Match the dehumidifier size to your room, not just the brand name
The most common mistake is buying a dehumidifier that is too small for the space. A unit rated for 500 square feet will run constantly and barely keep up in a 1,000-square-foot basement, wasting electricity and wearing out faster. The right size depends on three things: the room's square footage, how wet it is, and how much moisture you need to remove each day.
Dehumidifiers are rated by how many pints of water they pull from the air per 24 hours — usually between 20 and 70 pints. A moderately damp room (one that feels clammy but has no visible mold or standing water) needs roughly one pint of removal per 500 square feet. A very damp room — one with visible mold, musty smell, or condensation on windows — needs one pint per 250 square feet. Measure your room in square feet, divide by 500 or 250, and that is your minimum pint rating.
Write down the square footage and dampness level before you shop. This number stays the same whether you are looking at a $150 unit or a $600 one.
Key Takeaways
- A dehumidifier's pint rating (how much water it removes per day) must match your room size and moisture level — roughly one pint per 500 square feet for moderately damp rooms, one pint per 250 for very damp ones.
- Refrigerant dehumidifiers work best in warm rooms above 65°F, while desiccant units work in cold basements and crawl spaces where refrigerant models fail.
- Look for a unit with a continuous drain option so you do not have to empty a bucket by hand, and check the noise level if the dehumidifier will run in a bedroom or living space.
- The humidistat (automatic shutoff when humidity drops) saves electricity and prevents the unit from running when it is no longer needed.
- Energy Star certified models use 15 percent less electricity than standard units and cost less to run over time, even if the upfront price is higher.
Refrigerant versus desiccant: which type works in your room
Refrigerant dehumidifiers are the most common and cheapest type. They work by pulling humid air over cold coils, which condenses the moisture into water that drips into a bucket or drain line. They are efficient and quiet, but they have one hard limit: they stop working well below 65°F. In a cold basement or crawl space, the coils freeze and the unit shuts down automatically to prevent damage.
Desiccant dehumidifiers use a chemical material (silica gel or similar) to absorb moisture instead of condensing it. They work in cold spaces where refrigerant models fail, and they are lighter and more portable. The trade-off is that they use more electricity, run louder, and release warm air as they work — which can actually raise the room temperature slightly. They also cost more upfront.
If your room stays above 65°F year-round, a refrigerant model will save you money. If you have a cold basement, crawl space, or garage that drops below 65°F in winter, a desiccant unit is your only option that will actually work.
Bucket versus continuous drain: how you empty the water
Every dehumidifier collects water, and you have two ways to handle it. A bucket collection system means you manually empty a tank (usually 1 to 2 gallons) when it fills up — typically once or twice a day in a very damp room. This is fine if the dehumidifier is in a basement you visit daily, but it becomes a chore if the unit is in a closet or attic.
A continuous drain option lets you attach a standard garden hose to the unit so water flows directly into a floor drain, sump pump, or outside. This costs $10 to $30 more upfront but eliminates the daily bucket emptying. If your room has a floor drain or you can run a hose to one, this is worth the extra cost. If there is no drain nearby, bucket collection is your only choice.
Check whether the unit has a drain port before you buy. Some cheaper models do not, and you cannot add one later.
Noise level matters if the dehumidifier runs in a living space
Dehumidifiers are not silent. Most run between 50 and 70 decibels — roughly the sound of a normal conversation or a dishwasher. Desiccant models tend to be louder than refrigerant ones. If the unit will run in a bedroom, office, or living room, check the decibel rating before you buy. Anything under 55 decibels is quiet enough for most people to ignore; above 65 decibels, you will notice it during the day and it may disturb sleep at night.
Manufacturers do not always list the noise level on the box, so check the product manual or spec sheet online. If the noise level is not listed anywhere, assume it is loud and look for a different model.
Humidistat and automatic shutoff save electricity
A humidistat is a built-in sensor that turns the dehumidifier off automatically when the room reaches your target humidity level — usually set between 40 and 60 percent relative humidity. Without one, the unit runs constantly even after the room is dry, wasting electricity and shortening the machine's life.
Most dehumidifiers in the $200 to $400 range have a humidistat. Cheaper models sometimes do not, so check the feature list. If you are buying a budget unit, confirm it has automatic shutoff before checkout. The cost difference is usually $20 to $50, and it pays for itself in lower electricity bills within a year.
Energy Star certification reduces long-term operating costs
An Energy Star certified dehumidifier uses about 15 percent less electricity than a standard model with the same pint rating. Over a heating or cooling season, that adds up. A unit that costs $50 more upfront but uses 15 percent less electricity will save you $10 to $20 per month in operating costs, depending on how often it runs and your local electricity rates.
If you plan to run the dehumidifier for more than a few months a year, the Energy Star label is worth paying for. If you only need it for a short season (like spring in a damp basement), the upfront savings of a non-certified model may make more sense.
Compare your top choices in a table before buying
| Feature | What to Look For | Why It Matters |
|---|---|---|
| Pint rating | Match to your room size: 1 pint per 500 sq ft (moderate damp) or 1 pint per 250 sq ft (very damp) | Too small = constant running and poor results; too large = wasted money and electricity |
| Type | Refrigerant for warm rooms (above 65°F); desiccant for cold basements and crawl spaces | Refrigerant fails in cold; desiccant uses more power but works anywhere |
| Drain option | Continuous drain if a floor drain is nearby; bucket if not | Continuous drain eliminates daily bucket emptying |
| Noise level | Under 55 dB for living spaces; up to 70 dB acceptable for basements | Loud units are annoying in bedrooms and offices |
| Humidistat | Automatic shutoff at your target humidity (40–60%) | Prevents the unit from running when the room is already dry |
| Energy Star | Certified models use 15% less electricity | Pays for itself in lower bills if you run the unit for several months |
Frequently Asked Questions
What humidity level should I aim for?
Most experts recommend keeping indoor humidity between 40 and 60 percent relative humidity. Below 40 percent can dry out skin and sinuses; above 60 percent encourages mold and dust mites. Set your humidistat to 50 percent as a starting point, then adjust up or down based on how the room feels and whether you see any mold or condensation.
Can I use a dehumidifier in a bedroom while I sleep?
Yes, but only if it is quiet enough. Look for models under 55 decibels. Many people run dehumidifiers in bedrooms overnight without problems, but a loud unit (65+ dB) will likely disturb your sleep. Check the noise rating before you buy, and consider placing it in a corner away from the bed.
How often do I need to empty the bucket?
In a moderately damp room, once or twice a day. In a very damp room, possibly more often. The exact frequency depends on the room's moisture level and the unit's pint rating. If bucket emptying becomes a burden, invest in a continuous drain option instead.
Will a dehumidifier work in a garage or unheated basement in winter?
Only if you use a desiccant model. Refrigerant dehumidifiers stop working when the temperature drops below 65°F because the coils freeze. Desiccant units work in cold spaces but use more electricity and run louder. If your garage or basement is unheated, confirm the unit is desiccant before you buy.
Do I need to do anything to maintain a dehumidifier?
Clean or replace the filter every month or two, depending on how dusty the room is. Empty the bucket regularly if you are not using continuous drain. If the unit has a humidistat, check that it is working by setting it to a lower humidity level and confirming the unit shuts off when that level is reached. Most dehumidifiers need no other maintenance.