Humidifiers function by adding moisture to the air to prevent dryness that can cause irritation in many parts of the body.

That doesn’t mean capacity should be ignored though. As a general rule, bigger capacity dehumidifiers can deal with larger spaces and higher levels of moisture. At 15kg, the Midea is a bit of a challenge to get upstairs. That’s a real shame, because this powerful unit is perfect for bedrooms. It has a built-in ioniser which helps to purify the air and a smart setting which senses and automatically controls the humidity of a room, keeping it between 45 and 55 per cent to reduce any bacteria growth which can lead to mould.Domestic dehumidifiers can extract up to 25 litres of water per day. We have largely focused on 20l models since these are the most popular for domestic use. For larger spaces, damper environments or colder temperatures, choose something more powerful. (Or vice versa for smaller spaces.)

However, if you're able to extend your budget a little then it’s well worth looking at the Meaco Arete One Dehumidifier. This is more of an ivestment, but is our top-rated dehumidifier overall. Plus, it's quiet, easy to use, works superbly and is very energy-efficient compared to other compressor models. Its Smart Laundry Mode also makes it one of the best dehumidifiers for drying washing indoors. There are 10, 12, 20 and 25L models available, and, all offer a built-in air purifier that means they improve indoor air quality in more ways than one. You can get the full details in our MeacoDry Arete One Dehumidifier review. How we tested The level of moisture in the environment. This is a more subjective measure, unless you use a humidity monitor. But you should have an idea of how damp a space is by noticing where moisture is accumulating.Despite its compact size, this dehumidifier effectively removes moisture in the air within a 15-square-metre space—the model measure 5.1D x 15.6W x 21.8H centimetres. What you need to remember here is that size really does matter. This is a small and compact dehumidifier suitable for small rooms, so it will struggle to be effective and get overwhelmed when placed in a large area. It has a 250 ml per day extraction capacity, so you can leave it running for a couple of days before it reaches its 500-millilitre capacity. A dehumidifier's extraction rate is an average of how much moisture it can remove from the air during a given timeframe. Most commonly this is measured in litres per day, so an extraction rate of 10L/per day means the dehumidifier should be able to extract 10 litres of moisture within 24 hours if running continuously. In practice, this also depends on the humidity levels of the room, and the ambient temperature. The Pro Breeze is great if you’ve got a smaller space and you want something that doesn’t cost a lot to run,” says expert Kandola. “It’s probably about a penny an hour.”