Does a Dehumidifier Make Your Home Cooler or Hotter?

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Does a dehumidifier make your home cooler? It’s one of the most-searched questions during a UK heatwave — and the honest answer might surprise you. A dehumidifier does not lower the temperature like an air conditioner, but it can make a room feel significantly more comfortable by removing the sticky, heavy moisture that makes heat feel unbearable. Here’s what you actually need to know before you switch yours on.

The UK’s housing stock is built to retain heat, which means summer humidity can build up fast indoors. According to the Met Office, relative humidity above 60% significantly increases thermal discomfort — even at moderate temperatures. That’s where a dehumidifier earns its place.

How a Dehumidifier Affects Room Temperature

There are two main types of dehumidifier sold in the UK, and they behave quite differently when it comes to heat.

Refrigerant (Compressor) Dehumidifiers

Refrigerant dehumidifiers — like the Meaco MeacoDry Abc 12L, the Pro Breeze 12L, and the Meaco 20L Low Energy — work by drawing warm, moist air over cold coils. Moisture condenses and drips into the tank, and the now-drier air is released back into the room. The catch: that air is also very slightly warmer than it went in, because the compressor generates a small amount of heat as a by-product.

In a large, well-ventilated room you’ll barely notice it. In a small, sealed bedroom running for several hours, you may detect a 1–2°C rise on the thermometer. However, because relative humidity drops significantly, theperceived temperature — how hot it actually feels to your body — tends to go down. Your sweat can evaporate properly, which is how your body cools itself.

Desiccant Dehumidifiers

Desiccant dehumidifiers — such as the Meaco DD8L Junior — use a heated rotor to absorb moisture rather than cold coils. They are excellent at low temperatures, making them the right choice for garages, cellars, and conservatories in winter. But they do generate more heat during operation than refrigerant models, which makes them a poor choice for already-warm summer rooms.

If you’re in a heatwave and comfort is the priority, stick to a refrigerant model. Save your desiccant unit for autumn and winter.

Will a Dehumidifier Actually Make You Feel Cooler?

Yes — in most cases, and often noticeably so. The science behind this is straightforward: high humidity stops sweat from evaporating off your skin, trapping heat against your body. Even if the thermometer reads the same 28°C, air at 40% humidity feels far more tolerable than air at 75% humidity.

This is the same reason a 35°C day in southern Spain can feel bearable while a 27°C day in a muggy UK summer can leave you struggling to sleep. Temperature alone doesn’t tell the whole story — humidity is the hidden variable.

Running a refrigerant dehumidifier like the Meaco MeacoDry Abc 12L in a bedroom overnight and bringing relative humidity down from 70% to 50–55% can make a meaningful difference to sleep comfort, even if the air temperature itself rises fractionally.

How to Get the Most Comfort From Your Dehumidifier in Summer

A few practical tips that make a real difference:

• Set your target humidity to 50–55%. This is the sweet spot for summer comfort — dry enough to feel cooler, but not so dry that it becomes uncomfortable or static-prone.
• Use it alongside a fan. A dehumidifier removes moisture; a fan circulates the drier air. The combination is far more effective at cooling a room than either device alone.
• Don’t seal the room completely. A small amount of ventilation helps prevent the slight heat from the unit’s compressor building up in a very small space.
• Avoid using a desiccant model in summer. Models like the Meaco DD8L Junior are great in cold spaces but produce more heat — not what you want on a hot day.
• Empty the tank regularly. A full tank stops the unit working. During a heatwave the tank fills faster, so check it morning and evening — or use continuous drainage if your unit supports it.
• Right-size your unit. An undersized dehumidifier runs continuously and generates more cumulative heat without getting on top of the humidity. A Meaco 20L Low Energy is well-suited to larger open-plan spaces; the Meaco MeacoDry Abc 12L or Pro Breeze 12L for average-sized bedrooms and living rooms.

Refrigerant vs Desiccant in Summer: Quick Comparison

Feature	Refrigerant (e.g. Meaco Abc 12L)	Desiccant (e.g. Meaco DD8L Junior)
Cools the room?	No, but feels cooler	No
Heat output	Very slight (1–2°C)	Moderate — noticeably warmer
Best for summer use?	Yes ✓	No ✗
Best below 15°C?	No ✗	Yes ✓
Energy use	Lower	Higher
Noise	Low–moderate	Very quiet
Best UK pick	Meaco MeacoDry Abc 12L	Meaco DD8L Junior

Which Dehumidifier is Best During a UK Heatwave?

For most UK homes during a heatwave, these are the models worth considering:

Best for Bedrooms: Meaco MeacoDry Abc 12L

The Meaco MeacoDry Abc 12L is quiet, efficient, and well-matched to a standard UK bedroom or living room. Its low noise output makes it usable overnight without disturbing sleep, and Meaco’s 2-year warranty offers solid peace of mind. At 12L/day extraction capacity, it handles typical UK humidity levels without over-running.

Pros:

• Quiet enough for overnight use
• Compact and easy to move between rooms
• Energy-efficient for its class
• Carries Quiet Mark accreditation

Cons:

• Tank capacity requires emptying every 1–2 days in very humid conditions
• Not suitable for large open-plan spaces (see the 20L below)

Best for Larger Spaces: Meaco 20L Low Energy

If you’re dealing with an open-plan kitchen-diner or living room that retains heat badly during a heatwave, the Meaco 20L Low Energy offers considerably more extraction capacity while still operating efficiently. Its auto-humidistat means it only runs when needed, limiting unnecessary heat output.

Pros:

• 20L/day extraction — suits larger rooms
• Auto-humidistat reduces unnecessary run time
• Very energy-efficient for its size
• Continuous drain option so you don’t need to empty the tank

Cons:

• Bulkier than the 12L — less easy to move daily
• Slightly higher upfront cost

Best Budget Pick: Pro Breeze 12L

If you want a solid summer dehumidifier without spending a lot, the Pro Breeze 12L delivers dependable performance at a lower price point than the Meaco models. It lacks some of the refinements — it’s a little louder and less energy-efficient — but for occasional heatwave use it gets the job done.

Pros:

• Lower upfront cost than Meaco
• Straightforward controls — easy for beginners
• 12L/day suitable for most UK bedrooms

Cons:

• Slightly louder than Meaco alternatives
• Less energy-efficient over longer run times

What About the Mini Dehumidifiers?

Small plug-in models like the Pro Breeze 500ml Mini are designed for small enclosed spaces — wardrobes, caravans, bathrooms — not for making a room feel cooler during a heatwave. Their extraction capacity (often under 1L/day) isn’t sufficient to meaningfully reduce humidity in a room. Don’t rely on one of these as your main summer comfort solution.

Frequently Asked Questions

Does a dehumidifier cool a room like an air conditioner?

No. An air conditioner actively lowers the air temperature using refrigerant cycles and an outdoor heat exchanger. A dehumidifier only removes moisture — it doesn’t move heat outside. The room may feel cooler because lower humidity makes sweat evaporation more efficient, but the actual air temperature will not drop (and may rise fractionally).

Should I run my dehumidifier during a heatwave?

Yes — if your home feels humid and sticky, running a refrigerant dehumidifier is worth doing. Aim for 50–55% relative humidity. Combine it with a fan for best effect. Avoid running a desiccant model (such as the Meaco DD8L Junior) in summer if heat is already a problem.

Does a dehumidifier make a bedroom hotter at night?

Very slightly, in a technical sense — the compressor releases a small amount of heat. But in practice, the reduction in humidity usually more than compensates, making the room feel more comfortable to sleep in. A quiet refrigerant model like the Meaco MeacoDry Abc 12L is well-suited to overnight bedroom use.

What humidity level should I aim for in summer?

Between 40% and 55% is the ideal range for summer comfort. Below 40% can cause dry throats and static; above 60% starts to feel muggy and uncomfortable. A built-in humidistat on your dehumidifier will manage this automatically.

Can a dehumidifier replace a fan in a heatwave?

No — they do different jobs. A fan moves air around your body to accelerate sweat evaporation. A dehumidifier reduces the moisture in the air so that evaporation works more efficiently. Used together they are far more effective than either alone.

Is it safe to run a dehumidifier all day during a heatwave?

Yes, modern dehumidifiers with auto-humidistats are designed to run continuously when needed. Once the target humidity is reached, the compressor cycles off and the unit idles, using minimal energy. Just make sure the tank doesn’t overfill, or set up continuous drainage if your unit supports it.

The Verdict

Does a dehumidifier make your home cooler? Not technically — but it can make it feel considerably more bearable during a UK heatwave. By bringing humidity down to the 50–55% range, your body’s natural cooling system works properly again, which makes a real difference even when the thermometer says otherwise.

For most UK homes, the Meaco MeacoDry Abc 12L is the best all-round summer option — quiet, efficient, and compact. For larger spaces, step up to the Meaco 20L Low Energy. If budget is tight, the Pro Breeze 12L is a solid entry-level pick. Avoid desiccant models like the Meaco DD8L Junior during hot weather — save those for cold, unheated spaces in autumn and winter.

Related Reading

For more on managing indoor air quality and humidity in your home, see our guides to the best dehumidifiers for UK bedrooms, the best dehumidifiers under £100, and our full desiccant vs compressor dehumidifier comparison