Yes, a dehumidifier raises room temperature, but usually by a small amount

A dehumidifier does make a room warmer—it's not a side effect you're imagining. When a dehumidifier pulls moisture out of the air, it releases heat as a byproduct. The warm air it exhausts back into the room is slightly hotter than the air it pulled in. In most homes, you'll notice a temperature rise of 1 to 3 degrees Fahrenheit, though the exact amount depends on how hard the unit is working and how much moisture it's removing.

This happens because of how dehumidifiers work at the mechanical level. The unit cools air to condense water vapor into liquid, then warms that air back up before releasing it. That warming step is where the heat enters your room. It's the same reason your refrigerator makes your kitchen warmer—the heat has to go somewhere, and in a dehumidifier, it goes back into the space you're trying to dry.

Key Takeaways

  • Dehumidifiers raise room temperature by 1 to 3 degrees Fahrenheit on average because they release heat as they remove moisture from the air.
  • The amount of warming depends on the dehumidifier's size, how often it runs, and how much moisture is in the air—larger units working harder produce more heat.
  • In summer, the warming effect is usually offset by the comfort gain from lower humidity, which makes air feel cooler even if the thermometer reads higher.
  • In winter, when you're already heating your home, a dehumidifier's added warmth can actually reduce your heating costs slightly.
  • If room temperature is a concern, positioning the dehumidifier away from your thermostat prevents it from triggering your air conditioner to run longer.

Why the temperature increase happens

The warming occurs because of the dehumidifier's refrigeration cycle. Inside the unit, a compressor circulates refrigerant through coils. Air from your room passes over cold coils, where water vapor condenses into liquid and drips into a collection tank or drain line. That liquid water is removed, but the air itself still needs to exit the unit. Before it does, the dehumidifier passes it over warm coils (heated by the compressor's work), raising its temperature back up. This warmed, now-dry air is what blows back into your room.

The heat energy doesn't appear from nowhere—it comes from the electrical power the dehumidifier consumes. Some of that energy goes into the work of removing moisture; the rest becomes heat. In a closed room, all of that heat stays inside, so the room temperature climbs. The harder the dehumidifier works (the more moisture it's pulling out), the more heat it generates.

How much warmer your room actually gets

Most dehumidifiers raise room temperature by 1 to 3 degrees Fahrenheit during normal operation. A small, low-capacity unit running occasionally might add only 1 degree. A large, high-capacity unit running continuously in a very humid space could add 3 degrees or slightly more. The relationship is roughly proportional: a unit removing 30 pints of water per day generates more heat than one removing 20 pints.

The warming is also temporary and localized at first. The warm air exits the dehumidifier and mixes with the rest of the room's air. In a small bedroom, you might feel the difference within 30 minutes. In a larger space or a whole house, the effect spreads out and becomes less noticeable. If your dehumidifier is in a basement or utility room rather than your main living space, you may not perceive any temperature change at all.

Summer humidity versus temperature: which matters more

In summer, the 1 to 3 degree temperature increase is usually a worthwhile trade-off. Humid air feels hotter and stickier than dry air at the same temperature. A room at 76 degrees with 70% humidity feels significantly warmer and more uncomfortable than a room at 78 degrees with 40% humidity. By running a dehumidifier, you're trading a small rise in actual temperature for a much larger drop in perceived temperature and real comfort.

This is why many people report feeling cooler after turning on a dehumidifier, even though the thermometer shows a higher number. The humidity reduction is the dominant effect. Your skin can evaporate sweat more easily in dry air, and that evaporation is what cools your body. In humid conditions, sweat doesn't evaporate well, so you feel hot and clammy no matter what the air temperature is.

Winter operation and heating costs

In winter, a dehumidifier's heat output can actually work in your favor. If you're running a dehumidifier to control moisture in a basement or to manage indoor humidity during the heating season, the warmth it generates reduces the load on your furnace or heat pump. Your heating system doesn't have to work as hard to maintain your target temperature, which can lower your heating costs slightly.

The savings are modest—usually a few dollars per month—but they're real. A dehumidifier using 700 watts of electricity generates roughly 2,400 BTU of heat per hour. If your furnace would have produced that same heat anyway, you've straightforward shifted the source from your heating system to the dehumidifier. Since dehumidifiers are generally more efficient at producing heat than electric resistance heating, the net effect is a small cost reduction.

Positioning your dehumidifier to minimize temperature concerns

If the temperature increase bothers you, placement matters. Never position a dehumidifier directly in front of your thermostat. When the warm exhaust air hits the thermostat, the thermostat reads a higher temperature than the rest of the room and may signal your air conditioner to run longer than necessary. This wastes energy and can make your cooling costs higher, not lower.

Instead, place the dehumidifier in a corner or along a wall away from the thermostat and away from air vents. This allows the warm exhaust to mix with the room's air gradually rather than creating a hot spot near your temperature sensor. In a basement, placing the unit near a wall or in a utility closet is ideal because the heat has more space to dissipate before reaching living areas.

When to call a professional about temperature or humidity

If your room temperature is rising more than 5 degrees with a dehumidifier running, the unit may be oversized for the space or may be malfunctioning. A dehumidifier that's too large will cycle on and off frequently, and each startup generates a burst of heat. Have the unit serviced to check that the compressor and coils are clean and functioning normally.

If humidity levels aren't dropping even with the dehumidifier running, the problem may be outside the dehumidifier's control—a water leak, poor ventilation, or a basement that's below grade and constantly absorbing groundwater. These situations require a plumber or moisture specialist to diagnose and fix the source, not just treat the symptom with a dehumidifier.

Frequently Asked Questions

Will a dehumidifier make my air conditioner work harder?

Only if the dehumidifier's exhaust air blows directly at your thermostat. If the unit is positioned away from the thermostat, the small temperature rise (1 to 3 degrees) is usually offset by the humidity reduction, and your air conditioner may actually run less because the air feels more comfortable. Keep the dehumidifier away from vents and thermostats to avoid triggering unnecessary cooling cycles.

Can I use a dehumidifier to heat my room instead of the furnace?

No. A dehumidifier generates only about 2,400 BTU of heat per hour, which is far too little to heat a room. A typical space heater produces 5,000 BTU or more. Dehumidifiers are designed to remove moisture, and the heat is straightforward a side effect. Use a proper heating source for warmth and a dehumidifier only for moisture control.

Does a dehumidifier use a lot of electricity?

Most dehumidifiers use 300 to 700 watts, depending on size and capacity. Running one continuously costs roughly $10 to $25 per month in electricity, varying by your local rates. The cost is usually justified by the comfort and health benefits of lower humidity, especially in basements or humid climates.

Why does my dehumidifier feel hot to the touch?

The exhaust vents and the back of the unit get warm because that's where the heated, dried air exits. This is normal. The unit is designed to handle this temperature. Never block the exhaust vents or place the dehumidifier against a wall or furniture, as this can trap heat and reduce efficiency.