Dehumidifier Size Guide: Litres per Day Explained
By Home & Kitchen Appliances – Morphy Richards UK | Published: 2026-10-19
Category: Buying Guides
Understand dehumidifier litres per day, match the right capacity to your room size, and avoid over- or under-sizing for effective moisture removal.
Quick answer
Choose a dehumidifier that removes roughly 10–12 litres per day for small damp rooms, 20 litres for medium spaces, and 30 litres for large or very humid areas.
Why litres per day matters
The litres per day rating tells you how much moisture the unit can pull from the air in 24 hours. It is the most direct measure of dehumidifying power, so it should be your first check when comparing models.
A unit that is too small will run constantly and still leave the air feeling clammy. One that is too large may cycle on and off frequently, which can waste energy and reduce effectiveness in smaller spaces.
How room size and dampness change the number
Manufacturers usually rate dehumidifiers for a maximum room area, like 24m², 40m², or 60m². That figure assumes average moisture levels. In a humid climate or in rooms with persistent damp problems, you may need a higher litres-per-day capacity than the room size alone suggests.
For example, a 12-litre unit might suit a 24m² bedroom in normal conditions, but if that room has a leak, poor ventilation, or you dry laundry indoors, a 20-litre model would give you more headroom.
Frequently asked questions
- How many litres per day do I need for a small bedroom?
- For a room up to about 24m² with normal moisture, a 12-litre model is usually enough. If the room feels damp often, step up to 20 litres.
- What size dehumidifier do I need for a living room?
- A living room around 40m² typically calls for a 20-litre unit. For larger open-plan areas up to 60m², choose a 30-litre model. Measure the room length and width to confirm the square metres before you buy.
- Does a humid climate change the litres per day I need?
- Yes. In humid climates or during wet seasons, moisture loads are higher. Pick the next size up from what the room area suggests, or choose a model with a higher litres-per-day rating. If you already own a dehumidifier and it runs non-stop without reducing humidity, it is probably undersized.
Dehumidifiers that match these sizes
- PureFresh 12 Litre Dehumidifier with Air Purifier Function - White: The PureFresh 12 Litre Dehumidifier is suited for rooms up to 24m², such as master bedrooms and living spaces. This is a sensible starting point for a small bedroom or study with moderate dampness.
PureFresh 12 Litre Dehumidifier with Air Purifier Function - White - PureFresh 20 Litre Dehumidifier with Air Purifier Function - White: The PureFresh 20 Litre Dehumidifier is suited for rooms up to 40m². Choose this size for open-plan living areas or if you need faster moisture removal in a medium-sized home.
PureFresh 20 Litre Dehumidifier with Air Purifier Function - White - PureFresh 30 Litre Dehumidifier with Air Purifier Function: The PureFresh 30 Litre Dehumidifier is suited for rooms up to 60m² and includes an oscillating function that swings airflow between 45° and 90°. This capacity handles large or very humid spaces, and the oscillation helps distribute dry air more evenly.
