which dehumidifier to buy

Dehumidifier: when it helps, when it does not

Honest criteria for whether a compressor dehumidifier is the right tool. No ranking of untested models.

Updated 2026-09-01 · 11 min read

A dehumidifier is a machine that condenses vapour out of air and collects it. It does one job, and it only does that job well if that job is your problem.

When it makes sense

Hygrometer: persistent RH above ~60–65% in lived-in rooms.
Recurring condensation and indoor laundry.
Diagnosis pointing to indoor vapour, not rising damp.
A cellar with saturated air and walls that are not climbing from below.

When it is the wrong move

A wet band from the skirting up, salts, blowing plaster: structural track.
A stain after rain on a roof pitch or a sill.
Only the bathroom, ten minutes after a shower: extract at the source.
You have never measured: you are buying noise.

Estimate capacity in litres/day

Buying criteria (no top 10)

IgroCasa has no laboratory. We will not tell you “buy model X”. We will tell you what to read on the datasheet and where independent tests live. Consumer-test bodies publish lab results, usually behind a paywall: consult them, do not copy a ranking.

Litre capacity and test conditions (declared temperature and RH).
Airflow and a continuous-drain option if it must run for hours.
Noise: in a bedroom a low dB(A) figure beats “smart design”.
An adjustable humidistat. Without one the machine runs blind.
Refrigerant and filter care: hidden running costs.

Estimate electricity cost from your bill

FAQ

Compressor or desiccant?+

In a normally heated European living room, compressors are the common family. Desiccants hold extraction better in cold rooms (cellars). We do not publish a brand ranking.

Are the rated litres/day real in winter?+

They are often measured at 30 °C and 80% RH. In a 19 °C / 60% living room, output drops. Size with margin and read the test conditions.

What may help (after diagnosis)

No affiliate link is live. Products below are categories, not model reviews.

10–25 €

Digital hygrometer (probe if you can)

Without a relative-humidity number, every tip is guesswork. A €10–25 hygrometer is the first useful purchase — before any dehumidifier.

When: Always, as the first diagnostic step.

Not when: It does not replace a moisture meter or a rising-damp survey.

Affiliate link not connected — a category, not a model review.

80–350 €

Compressor dehumidifier

Useful if indoor air sits above ~60–65% and the cause is indoor vapour (showers, cooking, laundry), not a wall wet from below.

When: Measured high RH, window condensation, indoor drying, windowless bath.

Not when: Rising damp, leaks, stains that start at the skirting and climb.