Dehumidifiers

In my single skin brick Garage/Workshop the relative humidity (RH) is about 80% most of the time in autumn/winter (Berkshire UK). The bricks seem to act like sponges that absorb water and slowly release it, even on dry days, increasing the humidity levels.

In such an ocasion the dehumidifier should work 24/7 on it’s highest setting, and I am not sure that it will manage to decrease the RH effectively, adding, according to the specifications in your link, £878 to the annual electricity bill.

Maybe you will be better off if you add some sort of insulation first and then consider the use of a dehumidifier or heating for your workshop.

Hej Mark,

My 56 sqm combined loft and workshop is kept at around 43% relative humidity thanks to a Wood’s DS40FS dehumidifier. This particular model might be a bit difficult to find in GB, but there are other models and, supposedly, brands with the same characteristics.

1. Good fan that really circulates the air in the room. In a non-insulated room or a loft (roof heat generates a humidity gradient) the humidity is not evenly distributed, which makes air-circulation beneficial.

2. Sufficient capacity. An undersized dehumidifier will consume a lot of electricity without perhaps reaching the desired relative humidity.

3. Continous water drainage, and not into a tank that has to be emptied.

4. Big enough filters that are easy to replace (and not to expensive). At least my workshop can be become dusty, despite being hand tools only.

Insulation and heating will of course not only make for a more pleasant workshop, but also – which goes without saying – prevent condensation, as long the indoor temperature is above the dew point. A dehumidifier allows for drops in temperature (like day and night) without condensation. As room a reasonable room temperature makes working much more comfortable, and a controlled humidity prevents both tools corroding and wood warping, I’ve gone for both.