What Size Dehumidifier Do You Need in the UK?

This guide uses current manufacturer performance tables, retailer specifications and Ofgem's electricity rate. We have not measured the sampled machines. Real extraction and consumption vary with temperature, relative humidity, fan setting, filter condition and how often the compressor cycles.

Read this with our guides to appliance running costs, total ownership cost and building a product shortlist.

Dehumidifier size chart for UK homes

This is a starting framework, not a guarantee. Currys lists a 12L Status model for rooms up to 30m², while Meaco describes its 12L low-energy class for one to two bedrooms and 20L for three to four. Door positions and airflow matter: one machine in a closed hallway cannot dehumidify bedrooms behind shut doors effectively.

Why “12 litres per day” rarely means 12 litres at home

Nominal extraction is normally measured under warm, very humid conditions. Meaco's detailed 12L table shows the point clearly: its model reaches 12L at 30°C and 80% relative humidity, but 4.92L at 20°C and 60% and only 1.62L at 10°C and 60%. The appliance has not failed; the air contains less accessible moisture and compressor efficiency changes.

The same manufacturer reports 5.23L per day for a 12L Arete One at 20°C/60% and 8.5L for its 20L model at the same condition. That is a more useful household comparison than the names. Look for a published extraction table at realistic temperature and humidity. If a retailer supplies only “up to”, seek the manual or manufacturer page.

Tank size is separate. Currys' Status 12L has a 2.1L tank: “12L” is extraction capacity, not the bucket. A small tank may need frequent emptying during initial drying, while continuous drainage can help only if a safe, downward hose route exists.

Current UK prices and specifications

Price snapshot: Currys and John Lewis UK pages checked 20 August 2026. Prices, stock, warranty and delivery change. Recheck the exact manufacturer code, local availability and basket at checkout; capacity labels are not controlled like-for-like performance results.

The £100 gap between sampled 12L models may buy lower consumption, quieter operation, a better humidistat, filter design or longer warranty—but those benefits require exact specifications. Do not assume a premium badge removes the need to compare watts, decibels, tank access and real-condition extraction.

Retailer service also belongs in the decision. Our Currys review covers delivery, collection and Price Promise checks, while the warranty guide explains the difference between retailer obligations and an added manufacturer promise.

How much does a dehumidifier cost to run?

Ofgem's average capped electricity unit rate for Direct Debit customers in England, Scotland and Wales is 26.11p/kWh from 1 July to 30 September 2026. Your tariff and region may differ. The calculation is:

Power in kW × hours × unit rate = energy cost. The standing charge is excluded because the household pays it whether or not this appliance runs.

These are maximum simple-time examples using listed power, not bill forecasts. A humidistat should switch the compressor off after the target is reached, so consumption may be lower. Conversely, laundry mode, a cold room or a persistent moisture source can keep it running longer. Measure actual use with a suitable energy monitor if cost matters.

A larger efficient machine can sometimes reach the target faster and then cycle, while an undersized one runs continuously. Wattage alone therefore cannot identify the cheapest solution. Compare litres extracted per kWh at realistic conditions where the manufacturer provides enough data.

Compressor or desiccant?

Compressor models

Compressor dehumidifiers are the common choice for heated homes. They generally use less electricity than desiccant models in moderate temperatures and work well for bedrooms, living rooms and laundry. Their extraction declines in cold spaces, and the compressor adds a distinct operating sound.

Desiccant models

Desiccant units pass air through an absorbent material and usually perform more consistently at lower temperatures. They can suit garages, boats, conservatories or unheated rooms, and their warmer exhaust may help laundry. The trade-off is commonly higher electrical input, so calculate cost from the exact wattage.

Do not use a domestic dehumidifier in a location the manual excludes. Minimum operating temperature, drainage, clearances and electrical safety matter. Water and damaged sockets are a dangerous combination.

Choose by the problem you need to solve

Window condensation

A 10–12L unit may help a heated small home, but persistent water can also indicate weak extraction, blocked vents, drying laundry or cold bridges. Wipe standing water and improve source control. A dehumidifier is not a substitute for repairing leaks or unsafe mould.

Laundry drying

Frequent indoor drying creates a concentrated load, making 12–20L and a directed laundry mode useful. Put the rack in a closed room with space around the appliance; do not aim hot air dangerously close to fabric or cover the outlet. A smaller room usually dries more efficiently than an open house.

Whole-home moisture

For several rooms, a 20L model and planned airflow are more credible. Keep internal doors open only where you want air to circulate and close outside windows while the machine is active. Move the unit between zones if the layout prevents central airflow.

After a leak

Stop and repair the source first. Significant flooding, contaminated water, wet structural materials or electrical risk calls for professional assessment. A small domestic machine may not dry hidden cavities and should not create false reassurance.

Humidistat, noise and tank design

A good humidistat is more valuable than an exaggerated maximum. Select a sensible target, commonly around 50–55% RH for routine control, and let the unit cycle. Avoid chasing extremely dry air: it wastes energy and may be uncomfortable. A separate hygrometer can check whether the built-in reading is plausible, but sensors in different positions will not match perfectly.

Noise figures need context. Currys lists 42dB for the Status model, while other units vary by fan speed. Decibels are logarithmic and test methods differ. In a bedroom, compressor cycling and tonal character can matter more than one number. Use a timer to dry the room before sleep if overnight sound is intrusive.

Check whether the tank lifts without spilling, can pass beneath a tap and is visible enough to monitor. Auto shut-off prevents overflow when correctly functioning. Continuous drainage needs a secure hose with continuous fall to a suitable drain; “continuous” does not mean the machine can pump uphill unless a pump is specified.

Filters and air-purifier claims

Some dehumidifiers include a dust or HEPA-type filter, but airflow and certification determine purification performance. A combined unit may reduce clutter; it is not automatically equivalent to a dedicated air purifier. Check replacement price, availability and whether the filter restricts airflow as it loads.

Clean the intake filter on the schedule in the manual. A blocked filter can reduce airflow, raise noise and impair performance. Our appliance repairability and spare-parts guide explains how low purchase prices become expensive when proprietary filters are scarce.

Placement and safe operation

1. Stand the unit upright on a stable, level floor with manufacturer clearances.
2. Close exterior windows while dehumidifying; manage internal doors for the chosen zone.
3. Keep intake and outlet clear of curtains, furniture and laundry.
4. Use the humidistat rather than continuous operation once initial moisture falls.
5. Empty and clean the tank, and maintain filters as instructed.
6. Do not use extension leads unless the manufacturer permits a correctly rated solution.
7. Investigate leaks, recurring mould or structural damp instead of masking them.

Our verdict

Our default recommendation is a good 12L compressor model for a heated one- or two-bedroom home and a 20L model for three to four bedrooms or regular indoor laundry. For an unheated space, compare desiccant performance and running cost instead of applying the same rule.

Compare the final shortlist in our UK shop directory, keeping the same extraction class, wattage, warranty and delivery route in every row.