Dehumidifier
Not a cleaning tool at all, and the most effective single purchase against mould — because it treats the cause the spray bottle cannot reach.
In detail
A dehumidifier removes water vapour from indoor air, either by condensing it on a cold coil or by adsorbing it onto a desiccant wheel. It appears in a cleaning catalogue because the authorities on mould are unanimous that the moisture problem is the problem: the US environmental regulator's guidance states that unless the moisture source is corrected, growth returns, and a state health department's guidance frames control of indoor humidity as the primary measure rather than a supporting one. Every mould spray in every bathroom removes a symptom that will return on the same timetable it returned on last time. Lowering the relative humidity, ventilating after showering and cooking, and drying wet surfaces changes the timetable itself. A dehumidifier is also the reason a wetted carpet or a washed upholstery panel dries in hours rather than a day, and drying speed is what decides whether a cleaned soft surface develops an odour or brown wicking marks afterwards. It is not a substitute for fixing a leak, a cold bridge or a failed damp course, and it should not be treated as one.
What works
Dehumidifier is effective against Mould Supported
Sources for this page
Sources
A Brief Guide to Mold, Moisture, and Your Home
United States Environmental Protection Agency (EPA), Office of Air and Radiation, 2012 · Government or regulator
Relied on for: That controlling indoor moisture is the primary measure against mould growth and that mould returns where the moisture source is not corrected. (states this directly)
Verification: a person has read the passage relied on.
Read on — Read in full. The load-bearing passages are 'Cleanup and Biocides' (p.15), the 'Please note' immediately below it, 'Mold Cleanup Guidelines' and the Bathroom Tip (p.6), the porous-materials bullet (p.7), 'How do I get rid of mold?' (p.3), 'What to Wear' (pp.8–9) and the humidity targets (p.11). Supports a wider statement — our claim was widened. The catalogue previously recorded that no authority it held recommended bleach for mould. It can now record that the federal regulator positively does not recommend it as routine, while carrying that this is advice against ROUTINE use rather than a prohibition, and that the agency leaves room for professional judgement. The kill-versus-remove sentence became the governing fact of the whole mould family and is what several backlog rows actually needed. The Sprint 5 record against the short EPA page stands unchanged and correct about that page; this is a different document, cited separately.
Minnesota Department of Health · Government or regulator
Relied on for: That controlling indoor humidity and drying wet materials promptly are the measures that prevent mould growth. (states this directly)
Verification: a person has read the passage relied on.
Read on — The cleanup steps, the bleach step, and the salvageable-materials section. Page last updated 19 February 2026. Supports the claim as stated.
Last reviewed by a person on .