Our lab tests cover some of the most important tasks a dehumidifier performs (including their water extraction, energy efficiency, humidistat function) as well as how easy they are to use and the noise they produce. But there are some things our extensive testing can't reveal – the most common dehumidifier faults is one of them. There are many benefits to having a dehumidifier in your home. One of the essential elementsof comfort at home is to have a well ventilated living space that is free from allergen, mold and mildew and does not encourage the growth of dust mites.

If your dehumidifier is less than six months old and you experience problems such as a function failure or a complete failure, see our faulty goods advice guides to see how you can take action. In our survey, 18% of people had the dehumidifier replaced by the manufacturer or retailer, while 14% had the dehumidifier repaired under the manufacturer warranty. A newly built home may be damp if the water used when building it is still drying out– for example, in the plaster on the walls. Excess moisture indoors can also be caused by condensation.The extraction rate you’re looking for really depends on where you live and what you’re using the dehumidifier for, but in the UK, you can aim for one that extracts between 1-2.5L a day. A compressor dehumidifier is the most common type in the UK as it works best in higher temperatures, such as in a heated home.

Dehumidifiers can use a lot of energy, especially if used inefficiently. The electricity required to power a dehumidifier can be generated from a mixture of burning fossil fuels, renewables, gas and nuclear. But as this is mixed up in the grid, you can’t guarantee it’s coming from a renewable energy source. That said, dehumidifiers aren’t the most stylish-looking devices. Hence, you’re unlikely to want a large unit sitting in the middle of your lounge but still think carefully about its placement. If the moisture comes from a leaky window or front door, place it near them. If you have a serious damp or condensation problem, it’s worth buying a model with a bigger tank so that it keeps working all night. How to choose the best dehumidifier for your homeThere are two types of dehumidifier that you will need to choose between - desiccant and refrigerant. Desiccant dehumidifiers use a material that absorbs moisture and condenses it, while refrigerant dehumidifiers have a cool metal plate that converts the air into liquid as it works. While the former is capable of working in colder temperatures, it also uses more energy.

litres – large capacity. A sensible choice if you have a lot of moisture that you need to get rid of fast. For example, clearing up after a flood or dealing with lots of water in the air through drying laundry indoors. Noise: A dehumidifier's noise levels can fall between 34dB to 60dB - 34dB being a whisper and 60dB being the same as a normal conversation. If you choose to run your dehumidifier at a lower fan speed, it will make less noise but may be less effective. Think about where you are using it and whether it will disturb you. If you're not yet a member, join Which? to get instant access to the following dehumidifier brand verdicts: Argos, Blyss, Challenge, DeLonghi, Dimplex, Ebac, EcoAir, Electriq, Logik, Meaco and Pro Breeze. The main factor to consider is the space you want to dehumidify . In general, for a bedroom an 11 or 13 litre dehumidifier will be sufficient, for garages, basements and larger rooms a 25lire would be idealExtraction amount: It is essential to consider the maximum amount of moisture your dehumidifier can extract daily. It can range from anywhere from 500ml to upwards of 30 litres. Small units are fine for occasional use or a small area, such as a cupboard or study. Around 12 litres is suitable for a small flat, medium-sized room or a mild damp problem. Up to 16 litres is best for a larger room or one used regularly for washing or cooking, and units with a capacity of up to 20/30 litres can be used to dehumidify whole homes. Unfortunately, 24% had to stop using their dehumidifier once it had a fault and disposed of it. Head to our dehumidifier guide to find out how to dispose of one. How we calculate the best and worst dehumidifier brands A dehumidifier's size or capacity describes how many litres of water it's able to extract from the air each day (which is different to the water tank capacity). Dehumidifiers for homes range in capacity from seven to 25 litres. To discover the dehumidifier brands you can depend on, we asked 6,997 Which? Connect panel members and 3,003 members of the general public to tell us how happy they are with their dehumidifier, whether they had experienced any problems with it and whether they would recommend the brand.

Humidity levels: Relative humidity (RH) should sit between 30 to 60%, and most models have a built-in humidistat to keep the room at your chosen level. Devices with an auto-setting monitor adjust the moisture levels in the room, which can save on electricity. Night mode Dehumidifiers can be noisy machines. If you intend to run it at night, look for a model with a 'night mode' or a 'silent mode'. If you wake up in the morning and your bedroom has water droplets on the inside of the glass, this is an indication that your room has excess moisture that can have the potential for generating mold which could be dangerous to your health.

How do dehumidifiers work?

Which one you need depends on the size of the space you want to use it in, how many people are living in the home generating moisture through activities such as cooking, washing and doing laundry, and the extent of your damp problem. Choose the right capacity for the size of your space, the number of people living in it and the severity of your damp problem. If available, make use of timer or automatic shut-off features so the dehumidifier isn’t running continuously while you’re out of the house or asleep. A damp environment in our homes can be one of main contributor to ill health and COPD. Humidity can even damage furnishings like wallpaper, floorboards, and window seals.