Dehumidifier FAQ – Absolutely Everything You Need to Know

You’ve heard about the numerous benefits about owning a dehumidifier and now you’re considering purchasing one, but you still have lingering questions about how they work and whether or not it will be useful in your home. 

Below, you will find a list of frequently asked questions about dehumidifiers that will provide you with all the answers you need and more.



How often do you have to empty a dehumidifier?

Dehumidifiers need to be emptied at least once or twice a day, depending on the conditions of the environment in the room.

If you have any drain pipes, you can connect a drainpipe to the back of the unit and connect it to the drainpipe, or you can opt to store the drainage pipe through a window, that way you don’t have to empty the water container as often.

How long does it take for a dehumidifier to dry out a room?

When a dehumidifier is used for the first time, it may take up to 12 hours for it to start working properly. Other factors also influence its ability to work faster, depending upon the make and model of the unit. 

Some may work properly upon startup, you can find more information on this by checking out reviews and the manufacturer information.

How much moisture does a dehumidifier remove?

Most manufacturers claim that the dehumidifier collects up to 10 to 20 litres of water a day on smaller units and up to 50 litres on larger units. Most refrigerant (compressor) dehumidifiers remove between 30% and 40% of their capacity rating.  

For example, a 10-litre dehumidifier will remove between 3 and 4 litres per day and a 20 litre dehumidifier will remove between 6 and 8 litres per day. 

Having continuous drainage installed in the back of your unit also helps as this means that you can keep the water removal going without needing to keep emptying the tank – lowering the humidity level and keeping things steady.

Will one dehumidifier do the whole house?

No, one dehumidifier will not do the whole house. Most portable dehumidifiers are only useful in areas that collect the most moisture and unfortunately won’t collect from the entire house. 

If you’re living in a studio, then it will work, or if you’re opting to put it in a big open area that also connects multiple rooms without any walls. 

But If you’re experiencing excessive moisture throughout the entirety of your home, you may want to look into getting one installed that works through your heating and cooling unit. Other than that, you will need multiple units in order to get the job done.

Read Here: What Size Dehumidier Do I Need?

How much does it cost to run a dehumidifier?

Dehumidifiers are, fortunately, inexpensive to run on your electric bill. In real-time, the operating cost of an electric dehumidifier depends on the size of a room, the humidity level in the space, the number of hours you need to keep it on and the kWh rate charged by the power company. 

You can always find the energy consumption on the label on the product. If the current power rate is 15 pence/kW, an electric dehumidifier uses 4.2 pence of power per hour. Therefore, if you run it for 10 hours a day, the cost is 10 hours * 4.2 pence = 42 pence/day or about £153.30 per year.

How long should you leave a dehumidifier on?

No, it is unnecessary to run your dehumidifier all hours of the day. But it doesn’t harm the unit to do this. If the machine does not shut off at any point, then that indicates that the humidity levels are too high and you need a dehumidifier that can be left running for the majority of the day. 

The vital piece of information is that once the dehumidifier hits its rated level, say 33 litres per day, then it will not remove any more than that, no matter how many hours are left in a day. 

That is why you should opt to use a unit that has a connection port on the back for a continuous drainage pipe, that way you don’t have to empty the water tank multiple times a day.

When is the best time to use a dehumidifier?

Overnight is one of the best times to use a dehumidifier. This is partly because it will help to remove or reduce condensation in the early morning. Additionally, it makes it easier to keep an eye on the amount of water in the tank as you can just empty it when you wake up. The time of day doesn’t make a huge difference to the humidity level in the home, but it helps condensation. 

Should I run my dehumidifier in the winter?

No, you should not run your dehumidifier during the winter. The moisture levels in the air are typically lower. This can lead to dry skin, bloody noses, and chapped lips. It is unnecessary to run your dehumidifier during the winter. 

Humidifiers put the moisture back into the air, so using one of these can help with any unwanted skin problems, and can help even when someone has the common cold. Relative humidity is an important aspect to remember, and this changes seasonally.

Is the water collected by dehumidifiers safe for drinking?

No, you cannot drink the water from a dehumidifier. Drinking water that has been collected from dehumidifiers is not recommended. Dehumidifiers pull toxins from the air and you wouldn’t want to risk digesting unwanted bacteria. 

Will a dehumidifier cool a room?

Dehumidifiers can help cool the room by pulling out all of the unwanted moisture lingering in the air. It won’t work nearly as well as having an air conditioning unit running, but it will surely help reduce any heat humidity in the air and keep the room temperature a little lower. 

Best place for a dehumidifier in the house?

The best place for your dehumidifier is in the room you need it the most. This can include bathrooms, bedrooms, kitchens, basements, or crawl spaces. Areas with the most moisture and high humidity present can lead to mildew and mould forming, which is why dehumidifiers are needed.

How noisy is a dehumidifier?

The noise levels produced by a dehumidifier greatly depend on the model that you choose and any settings that come with it. Some are advertised as being silent, which means that they tend to be quiet enough that you can have them running while you sleep.

Will a dehumidifier kill mould?

Unfortunately, mould stays dormant in the air and on surfaces, dehumidifiers do not kill mould but can prevent it from occurring by reduced humidity. If you have a mould problem in your home, don’t wait. Mould spreads as long as it has a water source, and can lead to respiratory illnesses.

Can a dehumidifier help control or relieve my allergy symptoms?

No, a dehumidifier is not meant for allergies. It can relieve symptoms in the sense that it can help to reduce dust mites and trap mould and mildew. However, for true allergy relief you will want an air purifier, which you can find in our detailed buying guide.

Does a dehumidifier clean the air?

No,a dehumidifier doesn’t clean the air. Dehumidifiers can help reduce odors that come from mildew and mould inside the home. Running a dehumidifier helps reduce dust in your home, so you won’t have to clean as often. 

If you want the air to be cleaned, you are best off investing in an air purifier, which is specially designed for the task. 

Can I leave my windows open while using a dehumidifier?

Opening your windows while running your dehumidifier is unnecessary. Outside temperatures tend to travel into open spaces through cracks in doorways and leaving your windows open. 

Your unit would be constantly running to get rid of the moisture brought in from outside. Covering windows, and cracks can ultimately reduce the amount of humidity in a room.

What are the benefits of owning a dehumidifier?

There are several benefits to owning a dehumidifier. Dehumidifiers help with allergies and can reduce dust mites lingering in the air. It can also help remove any pests that are brought in due to low humidity, and can improve your overall comfort inside the home.

To Conclude

Hopefully, we have been able to answer any questions you have about using a dehumidifier and how they can help you to create a more comfortable living space. 

If you’re looking to purchase a dehumidifier for your home, we have reviewed a fantastic selection of them- all designed to reduce humidity and that you know come from trusted and reliable brands.

Last Updated on February 25, 2021 by Gemma Tyler Protection Status