Running a dehumidifier in winter usually does more harm than good
Most homes do not need a dehumidifier in winter. Cold air holds less moisture than warm air, so winter humidity is naturally lower — typically 30 to 50 percent indoors, which is the healthy range. Running a dehumidifier when humidity is already low wastes electricity and can dry out your skin, sinuses, and wood furniture. The exception is a basement or crawlspace that stays damp year-round, or a home with a specific moisture problem like wet laundry or cooking steam that you cannot vent outside.
The real winter problem is usually the opposite: air that is too dry. Heating systems warm air and reduce its relative humidity, sometimes dropping it below 30 percent. At that level, static electricity builds up, wood shrinks and cracks, and respiratory infections spread more easily. If your home feels dry in winter, a humidifier — not a dehumidifier — is what you need.
Key Takeaways
- Winter air is naturally dry, so running a dehumidifier wastes energy and can damage wood and skin.
- Healthy indoor humidity in winter is 30 to 50 percent; most homes reach this without help.
- Basements and crawlspaces may need year-round dehumidification because cold surfaces collect condensation.
- If your home feels dry in winter, the solution is a humidifier, not a dehumidifier.
- Check your humidity level with an inexpensive meter before running any moisture-control device.
Why winter humidity is naturally low
Cold air cannot hold as much moisture as warm air. When outdoor air at 20°F and 60 percent relative humidity enters your home and gets heated to 70°F, that same air suddenly has only 20 percent relative humidity — even though the actual amount of water vapor in it has not changed. This is why winter air feels dry without any dehumidifier running.
Your heating system makes this worse. Furnaces, heat pumps, and baseboard heaters all warm air without adding moisture back. Over the course of a heating season, indoor humidity can drop to 15 or 20 percent if you do nothing to counter it. That is when problems start: wood floors cup and crack, drywall joints separate, and viruses survive longer in the air.
A dehumidifier removes moisture that is not there. Running one in winter forces your heating system to work harder to warm the air back up after the dehumidifier has cooled it, and you end up paying to remove moisture you do not have.
When a basement or crawlspace needs winter dehumidification
Basements and crawlspaces are different from the rest of your home. They stay cool year-round, and cold surfaces collect condensation. Warm, humid air from upstairs or from outside seeps down, hits a cold wall or concrete floor, and the moisture condenses into liquid water. This happens in winter even when the rest of your house is dry.
If your basement stays damp or smells musty in winter, a dehumidifier can help. Run it only in the basement, not upstairs. Set it to maintain 50 to 60 percent humidity — not lower. A dehumidifier in a basement also helps prevent mold and protects stored items like books, photographs, and electronics.
Crawlspaces benefit from year-round dehumidification if they are vented to the outside. In winter, cold air enters the crawlspace, and any moisture in that air condenses on rim joists and pipes. A small dehumidifier or a crawlspace-specific unit can prevent rot and mold in these hard-to-reach areas.
How to tell if your home is too dry or too humid
Do not guess. Buy a hygrometer — a humidity meter — for $15 to $30. Digital models are accurate and straightforward to read. Place it in your main living area, away from bathrooms and kitchens, and check it over a few days. Healthy indoor humidity in winter is 30 to 50 percent. If you are consistently below 30 percent, your air is too dry. If you are above 50 percent, moisture is building up.
Signs of air that is too dry include static shocks, cracked wood trim, separated drywall joints, and dry skin or nosebleeds. Signs of air that is too humid include condensation on windows, musty smells, and visible mold or mildew on walls or ceilings.
Once you know your humidity level, you can decide what to do. Most homes in winter need nothing — they naturally fall into the healthy range. Some need a humidifier. Very few need a dehumidifier running in the main living space.
The cost of running a dehumidifier in winter
A typical dehumidifier uses 300 to 700 watts of electricity, depending on size and model. Running one for 8 hours a day costs roughly $0.30 to $0.70 per day, or $90 to $210 per month. In winter, when you are already paying to heat your home, this is wasted money. The dehumidifier cools the air slightly as it removes moisture, so your furnace has to work harder to bring the temperature back up.
The real cost is indirect: dry air damages wood, increases static electricity, and can make respiratory infections more likely. Running a dehumidifier makes this worse, not better. If your humidity is already low, you are paying to create a problem you then have to fix with a humidifier.
What to do if your home is too dry in winter
If your hygrometer shows humidity below 30 percent, use a humidifier, not a dehumidifier. A small tabletop humidifier in your bedroom or main living area can raise humidity to a healthy level. Ultrasonic and evaporative models are quiet and inexpensive. Whole-house humidifiers that attach to your furnace work better if you have the budget and want to treat the entire home at once.
You can also raise humidity without a device: hang wet laundry indoors to dry, leave bathroom doors open after showers, and keep a pot of water simmering on the stove while cooking. These methods add moisture to the air naturally.
Do not run a humidifier and a dehumidifier at the same time — they work against each other and waste energy. Choose one based on what your hygrometer tells you.
Winter dehumidifier settings if you do run one
If you have a basement dehumidifier or a specific moisture problem that requires one, set it carefully. Most dehumidifiers have a dial or digital control that lets you choose a target humidity level. In winter, set it to 50 to 60 percent, not lower. This prevents the air from becoming too dry while still removing excess moisture.
Empty the tank regularly or attach a drain hose so water flows directly to a floor drain or sump pump. A full tank stops the dehumidifier from working, and standing water can grow mold. Check the unit every few days in winter to make sure it is still running — cold temperatures can affect performance.
Turn off the dehumidifier if humidity drops below your target level. Many models have an automatic shutoff, but older units do not. Leaving it running when humidity is already low defeats the purpose.
Frequently Asked Questions
Can running a dehumidifier in winter damage my home?
Not directly, but it can make existing problems worse. If your home is already dry, a dehumidifier will dry it out further, causing wood to crack and drywall joints to separate. It also wastes energy and money. The damage comes from the unnecessary dryness, not from the machine itself.
Should I run my dehumidifier all winter or just sometimes?
Only if you have a specific problem like a damp basement. For the main living space, do not run it in winter at all. Check your humidity with a meter first. If it is already in the healthy range (30 to 50 percent), you do not need either a humidifier or a dehumidifier.
What humidity level should I aim for in winter?
Aim for 30 to 50 percent relative humidity. Below 30 percent, air feels dry and wood can crack. Above 50 percent, condensation forms on windows and mold can grow. Most homes naturally stay in this range in winter without any help.
Is it okay to run a dehumidifier in a finished basement in winter?
Only if your hygrometer shows humidity above 50 percent in that space. Basements stay cooler than the rest of the house, so they can collect moisture even when upstairs is dry. If you do run one, set it to 50 to 60 percent and monitor it regularly. Turn it off if humidity drops below that level.
Will a dehumidifier help with dry skin in winter?
No — it will make it worse. Dry skin in winter is caused by low humidity, which a dehumidifier reduces further. If your skin is dry, your home is probably already too dry. Use a humidifier instead, or add moisture to the air by hanging wet laundry or boiling water on the stove.