Does A Dehumidifier Blow Hot Air (Or Cold)?

Dehumidifiers work by using a blower to extract air from within a home and force it through components that help to remove moisture before blowing it back out into the room.

There can be a change in temperature of the air as the humidity is lowered by passing through a dehumidifier.

Dehumidifiers typically blow out air that is mildly warm to warm as part of normal operation. The temperature of the air leaving a dehumidifier can depending on the type, with desiccant dehumidifiers typically blowing out warmer air compared to refrigerant types.

Our own dehumidifier is the desiccant type, and while it blows out cooler-feeling air after first starting up, the air soon becomes noticeably warmer not long after it’s started working.

Feeling the warm air blow out of our dehumidifier

We discuss why dehumidifiers typically blow out warming feeling air in more detail below, including why some types can blow air that’s warmer than others.

How Does A Dehumidifier Work?

Air releases water when it is getting cooler.

The principle of how a dehumidifier works is therefore: it needs to cool down air to release and collect the moisture and thus lower the relative humidity:

  • A dehumidifier sucks air from a room.
  • It drives the air through the cooling system that reduces the air temperature.
  • Moisture condenses on the cooling coils for refrigerant types (or collected by a desiccant wheel for desiccant types) and drops into a tray.
  • A separate set of condensers warm the air back to the temperature it was when it entered the dehumidifier

A typical dehumidifier cooling system resembles a very small refrigerator but with pumps and compressors. Everything is made to work very quickly, so the machine needs to have a lot of cooling power to dehumidify and release air quickly- only then will moisture be released from the air faster.

Thus, it needs to reduce air temperature quickly.

After being chilled down, the air then goes through a heating system.

It will heat air to roughly the same temperature (but roughly is the keyword here).

Dehumidified air of the same temperature feels slightly warmer than the air with a higher level of humidity.

Drier, warmer air being blown out

What If My Dehumidifier Does Not Produce Heat?

Refrigerant dehumidifiers typically blow out less warm-feeling air compared to desiccant dehumidifiers because the air doesn’t first need to be cooled to extract the moisture.

It can be normal for a dehumidifier to blow hot air.

This is why a dehumidifier can make a room slightly warmer over time through use.

However, if your device does not, it’s not a reason for worry.

Some dehumidifiers are designed and built to extract moisture differently and will release air that is roughly the same temperature, or even slightly colder-feeling depending in the climate you’re currently in.

How Hot The Air From A Dehumidifier Should Be?

The temperature of the air that comes out of a dehumidifier can be different from the temperature of the air that comes into a dehumidifier.

It depends on the make and model of a dehumidifier, but can also depend on the air temperature in the room.

Dehumidifiers will heat the air to a temperature that resembles the temperature of the air that comes into the dehumidifier.

  • If the room is 70 degrees (21 degrees Celsius), you will feel the air coming out from a dehumidifier slightly warmer.
  • If your room is warmer than roughly 80 degrees Fahrenheit (27 degrees Celsius), you will barely notice any heat coming out of a dehumidifier because the higher the temperature is in the room, the less difference you are going to notice.
  • If your room is very warm, let’s say, 100 degrees Fahrenheit (38 degrees Celsius), then your room will become slightly cooler.

In normal circumstances, dehumidifiers make air just a few degrees Fahrenheit (or slightly higher than 1-2 degrees Celsius) hotter.

Unless your dehumidifier is working in a very small room, the general temperature of that room should not go much higher.

We notice that the room we’re using our dehumidifier in gets progressively hotter throughout the day because it’s constantly blowing warm air.

Dehumidifier Drying Washing
The warm air blown out by our dehumidifier helps to dry our washing faster

If you’ve started to notice a significant increase in temperature while a dehumidifier is in operation, your device could be malfunctioning.

Can A Dehumidifier Produce Too Much Heat?

Unless a dehumidifier is being used on a heater mode, it shouldn’t be producing too much heat.

Our dehumidifier can be used as a standalone heater and produces very warm air

If you still think that your dehumidifier produces too much hot air, there might be a problem with the cooling system like refrigeration inside is not working.

  • Check for possible minor fixes like if fans are not working properly or if the water tray is not full.
  • Check if your dehumidifier is slightly covered with ice. It can signal coolant leakage and requires maintenance
  • If it is still within a warranty service period, use the company’s customer service.
  • If it is out of warranty, see a local electrical service.
  • If it has been out of warranty for a very long time, it just might be time for your dehumidifier to go.

Do not open a device yourself in any case. It will void the warranty and can be dangerous. Your actions with a dehumidifier should not go past the point of normal user maintenance like emptying a moisture tray. Do not try to open the cooling system – it is complicated and will require attention from a specialist.

Check Humidity Level

Another signal that your dehumidifier is malfunctioning is that it does not take away enough humidity from the air.

If you do not have a thermometer with a humidity level check, consider getting one, and check on your dehumidifier from time to time. If your humidity is not on the level that you have set on your device and the dehumidifier produces too much heat at the same time, that can be a reason for worry.

On its own, higher humidity than expected does not always indicate malfunctioning.

Normal humidity levels vary from 30 to 60 percent and slightly less in colder climates during heating seasons. If you do not reach that level or the level in your settings, try placing the dehumidifier differently so that fans are not obstructed, closing windows and doors, and keeping your device clean and empty of water.

Does A Dehumidifier Blow Hot Or Cold Air?

A dehumidifier will typically blow out slightly warmer air than room temperature.

Usually, the air will be blown through a series of fans, cooling, and heating systems to soak out moisture for air, then it gets released back into a room with less water and a slightly higher temperature.

If your dehumidifier blows cooler air: either you have a device that works differently, or your room is too hot.

However, if your dehumidifier blows out air that is significantly hotter, it can be a signal that it needs maintenance.

Further Reading

Does A Dehumidifier Need To Be Serviced And Maintained?

Does A Dehumidifier Actually Work?

Does A Dehumidifier Help With Dust?

Can You Leave A Dehumidifier Unattended?