There's nothing more frustrating than settling in on a winter evening, heating on, only to realise the room still feels decidedly cold. And if you've recently started running a dehumidifier to keep condensation at bay, it's easy to point the finger at that.
The best dehumidifiers are built to pull moisture out of the air rather than warm your home, but that doesn't mean they're cooling it down either. In fact, the experts we spoke to say most models give off a little heat as they run. So why might you still be reaching for a jumper?
More often than not, it comes down to where your dehumidifier is placed, how it's set up and which type you own. We asked air quality and ventilation experts to explain what's really going on and how to stay warm while your dehumidifier gets on with the job.
Can a dehumidifier make your home feel colder?
It’s an easy assumption to make. Many dehumidifiers – particularly compressor models – have a cold coil inside, so surely they’re cooling the air? But the experts are clear that in most cases, the room’s temperature isn’t actually dropping.
So why might a room feel colder when it isn’t? Jack Duffy, small appliance expert at AO, says the answer often lies in the air itself:
“Dehumidifiers don’t cool the air in the same way an air conditioner does. What often changes is how the room feels. Once excess moisture is removed, the air can feel fresher and less heavy, which some people can interpret as being cooler.”
Scott Byrom, energy and appliance expert at The Energy Shop, points to a second culprit: the fan.
“A domestic dehumidifier generally adds a little warmth to the room rather than cooling it,” he says. “The moving air from the fan may feel draughty if it blows directly towards you, but that doesn’t mean the appliance is lowering the room temperature. If this feels uncomfortable, adjust its position while keeping the vents clear.”
In other words, a dehumidifier is far more likely to change how a room feels than its actual temperature. But if your home seems colder with it running, it’s worth looking at how it’s being used.
5 things to check if your room feels colder
If your room feels colder with the dehumidifier on, the experts agree the machine itself is rarely to blame. As Jack Duffy puts it: "If a room genuinely feels colder, it's more likely to be linked to how the appliance is being used, such as running it alongside open windows or using it in an unheated space."
These are the most common cold-related dehumidifier mistakes to rule out first:
1. The unit is sitting next to your thermostat
Where you put a dehumidifier is more important than you might think, and next to the thermostat is one of the worst spots.
“Dehumidifiers tend to release warm air, so don’t put it next to the thermostat as it can interfere with the temperature reading and your heating might switch off before the room actually reaches the right temperature,” says Rhys Powell, director of operations at WarmZilla. In other words, your thermostat thinks the job’s done, the boiler clicks off, and the rest of the room – or the rest of the house – is left colder than you’d like.
It’s also worth keeping your dehumidifier well away from the boiler itself, though for a different reason. “You don’t want it to block ventilation and it’s best to avoid exposing it to excessive heat, so definitely don’t put it next to your boiler,” says Rhys.
2. You're running a compressor model in a cold room
Compressor dehumidifiers work by passing air over a cold coil, and they struggle when the room itself is chilly. That's not the machine cooling the room, it's the room itself hampering the machine.
"If that is the case, I'd check the temperature at which your machine is designed to operate, because a compressor model can struggle to extract moisture properly in a cold room. In that situation, the problem is the room temperature affecting the machine's performance, not the machine making the room colder," says Rhys Powell.
Chris Michaels, founder of Meaco, puts some numbers on it: "Smaller compressor models, 12L or lower, generally become less effective below about 15°C, although larger 20L and 25L models can work well down to around 10°C. As temperatures fall, ice can form on the cooling coils, so the machine spends more time defrosting and less time collecting water."
Scott Byrom has shaped the UK energy market since 2006, when he helped launch energy switching at MoneySupermarket.com. He pitched QR codes on energy bills at Number 10 and regularly comments on energy for national newspapers, Sky News, BBC News and GB News.
Rhys oversees the day-to-day running of WarmZilla, bridging the gap between management and the technical teams. With eight years of experience as a Gas Engineer and additional F-Gas qualifications, he serves as the company's resident expert on both traditional heating and modern air conditioning systems.
Chris and his partner Michelle started Meaco in 1991. Meaco is now regarded internationally as a major player in the dehumidifier industry selling to 20+ countries throughout Europe, North America and South Africa. Meaco sets the benchmark for quality and development in its sector, leading by example and reducing the energy consumption of its appliances.
3. The humidity is set too low or there's no humidistat
If your dehumidifier keeps running long after the air is dry enough, you'll be sitting in a steady breeze for no good reason.
"Aim for 55% relative humidity and use a model with a humidistat so it stops drying once that level is reached," says Chris Michael. "Without a humidistat, the machine may continue running unnecessarily, and the moving air can make you feel colder through its wind-chill effect, even though it is not lowering the room temperature."
4. The windows are open
Running a dehumidifier with the window open lets cold air in, while the machine battles an endless supply of damp air from outside, so you end up with a chillier room and a dehumidifier that’s working harder than it needs to.
“Keep external windows and doors closed while it’s running so you’re treating a defined space,” says Scott Byrom.
That doesn’t mean you should stop airing your home altogether. Scott still recommends ventilating your home regularly and using extractor fans when cooking or showering – just not while the dehumidifier is on.
5. You've turned the heating up to compensate
It's tempting to crank up the thermostat to win back that cosy feeling, but Noel Fok, CEO and co-founder of EcoAir, warns this can backfire when it comes to moisture.
"It's a common misconception that turning the heating up will reduce humidity,” he says. “However, warm air carries more moisture, and humid air in a warm interior creates the perfect environment for microbes to thrive, and will also cause condensation issues as the warm air settles and condenses on colder surfaces, such as windows or walls."
Shop our top picks for tackling cold and humidity
If you're unsure which type of dehumidifier you need, these budget-friendly thermometers will monitor your room's temperature and humidity levels, so you can make an informed decision.
This compressor dehumidifier effectively reduces moisture in warmer rooms and is capable of removing up to 12 litres of water per day.
With an anti-bacterial filter and a lightweight design this desiccant model is highly-rated by the Homebuilding team.
Noel Fok is CEO and co‑founder of EcoAir, established in 2006. Based in London, he leads the company in creating innovative, eco‑friendly air treatment and cooling solutions.
How to use a dehumidifier in winter without feeling the chill
Most of the problems above are easy to avoid once you know what to look for. Beyond steering clear of the thermostat and keeping windows shut, these expert tips will help your dehumidifier and heating work together over the colder months.
1. Keep the heating steady
There's no need to choose between your heating and your dehumidifier – in fact, they work best together. Rhys Powell recommends keeping the room at a comfortable ambient temperature rather than letting it swing between hot and cold.
"Run the dehumidifier in the room where moisture is building up, and keep the heating at a comfortable and steady temperature," he says. "A compressor model will generally extract moisture more effectively in a warmer room so it's best to keep the space heated (but you don't need to turn the thermostat all the way up for it to work!)."
2. Let the automatic controls do the work
A dehumidifier that keeps running once the air is dry enough creates a breeze that can make you feel colder. So rather than guessing how long to run your dehumidifier for, let it decide for itself. Automatic controls do exactly that, and Jack Duffy says they’re worth prioritising if you’re buying a model for winter.
“If you’re buying a dehumidifier specifically for winter, I’d look beyond just the extraction rate. Features such as a built-in humidistat and automatic humidity control can make a big difference to both performance and running costs.”
3. Keep it somewhere warm – but not against a radiator
Because compressor models perform better in warmer air, a heated room is the right place for one. Just don’t push it right up against the radiator, or so close that the heat is blowing straight into the machine.
“A dehumidifier needs to draw in room air and circulate it properly so if it’s too close to heat it won’t work as well,” says Rhys Powell. Direct heat can also affect the conditions around the machine’s humidity sensor.
4. Close doors to hold in the warmth
If you're treating one room, shutting the door keeps the heat from your radiators where you want it. It also helps the machine work faster. Rhys Powell explains: "Keep the door closed if you're trying to reduce humidity in one particular room so that the dehumidifier can concentrate on that space instead of drawing in air from the rest of the house which may contain more moisture. It's especially useful when drying washing or tackling condensation in a bedroom."
FAQs
Can a dehumidifier make your home feel warmer?
A little. Every dehumidifier gives off some heat as it runs, but desiccant models give off far more. According to Chris Michael, a compressor model typically pushes out air around 1–2°C above room temperature, while air from a desiccant model is around 10–12°C warmer, which is one reason they’re often seen as the best dehumidifiers for cold rooms. Just don’t mistake it for a heating system. Chris points out that once the machine switches off, the room will gradually lose that extra warmth.
There’s a longer-term benefit to dehumidifier's too. In a damp home, moisture soaks into walls, soft furnishings and fabrics, which can leave a room feeling cold and clammy, however high the heating is set. Reducing humidity tackles that. “Reducing humidity can make a home feel more comfortable in winter because dry air is often easier and more efficient to heat,” says Jack Duffy.
Does a dehumidifier make your home cheaper to heat?
There’s no firm evidence that it does, though some of our experts are more optimistic than others. Noel is the most positive: “Dehumidifiers stand out as an answer to rising energy costs,” he says, arguing that because moisture-laden air is harder to heat, lower humidity allows for significantly cheaper heating in winter. He also estimates that using a dehumidifier’s laundry mode instead of a tumble dryer could save between £50 and £250 a year, based on three loads a week.
Chris Michael is more cautious. While he agrees a drier home is easier to keep comfortable, he adds that “improved comfort does not establish a net saving on bills”.
None of our experts shared data to show that a dehumidifier lowers heating bills overall. And remember, the dehumidifier itself uses electricity – particularly desiccant models – so any saving on heating would need to outweigh that. Our guide to dehumidifier running costs explains more.
What about drying laundry – does it make a room warmer or colder?
Slightly warmer. “A dehumidifier releases warmer air as it removes moisture from the washing, adding warmth to the room,” explains Chris Michael. “Keeping the door closed helps retain this warmth, which may become more noticeable as the machine runs, particularly with a desiccant model.”
For the best results, Rhys Powerll recommends drying your clothes in the same room as the dehumidifier, rather than in another part of the house. That way, the moisture from your washing is drawn straight into the machine instead of spreading to other rooms, where it could end up as condensation on cold windows and walls.
Still struggling with a chilly spare room or home office? Our pick of the best portable heaters offers a quick, targeted boost without cranking up the central heating for the whole house.
