A dehumidifier will not lower the actual temperature, but it will make the air feel cooler on your skin
A dehumidifier removes moisture from the air but does not change the thermometer reading. If your room is 75°F, it will stay 75°F. However, humidity affects how your body perceives temperature. When moisture in the air drops, sweat on your skin evaporates more easily, and you feel cooler even though the room temperature has not changed. This is why a humid 75°F feels sticky and uncomfortable, while a dry 75°F feels pleasant.
The difference is real but limited. A dehumidifier can make a room feel 2 to 4 degrees cooler than it actually is, depending on how much moisture you remove. In very humid climates — places where humidity stays above 70 percent — this effect is noticeable. In drier climates, the change is subtle because there is already less moisture to remove.
If you want the room to actually be cooler, you need an air conditioner, not a dehumidifier. A dehumidifier uses electricity to pull water out of the air, and that process generates heat as a byproduct. In a sealed room, a dehumidifier may actually raise the temperature slightly while making the air feel less sticky.
Key Takeaways
- A dehumidifier does not lower room temperature but makes the air feel cooler by allowing sweat to evaporate faster from your skin.
- The perceived cooling effect is strongest in humid climates where humidity exceeds 70 percent and weakest in already-dry air.
- A dehumidifier generates heat as it operates, so in a sealed room it may slightly raise the actual temperature while improving comfort.
- If you need the room to actually be cooler, an air conditioner is the right tool; a dehumidifier is for comfort and moisture control.
How humidity affects what temperature feels like
Your body cools itself by sweating. When sweat evaporates from your skin, it carries heat away and you feel cooler. Humidity blocks that evaporation. When the air is already saturated with moisture, sweat stays on your skin instead of drying, and your body cannot shed heat efficiently. This is why 80°F at 90 percent humidity feels unbearable, while 80°F at 30 percent humidity feels manageable.
Removing humidity restores the evaporation process. A dehumidifier pulls water vapor out of the air, lowering the relative humidity. As humidity drops, sweat evaporates faster, and your body's cooling system works again. The room temperature stays the same, but you feel significantly more comfortable.
This effect is strongest when humidity is very high. In a basement or bathroom where humidity regularly hits 80 to 90 percent, dropping it to 50 percent will make a noticeable difference in how the room feels. In a room that is already at 40 percent humidity, a dehumidifier will have little effect on comfort because there is not much moisture to remove.
Why a dehumidifier does not cool the actual air
A dehumidifier works by pulling air across cold coils, similar to how an air conditioner works. Water condenses on those coils and drips into a tank or drain. The dried air is then pushed back into the room. This process removes moisture but does not remove heat from the room overall.
In fact, a dehumidifier generates heat. The compressor and motor that run the unit produce warmth, and that heat is released into the room along with the dried air. In a small, sealed space, this can actually raise the room temperature by 1 to 3 degrees while the humidity drops. You feel cooler because of lower humidity, but the thermometer may show the room is slightly warmer than before.
This is why a dehumidifier is not a substitute for air conditioning. If your goal is to lower the actual temperature, you need a cooling system that removes heat from the room and vents it outside. An air conditioner does both: it removes heat and moisture. A dehumidifier only removes moisture.
When a dehumidifier will noticeably improve comfort
A dehumidifier works best in climates or seasons where humidity is high but temperature is moderate. Summer in the Southeast, the Midwest during spring, and basements year-round are ideal situations. In these settings, humidity often exceeds 60 percent, and bringing it down to 40 to 50 percent creates a real comfort gain without requiring air conditioning.
A dehumidifier is also useful in air-conditioned spaces where the AC is not running. If you use your air conditioner sparingly to save energy, a dehumidifier can keep a room comfortable on mild days when the temperature is acceptable but the air is damp. You get comfort without the energy cost of cooling.
In very hot climates where temperature is the main problem, a dehumidifier alone will not solve your comfort issue. Phoenix in summer is dry and hot; a dehumidifier will do almost nothing because there is little moisture to remove. Miami in summer is humid and hot; a dehumidifier will help with the humidity but not the heat. In Miami, you need air conditioning.
The difference between perceived temperature and actual temperature
Weather services and thermostats report actual temperature. Your body experiences apparent temperature, which combines actual temperature, humidity, wind, and sun exposure. On a humid day, the apparent temperature is much higher than the thermometer reading. On a dry day, it is lower.
A dehumidifier shifts your apparent temperature downward by removing the humidity component. If your room is 75°F and 80 percent humidity, the apparent temperature might feel like 82°F. If you lower the humidity to 50 percent, the apparent temperature might feel like 77°F. The actual temperature is still 75°F, but your body perceives it as cooler.
This is a real comfort improvement, but it has limits. A dehumidifier cannot make 95°F feel cool. It can make 95°F feel slightly less oppressive, but you will still be hot. For true cooling in hot weather, you need an air conditioner.
Dehumidifier size and how much moisture it removes
A dehumidifier's capacity is measured in pints per day — the amount of water it removes from the air in 24 hours. A small unit removes 30 to 50 pints per day. A large unit removes 70 pints per day or more. The more moisture a dehumidifier removes, the more noticeable the comfort improvement.
A unit that is too small for your space will run constantly and remove moisture slowly. You will feel a gradual improvement in comfort, but it may take days or weeks to reach the humidity level where you notice a real difference. A unit sized correctly for your room will bring humidity down faster, and you will feel the benefit sooner.
Room size, starting humidity, and how sealed the space is all affect how quickly a dehumidifier works. A 50-pint unit in a 200-square-foot bedroom with high humidity may bring comfort improvement within a day or two. The same unit in a 500-square-foot open-plan space may take a week.
Energy cost of running a dehumidifier versus air conditioning
A dehumidifier uses less electricity than an air conditioner. A typical 50-pint dehumidifier uses 600 to 800 watts. A window air conditioner uses 1000 to 1500 watts. Running a dehumidifier 12 hours a day costs roughly $15 to $25 per month in electricity. Running an air conditioner the same amount costs $30 to $50 per month.
If your goal is comfort on mild, humid days without the cost of air conditioning, a dehumidifier is the more economical choice. You get a noticeable comfort improvement for less money. On hot days, however, you will need the air conditioner anyway, so the dehumidifier becomes an additional cost rather than a replacement.
Some people run both: they use air conditioning on hot days and a dehumidifier on mild but humid days. This approach balances comfort and cost, though it requires space for two appliances.
Frequently Asked Questions
Can I use a dehumidifier instead of air conditioning?
Only if your main problem is humidity, not heat. If the room temperature is acceptable but the air feels sticky, a dehumidifier will improve comfort. If the room is hot, you need air conditioning. Many people use both: air conditioning on hot days and a dehumidifier on mild but humid days.
Will a dehumidifier make my electric bill go up a lot?
A dehumidifier uses less electricity than an air conditioner — roughly 600 to 800 watts compared to 1000 to 1500 watts. Running one 12 hours daily adds about $15 to $25 per month to your bill, depending on your local electricity rates.
How long does it take to feel cooler after turning on a dehumidifier?
You may feel a slight difference within an hour or two as the unit begins removing moisture. A noticeable comfort improvement usually takes 12 to 48 hours, depending on the room size, starting humidity, and dehumidifier capacity. Very humid spaces may take several days to reach comfortable humidity levels.
Does a dehumidifier work in a room with air conditioning?
Yes, but usually not necessary. Air conditioners remove both heat and moisture, so a dehumidifier adds little benefit in an air-conditioned room. The exception is if your air conditioner is not removing enough moisture — some units in very humid climates struggle to keep humidity below 60 percent, and a dehumidifier can help in that case.
What humidity level should I aim for?
Most people feel comfortable between 30 and 50 percent relative humidity. Below 30 percent, the air feels dry and can irritate your skin and sinuses. Above 60 percent, the air feels sticky and mold growth becomes more likely. A dehumidifier should bring your space into that 40 to 50 percent range for best comfort.