Damp Maths compares products from the figures that brands and stores publish, then does the math. This page sets out where the data comes from, how products are picked, and what we do not do.
What we compare
47 products from 6 brands, read from 5 stores: B&Q, Ebac, EcoAir, Meaco, Pro Breeze, on November 14, 2026. The list is not exhaustive: it covers what these stores listed on that date, not the whole market.
Criteria
Our picks are not scores. Each pick is explained next to it, from these published figures:
- Type
- Extraction
- Power
- Noise
- Weight
- Tank
- Laundry mode
- Lowest working temp
- the price shown by the store, with the date it was read
Calculations
Our tools run in your browser from the figures above; results marked [calc] or [calculation] are our own arithmetic, and the assumptions are written on each tool page.
What we do not do
- We do not test products. We never write "tested" or describe a hands-on experience we did not have.
- No star ratings, no scores and no customer reviews written or imported by us.
- No discount percentage computed by us: a struck-through price only appears when the store shows it.
- No fake urgency or stock counters.
How we are paid
Some links may earn us a commission if you buy, at no extra cost to you. A commission may exist for the products we list; it is not part of the selection rules above. Details: Affiliate disclosure.
How often
Prices are not updated live: the date each price was read is shown next to it, and each page shows the date it was last updated.
Who writes
Pages are written and checked by the Damp Maths editorial team. Spotted an error? Tell us through the contact details on the disclosure page.
Where the numbers come from
Specifications were read on November 14, 2026 on each maker's own product page (Meaco, Pro Breeze, EcoAir, Ebac) and, for Princess and Russell Hobbs, on the B&Q listing, because neither brand's UK site could be read. Second prices come from B&Q (diy.com), matched by barcode or by exact model name. Argos, Currys, AO and John Lewis refused our automated reads that day, so their prices are not shown.
Litres a day are not comparable as printed
Meaco quotes extraction at 30°C and 80% relative humidity and also at 27°C or 20°C and 60%; EcoAir quotes its desiccant models at 20°C and 60%; Pro Breeze, Ebac, Princess and Russell Hobbs do not say which conditions their figure is measured at. We print each figure with its conditions, or say they are not published, and we never convert one into another.
Running costs
Cost per hour is the published power in watts, divided by 1,000, times the electricity unit rate of the Ofgem price cap for October 1 to December 31, 2026: 26.32 pence per kWh (Direct Debit, average for England, Scotland and Wales, read on ofgem.gov.uk on November 14, 2026). Standing charges are left out, since you pay them whatever you plug in. A dehumidifier's compressor stops when the room reaches the humidity you set, so the hours it really runs are yours to enter.