Dehumidifier throws off hot air making the room very warm. Is that normal?

A heat pump is an air conditioner that reverses its refrigerant flow. In the cooling mode, the evaporator is cold to the room and its condenser is hot. In the heating mode, a valve reverses the refrigerant flow and makes the evaporator warm and the condenser cold.

It is normal for a dehumidifier to discharge warm air. A dehumidifier is really an air conditioner - a fan blows humid room air across a cold fin coil that causes the moisture to condense on it and drip into a container - thus cooling AND dehumidifying the air. The cool air is blown over the warm coil and discharged out the back. A dehumidifier WILL normally increase the temperature of the room it is in.
You can do the same thing with sitting an A/C unit on a stool in a room. Room air will be drawn in, cold air will come out the front, hot air out the back and water will drip on the floor. And, the room will get hotter, due to what is called "heat of compression" even though you're running an A/C unit.

If the room air is less than the set air, then there is no water in the bucket, because there is almost no humidity in the air. If it is winter, there is likely not enough humidity in the air to have water collect in the bucket. A dehumidifier will only pick up humidity out of warm air. If you are running a dehumidifier in your basement in the winter, the room may be damp, but too cold for the dehumidifier to pull out the humidity. Try running the unit in the bathroom after having a hot shower without the bathroom fan on. If working correctly the unit should draw water.

Other things that can cause problems: 1.Check to see if the air filter is dirty and/or blocked. 2. The room temperature might be too low, (below 60 degrees Fahrenheit ) 3. Check to make sure that there is no obstruction to the unit that might be causing poor airflow circulation.

Hope this helps you to troubleshoot & solve the problem.

if you want hot air the you need a humidifier, it puts warm moist air into the room. used to put moisture in the air if your running a wood stove

a dehumidifier is basically the same thing as an air conditioner but both coils (condenser and evaporator) are in the same unit meaning a dehumidifier exhaust warm air in the same room it is in. running a dehumidifier would make an air conditioner run more because of the warm exhaust, but you are correct, when you run an air conditioner it acts like a dehumidifier and dries the air. as far as saving energy it all depends on the size of the AC and dehumidifier and the size of the room. If you want warm dry air use a dehumidifier if you want cool dry air run the AC but not both.

Humidity, [Swetting] until the Room is totally dried out.Remember you are also drawing off infloor and underfloor dampness too.
Regards,DT

Here is Danby's official response to a similar question on their FAQ page for Dehumidifiers:
https://www.danby.com/faqs.php?cat=12

Q) When the dehumidifier is operating, is it normal for the expelled air to be quite warm? We find that the dehumidifier is warming up the room noticeably (a finished basement).

A) The warm air that is being expelled from your dehumidifier is normal. When the unit is dehumidifying the compressor is working which causes the compressor to become quite hot. In order to avoid having the compressor overheat, air is drawn by the compressor at a rapid rate and the heat is then transferred to the air which must be expelled from the unit. The warm air will stop shortly after the unit has reached the desired humidity. This warm air should not change your room temperature by more than a degree or two.

Hi,
If you are having problems with your dehumidifier freezing up them here are a few things that you can check and also a few things that may help you.

First check the ambient temperature of the room at the level of the dehumidifier. If it is below 65 degrees and you do not have a special low temperature dehumidifier then you are asking for trouble. Most units are only designed to work in temperature 65 or higher and will freeze if they are working at lower temperatures. Some even will not work well below 68 degrees F.

Many dehumidifiers will shut off when the coil starts to freeze to let them thaw, then they will restart when the coil is warm enough again. This can take an hour or so. Some will not shut down the compressor and when the dehumidifier coil starts to freeze it reduces the air flow and only compounds the problem.

Check the air flow over the coil. If the coil becomes dirty or the fan motor stops or even slows down a bit, you will get freezing. The dehumidifier is very dependent upon the proper amount of air going over the coil to keep the coil warm enough to not freeze. Any restriction will cause problems.

The final and worst thing that can happen is for your dehumidification unit is to develop a slight leak in the refrigeration system. This will cause the coils to run even colder then they would normally and this will create the same problems. If everything else check out then you may have to have the refrigeration system checked by a professional. The problem with this is that many of these units only cost a few hundred dollars and a service call can soon add up to more then the unit is worth.

Some things that you can do to help out a dehumidifier that is freezing up are:

Raise the temperature of the room and provide a bit of heat for the room as the dehumidifier is actually a very small A/C unit.
Raise the dehumidifier up off of the floor… the air is usually warmer when you go higher up in the room, hot air rises.
Clean the coils off so that the air can flow through them easier and keep them warmer.
Make sure that the fan motor bearings are oiled and that the fan is running freely. Even a tiny bit of resistance will slow the fan enough to make a difference.


By checking all these things out and making some small changes you maybe able to make your dehumidifier work much more effectively.

Take care

Most dehumidifiers need warmer air to work properly. The temperature in a basement is usually 60 - 65F; too cool for standard models. You could buy a "basement" dehumidifier. They're designed to work at lower temperatures; some as low as 40 F. Costs are about the same as a standard dehumidifier; you just have to find it.

For a cheap fix, try this; it seems to be working for me.

Since the condensate coil (the one icing up) is cold, the air entering it is too cool and the condensate frosts up the coil. Additional condensate freezes to the frost and before you know it, you've got a block of ice. Since the air coming out of the front is very warm take a large piece of cardboard around 6' x 3') and form a V. Placed it in front of the dehumidifier so it channels some of the warm air back to the rear where it warms the moist air up before it hits the cooling fins. It's helped keep the ice down.

If you want something attractive, any screen that redirects some of the air back to the rear will work. Just leave the top open so it doesn't get too hot and the some of the drier air gets out into the room.