5 Steps to Buying the Best Dehumidifier for Your Home

The first sign of damp is often a dark bloom behind the loo or that musty smell that refuses to leave. So you decide to set on buy a dehumidifier, until your faced with litres per day, compressors vs desiccants, tank capacities, and running costs…A wall of jargon between you and a dry, fresh home.

Take a breath. This guide to buying the best dehumidifier cuts through the noise. By the end, you’ll know which dehumidifier you need, how big it should be, and how to use it so damp doesn’t get the upper hand.

1) Do You Need a Dehumidifier?

Unfortunately, most UK homes have damp to contend with – we just get used to it. Everyday things like cold weather, steamy showers, and wet washing hanging over radiators cause the air to grow heavy with moisture. Suddenly, your house feels colder than it should, even with the boiler working overtime.

Here are some tell-tale signs of excess moisture in your home:

Condensation beading on windows
Musty, slightly sour smells
Black mould or speckled mildew
Peeling wallpaper
Swollen or rotting wood
Triggered asthma/allergies

If you’re nodding along, don’t worry – a dehumidifier can help. But before you add one to your basket, be sure to rule out any leaks, because no machine can remedy a broken roof tile or cracked pipe. If water is getting in – not just lingering in the air – a dehumidifier won’t address the root cause.

To identify a leak:

Run your hand the damp area
Use a cheap damp meter
Trace stains back to their source

If it is a leak, speak to a plumber or your water provider immediately – it’ll save you a lot of hassle down the line. If not, you’re dealing with humidity. But now you have a fighting chance.

Before you buy a dehumidifier, try:

Opening windows after showers
Use lids when boiling
Dry laundry outdoors when possible
Check hoses on washing machines/dryers
Clean rugs (they hold moisture)
Seal obvious cracks

If you try these fixes and the air still feels heavy, a dehumidifier is essential.

Black mould starts to flourish around ~50% humidity. But if you keep the humidity level below that, you’ll prevent it from forming. Read our expert blog for a detailed breakdown:

How to Get Rid of Damp

2) How Dehumidifiers Work (and Why Types Matter)

All dehumidifiers do the same job: they pull moisture from the air, collect it, and return it drier. But it’s how they do this that matters, because it determines:

Where dehumidifiers work best
How much water they can remove
How much energy they use

Let’s look at the three main types of dehumidifiers, starting with the most common, the compressor.

Compressor Dehumidifiers (Refrigerant)

The dependable all-rounder.

Compressor dehumidifiers work like a fridge: moist air passes over cold coils, the water condenses and drips into the tank before it’s heated and dispersed as warm air.

Compressors are best suited in heated homes (≈15–30°C) where conditions are stable, making them a solid choice for most UK homes.

Why people choose them

Strong extraction (≈10–25L/day)
Great for laundry drying
Efficient at normal room temperatures

Best for

Everyday damp in bedrooms, living rooms & home offices

Browse Compressor Dehumidifiers →

Desiccant Dehumidifiers

Desiccant dumidifier in modern living room

The cold-weather specialist.

Instead of cold coils, desiccant dehumidifiers use moisture-absorbing material on a rotating wheel. This makes them effective in spaces where compressors slow down. They’re often lighter and quieter than compressors, too.

Why people choose them

Excellent in cold rooms
Reliable when the heating isn’t on
Good for remote spaces

Best for

Garages, conservatories, lofts, utility rooms

Browse Desiccant Dehumidifiers →

Peltier Dehumidifiers (Thermo-Electric)

The lightweight problem-solver.

Peltier dehumidifiers work by passing air over a tiny heat sink, before condensing moisture into the tank. These are quiet and compact, but extraction is negligible.

Why people choose them

Whisper-quiet
Low running cost
Very compact

Best for

Cupboards, caravans, small bedrooms with light condensation

Which is the best dehumidifier for you?

Dehumidifier Type	Best for	Work Best At
Compressor	Most homes	15–30°C
Desiccant	Cold rooms	1–15°C
Peltier	Small spaces	15°C+

3) What Size Dehumidifier Do You Need?

When it comes to dehumidifiers, size doesn’t refer to height or footprint – it’s the extraction capacity: how much water the unit can pull from the air in 24 hours. Typical UK dehumidifiers range from 250ml → ~20L/day.

Selecting the correct dehumidifier capacity is essential because you’ll solve your damp issue quickly while keeping electricity costs down.

How to Choose the Right Capacity Dehumidifier

Three things determine what you need:

Room size
How damp the space is
Temperature

Rules of thumb

Small room / light damp → 0.5–1.5L/day
Most UK homes → 10–12L/day
Heavy damp / drying laundry → 16–20L/day

If the space is cold (e.g., spare room, garage), desiccant dehumidifiers often outperform compressors with a higher capacity. To save hassle down the line, you can pick up a cheap hygrometer to identify your room’s humidity level.

When to size up

Go for 20L+ dehumidifier, like the Vonhaus 30L Dehumidifier with Laundry Mode, if:

You’re drying laundry regularly
Condensation returns daily
Rooms smell musty
You see wall/ceiling moisture
Timber is warping

Quick Dehumidifier Size Guide

Damp Level	Small Room	Medium Room	Large Room
Mild	0.25–1L	1–10L	10–12L
Moderate	0.25–0.5L	8–12L	12–16L
Severe	5L	12–14L	18–20L
Drenched	7L	14–16L	20–25L

3) Dehumidifier Water Tank Size – Does It Matter?

The short answer is yes, but nowhere near as much as extraction capacity. A dehumidifier’s tank simply holds the moisture it pulls from the air. And most tanks are smaller than the unit’s daily extraction rating. For example, a 20L/day dehumidifier will not have a 20L tank, more like 3-4L. So, the why mismatch? Because once a room reaches healthy humidity, the dehumidifier cycles on and off, so the tank rarely fills to capacity each day.

What matters is:

How often you’re home to empty it
How damp the room is to begin with

As a rule of thumb, if you’re running your dehumidifier occasionally, a standard tank (12-20L) will suffice. So, you'll be safe with the following options:

But if the damp is severe or you’re leaving your dehumidifier on while you’re out, you'll be best off with our 30L Smart Dehumidifier with Laundry Mode.

5) Setting Up and Maintaining Your Dehumidifier

Dehumidifiers aren’t quite set-and-forget appliances, but they’re close. Here’s how to set yours up, use it properly, and maintain it so it keeps your home fresh and damp-free for years come.

First Time Dehumidifier Setup

On first use, your dehumidifier is clearing a backlog of moisture. Give it time – anywhere from 8–24 hours, depending on how damp the space is. Once the room settles to a healthy 40–50% humidity, most homes only need the unit 2–4 hours a day to maintain balance.

If you’re using a compressor dehumidifier, let it stand upright for an hour before switching on, so the refrigerant settles.

Where to Place Your Dehumidifier

Follow these simple placement tips to get the most out of your dehumidifier:

Close windows & doors
Position centrally for whole-room drying
Leave 15cm+ clearance all around

Target problem areas by placing it nearer to wet walls, fogged windows or damp cupboards

Plug directly into the mains (avoid extension leads)

Dehumidifier Modes & Settings

Auto mode

Set your target humidity (≈45%) → the unit cycles only when needed
Smart, simple & energy-efficient

Laundry mode

High airflow to dry clothes quickly and cheaply
Check out our Dehumidifiers with Laundry Mode

Continuous drainage

The no-admin option for daily use

Target humidity:

40–50% most of the year
30–40% winter

Remember, above 50% is where mould thrives.

Dehumidifier Maintenance

Nothing complicated here, just a few spot checks to keep your dehumidifier running smoothly.

All Dehumidifiers

Power off before cleaning
Empty the tank regularly
Wash the tank every 2–3 weeks to prevent mould

Compressors

Dust coils occasionally
Coils icing up? The room is too cold → raise the unit or warm the space

Desiccants

Clean the filter every 2–3 weeks

Peltiers

Brush dust from vents
Clean filters = stronger airflow, better extraction, and lower running costs.

The Vonhaus Free 2-Year Warranty

Your dehumidifier should last years – and we back that promise. Every Vonhaus dehumidifier includes:

And if something goes wrong within the warranty period, we’ll repair or replace your dehumidifier. You handle the humidity; we’ll handle the peace of mind.

Conclusion – Your Next Step

You’ve now got the essentials to choose the best dehumidifier for your home. Let’s recap:

Confirm the damp in your home is humidity, not a leak
Choose the best dehumidifier for your needs:
→ Compressor dehumididier for heated homes
→ Desiccant dehumidifier for cold spaces
→ Peltier for small, light jobs
Match the unit's tank capacity to room size & damp severity
Use smart placement & auto mode
Keep it clean

And that's it! Follow these simple tips, and you're sure to choose the best dehumidifier for your home. But if you're still not sure after browsing our dehumidifier range, narrow your list down to these three: