In a wet property, heat alone without a dehumidifier would be bad news. Higher temperatures would give greater potential for mould development and deterioration of building materials.

However once the dehumidifiers are in situ, the affect of heat is beneficial because it increases the rate of evaporation. As a guide, we indicate that the evaporative rate approximately doubles with an increase in air temperature from 20 to 30 degrees celsius, with a further doubling of the evaporation rate with an increase to 40 degrees celsius.

Dehumidifiers and fans themselves will generate heat, particularly in a compact space, but adding heat, especially in unheated properties, is worth considering.

• What fan do I need?
• What type of heater do I need?