Usually the person asking us is standing in their kitchen wiping fog off the window with a paper towel, and for most Georgia homes we tell them the same thing, which is that a whole home dehumidifier is worth it, and even more so when there’s a musty smell in the hallway, a crawl space that never dries out or a kid whose allergies kick in as soon as they get home from school. Because a whole home dehumidifier rides along with the HVAC system you already own, it dries out every room at the same time without anybody having to think about it, and your family, your house and your heating and cooling equipment all come out ahead, which is a bigger deal than usual with the wet winter we’ve got coming.
How wet are we talking? NOAA has the odds of a very strong El Niño this fall and winter above 90%, and when that happens the Southeast usually gets above-normal precipitation, so expect plenty of rain and gray skies around Georgia, plus those mild, damp afternoons when the heat barely bothers to come on. If you’ve ever wondered how a house can feel muggy in January, that’s how.
We bring up indoor humidity with customers more than they expect us to, and these three facts are a big part of why:
- Let the humidity get past 60% and mold moves right in. Our rule of thumb comes straight from the U.S. Environmental Protection Agency, which recommends keeping indoor relative humidity under 60%, and ideally somewhere between 30% and 50%, if you want mold to stay out of the picture.
- Mold gives you less time than you’d think. In most cases, the EPA says, mold won’t grow if wet or damp materials get dried within 24 to 48 hours, which is a pretty short window and the reason we put so much stock in keeping moisture under control day in and day out.
- Anyone with asthma will feel the difference. If somebody in your house has asthma, the American Lung Association’s advice is to hold the humidity inside between 30% and 50%, and the reasoning is simple enough: dust mites and mold get along great in damp air, and asthmatic lungs don’t.
Coming up, we’ll talk about why houses around here get damp in the winter and the signs to look for, and then we’ll get into how a whole home dehumidifier works and how we’d help you decide if your house needs one (our post on how to manage humidity levels covers some of the basics too).
Why Georgia homes get damp in winter
Ask most people when humidity is a problem and they’ll say summer, which makes sense, but here in Georgia it has a way of sticking around well after the leaves fall, and an El Niño year gives it even more reasons to stay.
A wetter El Niño season
When El Niño runs strong, the subtropical jet stream sags down across the southern United States and keeps sending storms our way, so forecasters are expecting above-normal rainfall for Georgia this winter, with long, gray, damp spells sitting between the cold snaps (if you want the bigger picture, here’s how El Niño and La Niña each change the winter).
And that water doesn’t stay out in the yard where it belongs. Think about how many times a day the back door swings open with the dog going in and out, or the hairline gaps around an old window frame, or the soggy dirt that sits right up against the foundation for days after a storm. When it’s cold and dry out, the furnace runs enough to dry a little of that up for you. On one of those mild, drizzly days, though, it hardly comes on, so the dampness just stays.
Mild, damp days when heat barely runs
Anybody who’s spent a winter in central Georgia knows how many days land in the 50s and 60s, and on a day like that the furnace or heat pump might only kick on now and then before dinner. What people forget is that the air conditioner is off too. All summer long it was quietly wringing water out of your air without you thinking about it, and now it’s sitting in the side yard doing nothing while the humidity inside keeps creeping higher.
Then there’s just living in the house. A pot of soup on the stove puts water in the air. So does a teenager’s endless shower, and believe it or not, so does everybody sleeping and breathing all night. With the windows shut for the season, all that moisture has nowhere to escape, and over a few weeks you’ll notice it most in the bathrooms and the kitchen, and in the bedrooms where the doors stay closed.
Crawl spaces, slabs and basements
If we had to name the single biggest moisture source we run into in Georgia homes, it’d be the crawl space. Between damp soil, drainage that isn’t great and vents left open, a crawl space can stay humid all year, and because warm air rises, the moisture and the musty smell from under the house drift right up into the rooms and the ductwork.
Slabs and basements aren’t off the hook, either, especially after a big rain. When gutters overflow or the yard tilts toward the house, water pools along the foundation, and a winter with above-normal rainfall is going to find every one of those weak spots more than once.
Signs your home has too much humidity
Humidity rarely makes a big entrance. Most of the time it leaves little clues all over the house for weeks before anybody puts them together, and if a couple of these sound familiar, we’d take a closer look.
Condensation on the windows and walls
We’d bet you’ve had a morning this year where you came into the kitchen half awake and the window over the sink was fogged up, or dotted with little beads of water on the inside of the glass. That happens when warm, damp air in the house hits the cold glass and turns back into water, it’s one of the clearest signs there’s too much moisture indoors, and the EPA lists condensation as one of the common signs of high humidity.
Now, a bit of fog after a hot shower doesn’t mean anything. Condensation you see every single day is another matter, especially when it runs down the glass or leaves puddles on the sills, because sooner or later that stains or rots the window frames and gets mold going around the edges, so we’d also check the exterior walls, the closets and the wall behind the dresser for damp spots.
Musty odors and visible mold
Usually your nose figures out there’s mold or mildew before your eyes do, since that musty, earthy smell tends to show up first, maybe in a closet or a bathroom, down in the basement or the crawl space, or right when the HVAC system starts up. When the smell only hits you as the system starts blowing, our first suspect is moisture hiding in the ductwork or around the indoor coil (and if that’s your situation, we wrote up how to clean and prevent mold in air vents).
When mold gets far enough along that you can see it, it’s usually black, green or white specks on a bathroom ceiling, a window frame or the grout, or on that box of old photos nobody’s opened in years. Wiping off a small patch on a hard surface is fine. If it keeps coming back, though, the moisture behind it is still there, and in a lot of houses that’s when we start talking about a whole home dehumidifier.
A clammy feel, allergies and damage
Some rooms just feel clammy, even when the thermostat swears it’s a perfectly normal temperature, and when we walk into one of those, it’s almost always the humidity, which is also why the bath towels never seem to dry and the sheets feel a little damp when you get into bed. In winter it can actually make a room feel colder, because moist air pulls heat off your skin, and plenty of people respond by turning the thermostat up and paying more on the heating bill for a problem that heat won’t really fix.
Dust mites and mold are two of the most common indoor allergy triggers there are, and both of them thrive when the humidity runs high, so if your allergies or asthma act up at home more than anywhere else, the air in the house might be the reason. Keep an eye out for what it does to the house, too, whether that’s paint starting to peel, a wood floor that’s warped, a bathroom door that suddenly sticks or rust showing up on the fixtures.
How a whole home dehumidifier works
If you’ve ever owned one of those portable dehumidifiers, you already understand the basic idea, since a whole home dehumidifier pulls moisture out of the air the same way, it just takes care of the entire house instead of one room, and here’s how that works in practice.
How it connects to your HVAC system
When our techs install a whole home dehumidifier, it goes in right beside your existing heating and cooling equipment, most often near the air handler or furnace, which might be in the crawl space, the attic or the basement depending on the house. Once it’s tied into the ductwork, the whole home dehumidifier draws damp air from the rooms, wrings the moisture out of it and sends the drier air back out through the very same vents your heating and cooling already use.
We usually explain the inside as a little air conditioner that only cares about water. The air passes over a cold coil, the moisture drips off as water, and the air keeps moving, only without getting chilled the way it would with your AC, and that’s the trick that makes it so useful on a mild, soggy afternoon when the house feels heavy and the last thing you want is the air conditioning on.
Whole home dehumidifier vs portable units
We’ve got nothing against portable dehumidifiers, and they do fine in one damp room like a basement or a bathroom. They just don’t reach past the room they’re sitting in, somebody ends up emptying the water bucket over and over, and some of them hum loud enough to notice, which is why we so often walk into houses with several of them scattered around and a family that’s tired of tending to all of them.
A whole home dehumidifier, on the other hand, reaches every room through the ductwork and sits quietly in the crawl space or attic where nobody ever has to look at it, and since it drains by itself, there’s no bucket at all, and it can pull a lot more water out of the air in a day than most portable units ever will. If the dampness shows up in more than one room of your house, we’d go with the whole home dehumidifier every time.
Whole home dehumidifier controls and drainage
Your whole home dehumidifier will usually come with its own little control, called a dehumidistat, and you just set it to the humidity you want, which for most of our customers is somewhere in the 40% to 50% range. After that you can pretty much forget about it, since it only turns on when the air gets damper than your setting and shuts back off once things dry out.
All that water goes out a small line to a floor drain, a condensate pump or the outside of the house, pretty much like your air conditioner’s condensate does, and when we install one, our tech makes sure the line has the right slope and is protected, so it keeps draining winter, spring, summer and fall. Some models can also bring in filtered fresh air, which really helps in a house that’s sealed up tight all winter.
Is a whole home dehumidifier worth it?
We’d judge a whole home dehumidifier on three things, starting with the air your family breathes, then the wear and tear it saves the house and the HVAC system over the years, and finally how comfortable you feel and how much energy you use as the seasons change.
Healthier indoor air with a whole home dehumidifier
Mold, mildew and dust mites all do their best in damp air, so when you keep the humidity in the 30% to 50% range the EPA recommends, you’re making the house a much less comfortable place for them, and for anybody with allergies or asthma that can mean fewer flare-ups and a lot more good nights of sleep.
You’ll probably notice the smell first, or really the lack of it, since controlling the humidity cuts down on musty odors and that stale, stuffy feeling a house gets after a couple of months closed up. And because a whole home dehumidifier treats every room, the bedrooms and closets get the benefit too, not just the one corner where a portable unit would’ve been parked.
Protecting your home and your HVAC system
The thing about moisture is that it’s patient, and it usually takes its time doing damage, so by the time most homeowners notice, the repair bill isn’t small. We’ve seen it warp wood floors and trim, peel paint and rot out window frames, and it’ll rust metal and ruin stored keepsakes too, while up in the attic or under the house it soaks the insulation and gets the wood rotting.
It isn’t kind to your HVAC system either, since damp air lets mold grow on the indoor coil, in the drain pan and through the ductwork, which drags down both your air quality and your efficiency. A whole home dehumidifier keeps all of that drier and cleaner, and in our experience the heating and cooling equipment runs better and lasts longer for it.
Year-round comfort and energy savings from a whole home dehumidifier
Around here a whole home dehumidifier doesn’t really get a season off. It takes care of those damp, mild winter days when the heat isn’t running much, it handles the muggy stretches in spring and fall, and in the summer it takes some of the moisture-removal work off your air conditioner’s plate.
Drier air also just feels better at the same temperature. Plenty of our customers find they can set the thermostat a couple of degrees higher in summer and still feel cool, which can bring the cooling bill down, and in winter, getting rid of that clammy dampness can make a room feel warmer without touching the heat. Since heating and cooling eat up the biggest share of most homes’ energy use, those little adjustments add up over a year.
Deciding if a whole home dehumidifier is right for you
We’ll be honest, not every house needs a whole home dehumidifier, and sometimes we’d tell you to try a simpler fix before spending the money. Here’s how we’d help you decide, and how to get started the right way if you do.
Who benefits most from a whole home dehumidifier
Here’s the honest test we use. If your hygrometer keeps reading somewhere above 50% to 60%, or you’ve wiped the same mold off the same bathroom ceiling more than once, a whole home dehumidifier is probably going to change how the house feels. Houses built over a crawl space tend to land in that group, and so do the ones with a finished basement, or that sit under big trees and never see much sun.
It’s also the first thing we bring up with families who fight allergies or asthma, and with folks who have nice hardwood floors or wood furniture they’d hate to see warp. If you’re already emptying the buckets on a couple of portable units every day, you probably don’t need us to convince you. One more hint is a house that feels sticky in July even though the air conditioner keeps it cool, and either way, a cheap humidity meter will tell you where you stand before you spend a dime.
Fix the moisture sources first
Before anybody spends money, we’d go after the moisture at its source, because a whole home dehumidifier has a much easier job in a house that isn’t taking on water from outside. The best time to see what’s happening is during a good hard rain. Grab an umbrella and walk around the house, and watch where the downspouts let out and which way the water runs across the yard, since anything pooling against the foundation is going to end up under the house sooner or later.
Indoors it’s mostly about habits. Running the bathroom fan through every shower and the kitchen fan while dinner’s cooking makes a real difference, and so does a dryer vent that goes all the way outside. After that we’d check the HVAC condensate drain and then crawl under the house with a flashlight, since standing water, wet insulation or open vents down there are worth knowing about, and it may be time to ask about sealing or encapsulating the crawl space. Each of those takes some of the load off a whole home dehumidifier, and once in a while they fix the problem so well the house never needs one.
Professional whole home dehumidifier sizing and installation
There’s more than one size of whole home dehumidifier, and the right one comes down to your home’s square footage, the layout, how it was built and how much moisture it takes on. Undersize it and it’ll run all day without ever catching up, oversize it and you’ve paid for capacity the house will never use.
So the first thing a qualified technician should do is measure the humidity and figure out where the moisture’s coming from, and only after looking over your ductwork should they recommend a capacity and a spot for the whole home dehumidifier to go. They’ll also set up the drainage and controls so it plays nicely with your furnace or heat pump, and some regular maintenance, mostly cleaning or replacing its filter, keeps it running efficiently for years (that’s what our dehumidifier repair team is for).
Frequently asked questions about whole home dehumidifiers
Is a whole home dehumidifier worth it in Georgia?
In a lot of Georgia homes it pays off, since it keeps the moisture in check in every room all year long. You get help preventing mold and musty odors, protection for the house and the HVAC system and a more comfortable home, especially in a damp El Niño winter or one of our sticky summers.
What humidity level should I keep in my home?
Below 60% is the EPA’s line, and between 30% and 50% is the ideal. The American Lung Association points people with asthma to that same 30% to 50% range.
Can homes have humidity problems in winter?
More than you’d think, here in Georgia. Mild, rainy winter days, the cooking and showering every family does, and a damp crawl space can all keep the humidity inside high, particularly when the heating system isn’t running much.
What are the signs of too much humidity?
Foggy windows and a musty smell usually tip people off first, with a little visible mold or one room that’s always clammy not far behind. Allergies acting up, peeling paint, warped wood and sticking doors are all signs we’d add to the list.
How is a whole home dehumidifier different from a portable one?
Since a whole home dehumidifier is tied into your HVAC ductwork, it can reach every room in the house, and it drains itself and runs quietly where you won’t see it, while a portable one only helps whatever room it’s sitting in and needs somebody to empty its bucket.
Do I need to fix moisture sources before adding a whole home dehumidifier?
We’d recommend it, yes. Cleaning out the gutters, grading the soil away from the foundation, using your exhaust fans and fixing a damp crawl space all cut the moisture load, and then the dehumidifier doesn’t have to work nearly as hard.
Who should install a whole home dehumidifier?
You want a qualified HVAC technician doing the sizing and the installation. They’ll measure your home’s humidity, pick the right capacity for it and set up the drainage and controls so it works with the system you’ve already got.
Breathe easier this winter
A wet Georgia winter doesn’t have to mean musty air, foggy windows and mold worries. Put a whole home dehumidifier together with a few simple moisture fixes and the house stays drier, healthier and more comfortable no matter the season.
The Air Conditioning Specialist installs and repairs whole home dehumidifiers for homeowners in Covington, Milledgeville, Augusta, Athens and the surrounding Georgia communities. Our technicians measure your home’s humidity, figure out where the moisture is coming from and recommend a system that’s sized right for your house. Give us a call to set up an indoor air quality consultation or ask about dehumidifier installation, and let’s get your house ready before this El Niño winter settles in.