator heat?
Not a whole-home one. It needs air moving through ducts to carry the moisture. For radiator houses, room units are the practical answer.
How much is a whole-home humidifier in Alexandria?
It’s priced at your house, in writing, because the model and the work depend on your system, your ducts and where the water line is. If you have one that stopped working, the diagnostic visit is $99.
What humidity should the house be at in winter?
The EPA says keep indoor humidity between 30 and 50 percent. On the coldest nights we run it nearer the low end so windows don’t sweat, and an Aprilaire with an outdoor sensor turns itself down for you.
Ready when you are
Find out what your house needs.
Call, or send the form at the top. We look at the furnace, the ducts and the water line, and you get the price in writing before any work starts.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
SwiftPro Plumber & Water Heaters
4200 Lafayette Center Dr, Suite N, Chantilly, VA 20151
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 Alexandria and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,130 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.