How much airflow you need
Airflow is quoted in cubic metres an hour (m³/h), or in cubic feet per minute (CFM), which you multiply by about 1.7 to compare. As a rough guide, compact units of a few hundred m³/h suit stairs and tight corners, snail and floor dryers of around 1,000 to 3,000 m³/h a wet floor, carpet or wall, and fans of 3,000 m³/h and more a hall or site.
Snail, low profile or axial
A snail dryer squeezes air through a narrow slot into a fast, flat jet that skims across a floor or up a wall, drying carpet, skirting and plaster. Low profile models do the same from a slimmer body that sends air under furniture. An axial fan throws a big volume of air across a wide area for halls and sites, and many take a duct to blow fresh air in or pull dust and fumes out.
Dehumidifier, power and noise
Air movers speed up evaporation, so run a dehumidifier alongside or ventilate the space, or the moisture simply moves into the air and soaks into other materials. Most draw between 100 and 1,000 watts, models with built-in sockets can be chained from one outlet up to the maker's limit, and 110 volt versions suit building sites. The bigger ones are loud, so keep them out of occupied rooms where possible, and clear dust and fluff from the intake grille.
