A dehumidifier does not cool a room down — it may make it feel slightly warmer
A dehumidifier removes moisture from the air but does not lower the temperature. In fact, the machine produces heat as a byproduct of its operation, which can raise the room temperature by a degree or two. If you are looking to cool a room, a dehumidifier is not the tool for that job. An air conditioner removes both heat and moisture; a dehumidifier removes only moisture.
The confusion often comes from the fact that dry air can feel more comfortable than humid air at the same temperature. When humidity is high, sweat on your skin does not evaporate as easily, so you feel hotter and stickier. A dehumidifier will reduce that sticky feeling, but the actual air temperature stays the same or rises slightly.
Key Takeaways
- Dehumidifiers remove moisture but produce heat, so they may raise room temperature by one to two degrees.
- Dry air feels more comfortable than humid air at the same temperature because sweat evaporates more easily.
- If your goal is to lower room temperature, you need an air conditioner or a fan, not a dehumidifier.
- A dehumidifier works best in spaces where humidity is the main problem, not heat.
- Running a dehumidifier and an air conditioner together can reduce the air conditioner's workload and lower energy costs.
Why a dehumidifier produces heat instead of cooling
Dehumidifiers work by pulling moist air over cold coils, which causes water to condense and drip into a tank or drain. The air that comes back out of the machine is warm because the dehumidifier has removed the moisture but kept the heat. The compressor and motor inside also generate their own heat as they run.
This is different from an air conditioner, which cools the air before releasing it back into the room. An air conditioner uses refrigerant to absorb heat from indoor air and move that heat outside. A dehumidifier has no way to move heat out of the room — it only moves moisture out.
When dry air feels cooler even though it is not
Your body cools itself by sweating and then letting that sweat evaporate from your skin. When the air is humid, evaporation happens slowly, so sweat stays on your skin longer and you feel hot and uncomfortable. When the air is dry, sweat evaporates quickly, and your body feels cooler even if the thermometer reads the same temperature.
This is why a room at 75 degrees and 30 percent humidity feels more comfortable than a room at 75 degrees and 70 percent humidity. The dehumidifier creates that first condition by removing moisture, but it does not change the 75-degree reading. Your comfort improves, but the room temperature does not drop.
Using a dehumidifier alongside an air conditioner
If you run a dehumidifier and an air conditioner in the same space, the air conditioner does not have to work as hard to remove moisture. This can lower your energy costs because the air conditioner can focus on cooling rather than dehumidifying. However, the dehumidifier itself uses electricity, so the total energy use may not decrease — it depends on how efficient each machine is and how much moisture is in the air.
In very humid climates, this combination can make sense. The air conditioner cools the air, and the dehumidifier removes extra moisture that the air conditioner cannot handle efficiently. In drier climates, running both machines together is usually wasteful.
Situations where a dehumidifier is the right choice
A dehumidifier is useful when humidity is the problem but temperature is not. Basements often stay cool but feel damp and musty — a dehumidifier can fix that without cooling the space further. Bathrooms after a shower, laundry rooms, and crawl spaces are other places where moisture is the main issue.
A dehumidifier is also helpful in winter, when an air conditioner is not running but indoor humidity stays high from cooking, showers, and drying clothes. Removing that moisture can prevent mold growth and make the space feel fresher without wasting energy on cooling.
Better tools if your goal is to cool a room
An air conditioner — whether a window unit, portable unit, or central system — is the only tool that actually lowers room temperature. A fan does not cool the air either, but it moves air across your skin, which makes you feel cooler through the same evaporation effect that a dehumidifier creates. A fan uses far less electricity than an air conditioner or dehumidifier.
If you want to cool a room and reduce humidity at the same time, an air conditioner does both. If you want to cool a room and have no air conditioner, a fan is your cheapest option. If you want to reduce humidity without cooling, a dehumidifier is the right choice — just understand that it may make the room slightly warmer.
Frequently Asked Questions
Will a dehumidifier help if my air conditioner is running?
Yes, it can reduce the load on your air conditioner, especially in very humid climates. The air conditioner will not have to work as hard to remove moisture, which may lower your energy bill. However, the dehumidifier itself uses power, so the total savings depend on the efficiency of both machines and how humid your space is.
Can I use a dehumidifier instead of an air conditioner?
No. A dehumidifier removes moisture but does not lower temperature — it may even raise it slightly. If you need to cool a room, you need an air conditioner or a fan. A dehumidifier is only a substitute if humidity is your problem and temperature is not.
Why does the air from my dehumidifier feel warm?
The machine pulls moist air over cold coils to remove water, then releases that air back into the room. The air has lost moisture but kept its heat, and the compressor inside generates additional warmth. This is why dehumidifiers can raise room temperature by one to two degrees.
Is it normal for a room to feel warmer after I turn on a dehumidifier?
Yes. The machine produces heat as it runs, so the room temperature may rise slightly. However, the air will feel less sticky and more comfortable because the moisture is gone. If the warmth bothers you, pair the dehumidifier with a fan to move air around.