Norpole dehumidifier, how to clean filters

Dehumidifier 2021: test, technology and criteria - the best dehumidifiers in comparison

The differences between the different types of dehumidifiers in their functionality have advantages and disadvantages, depending on the intended use. A decision in favor of the wrong model can lead to significantly higher operating costs. Before you buy a dehumidifier, you should think carefully about which selection criteria you weight and how much.

Best friends: dehumidifiers and curious cats (Photo: Mariia Boiko /

Dehumidifiers for living spaces

If you want to operate the humidifier in your home, you should opt for a compression dryer or an adsorption dryer, because only these types of construction have a sufficiently high dehumidification capacity. Depending on whether you need to dry your entire apartment or only individual rooms have too high humidity, you can further restrict your selection.

For a particularly fast drying effect, operate the dehumidifier alternately in the affected rooms. Close the intermediate doors and activate the dehumidification until the air humidity has reduced to a normal level before you move the device into the next room. If you have a large apartment with many rooms, it is advisable to ensure that the dehumidifier is mobile.

Air dehumidification in the bathroom

The bathroom is often a room with too much moisture. Since the temperatures and humidity levels in the bathroom are rather high, a Compression dryer more efficient work as a desiccant dryer and therefore preferable to it.

If you also use your bathroom to dry your clothes, you can also consider purchasing a combination device that can work as a dehumidifier and dryer at the same time.

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Dehumidifier for the bedroom

In the bedroom, on the other hand, the room temperature is usually a little lower, so that a compression dryer cannot exploit its efficiency advantage. In addition, a low noise level is crucial for overnight operation.

The chillers in compression dryers typically work louder than the fans in a dehumidifier, so an adsorption dryer is preferred for the bedroom should be used. Note, however, that the waste heat from an adsorption dryer will slightly warm the air in the bedroom.

You should therefore set the heating to a lower level in order to maintain a comfortable room climate overnight. If you are one of those people who are particularly sensitive to noise, it may even be advisable to only use the dehumidifier in the bedroom during the day and leave it switched off at night.

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Dry the basement with a dehumidifier

If you have converted your basement into living rooms and you are heating these rooms, a compression dryer is best. In unheated basements, however, the air temperature is very low, so that compression dryers cannot work very efficiently. Adsorption dryers are therefore recommended for long-term dehumidification in the basement.

In new buildings, the walls are still damp for several months and only dry out slowly. Dehumidifiers can also be used to support the drying process.

However, if the planned operation is limited in time to a short period of time, and quick drying success is more important than running costs, a compression dryer can still be useful: this is not particularly efficient at low temperatures, but can work very effectively if the dimensions are large enough. so quickly ensure drier room air.

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What drying performance should a dehumidifier have?

In order to be able to compare the drying effect of different dehumidifier models, it is usually stated how many liters of water they separate in 24 hours.

You have to compare this number with the absolute humidity that is currently present in your living space and the humidity that you are aiming for.

At a room temperature of 20 ° C and a relative humidity of 80%, the absolute water content is, for example, 15 g / m³. Your goal is to dry the room up to a relative humidity of 40%, which corresponds to 8 g / m³. With a room size of 20 m², the air volume in the room is around 50 m³, so that the absolute amount of water is currently 750 g (0.75 liters) and at 40% only 400 g (0.4 l).

With a drying capacity of 7 l in 24 hours, it would take about 72 minutes until the difference of 0.35 l is deposited [3,6]. But be careful: such a rough calculation assumes that in the meantime no further water evaporates and the humidity increases. If there are sources of moisture in the room, this drying time can be extended considerably.

How big are dehumidifiers?

Depending on the construction type and performance, the dimensions of dehumidifiers can vary widely. Peltier elements allow a compact design and are used in mobile dehumidifiers that you can put in cabinets.

Compressors and fans, on the other hand, take up more space, so that compression dryers are typically between 20 and 70 cm tall and have to be placed directly on the floor like furniture.

Especially in smaller devices and de-energized dehumidifiers, the dimensions of the housing are determined by the size of the water tank.

The larger the collecting container, the less often you have to pour out the condensate; the device is then larger. Construction dryers are equipped with drainage hoses and, in principle, do not require a water tank; here the compressor and fan make up the main part of the size.

How loud are dehumidifiers?

The question of dimensioning is not only a question of costs and power consumption, but also a consideration of the noise level: larger devices work with larger fans that can be operated at a lower speed with the same air circulation.

Larger devices are therefore often quieter in operation than smaller dehumidifiers of the same capacity [3]. As a noiseless alternative to compression dryers, you can also opt for granulate dehumidifiers that are operated without a fan.

Which extra functions are useful with a dehumidifier?

Many devices are advertised with additional features, some of which can save you a lot of stress. For security reasons, for example, a Overflow protectionthat switches off dehumidification as soon as the collecting container is full. This will prevent puddles from forming if you are out for longer than planned.

From a health point of view are a hygrometer and a Hygrostat function very useful. A hygrometer allows the current humidity in the room to be displayed, so that you can read directly on a display on the device whether the air is too humid or not.

Many devices with hygrometers also offer an automatic mode that adjusts the drying performance in order to keep the humidity constant at a set value. Such an automatic operation is also called a hygrostat.

If a dehumidifier is equipped without a hygrostat, it should at least have one timer feature. A timer, for example, allows you to switch the device on only during the day, so that you have peace and quiet at night.

If you want to use your dehumidifier consistently in very humid rooms and large amounts of water are regularly separated off, you should come with a dehumidifier Drain hose search. Instead of collecting the condensate in a container, it can be led directly into the drain via such a drainage hose, so that the annoying emptying of the water container is no longer necessary.

Dehumidifiers with powerful fans, such as those used in compression dryers, often have additional filters. In addition to simple dust filters, there are also models with activated carbon filters or ionizers, for example, to not only dry the air, but also to clean it at the same time.

This can be practical as a combination device, but there is a risk that a multi-function device is neither a good dehumidifier nor a satisfactory air purifier.

The bigger the device, the heavier it is. In order to be able to move a construction dryer with a weight of about 20 kg safely, there are models with Carrying handles or rollers at. This is important if you only use the dehumidifier seasonally or if you change its location regularly.

Operating costs of a dehumidifier

In addition to the acquisition costs for a device, you should also take into account the current expenditure for electricity consumption in your planning. The more efficiently a dehumidifier can work, the less electricity it uses. If it is operated inefficiently, the increased consumption of electricity not only causes higher costs, but also heats the room.

In general, therefore, the following advice applies: use adsorption dryers in cold rooms and compression dryers in warm rooms. In this way you can guarantee high efficiency and keep operating costs low.

However, you must note that a dehumidifier does not necessarily work continuously, but switches itself off as soon as the desired humidity is reached. For better comparability, you should therefore not relate the power consumption to the operating time, but to the amount of separated water.

A dehumidifier with a collecting container. This must be emptied regularly. (Photo: icarmen13 /

A full calculation also includes heating up the room temperature. This is particularly important if, as an alternative, you also want to examine the costs of a better ventilation system. In winter, for example, you could reduce the humidity in your home by ventilating the room regularly, but you should accept higher heating costs. When operating a dehumidifier, there are no heating costs, but you have a higher power consumption.

How do you clean a dehumidifier?

Because large amounts of air flow through the dehumidifier during operation, dust is deposited inside. In order to prevent germs from multiplying, which are then released into the air in the room, a dehumidifier must be cleaned regularly. Such a cleaning action only needs to be carried out a few times a year; depending on how often you actually use the device.

Before the actual work, you need to make sure that the dehumidifier is unplugged and cooled down. Then start wiping off dust on the outside and work your way in.

It is best to use a damp cloth that not only stirs up the dirt, but also absorbs and removes it. You can thoroughly clean cracks and holes with an old toothbrush. You can clean the collecting container for condensate with vinegar water to kill germs.

Once you have exposed the fan, you should carefully clean it with a vacuum cleaner by vacuuming the loose dust. Before assembling, you must dry all individual parts well to prevent bacteria or algae from settling.

How expensive is a dehumidifier?

The price of a dehumidifier depends heavily on the type and drying capacity. Granulate dehumidifiers are by far the simplest construction method and can cost between 5 and 50 euros. Peltier dehumidifiers can also be found for little money due to their small size.

For compression dryers, however, you usually have to pay more than 100 euros; high-performance building dryers tend to be between 300 and 400 euros.

Smaller granulate and Peltier dehumidifiers are sometimes offered in household goods stores; larger compression dryers can be found in hardware stores. You can also simply order all devices online and have them delivered directly to your home so that you do not have to carry out the transport yourself.

Nowadays, as an alternative to buying a powerful device, you can also rent construction dryers. Such a service is offered by some hardware stores or sole proprietorships in the construction industry. Renting a dehumidifier is particularly useful if you have had to work with concrete in a new building or renovation or have laid new screed.

For complete curing, the materials have to dry slowly and therefore require a low level of humidity. The drying process is over at some point after a few weeks or months, so that you no longer need a dehumidifier afterwards. In such a case, renting is cheaper than buying a new device.