Water is the universal solvent in the cleaning industry; it’s a vital ingredient in all of our businesses and can be a real benefit when used correctly. However, it can also cause problems. If, for example, organic materials found in carpet, underlay, plasterboard and wood remain damp for extended periods, they can deteriorate and affect the quality of the indoor environment. To quantify that, moisture levels at or above 75% for extended periods can lead to problems, the most common of which is mould growth.

We see mould growth around us in everyday life, often in shower cubicles, basements, caravans and other places with high levels of relative humidity and little air movement over periods of time. So, to avoid moisture related problems, we should control the indoor environment and keep relative humidity low enough to avoid condensation forming.

Relative Humidity (RH) is the amount of water that’s held in the air at a particular temperature. A comfortable reading in an office or home environment would be 30% RH and 20 Degrees C.

When we know the humidity level it can help us to decide whether we need to use equipment for drying or, perhaps just open the windows. This is important in routine cleaning as well as when we are involved in flood restoration.


If we measure the humidity and take action to reduce it, we then need to measure again to monitor our progress. This requires the right tool for the job. Of course professional restorers need to spend heavily for a high tech tool like a Protometer whereas professional carpet and upholstery cleaners could visit Maplins who can supply a Thermo Hygrometer for as little as £20. As part of wet cleaning, we begin drying with suction through a wand or upholstery tool. While this takes the water away to a waste tank for storage, we can supplement the drying process with THE most important factor, air movement, which encourages evaporation. Of course that air movement needs to be across the wet surface, not just blowing and buffeting around the middle of the room. We should try to create a vortex or a whirlpool of moving air to maximise evaporation and, at Chemspec, we have a range of air movers designed for this purpose. When cleaning distinct areas it is simple to clean the first room, set up the dryer and move to the next room. This way drying takes place as you work and the last area is drying as you reload the van at the end of the job.

Drying occurs in either an ‘Open’ or a ‘Closed’ system. An open system is created by opening the outside doors and windows to allow the outside environment to absorb the airborne moisture. This only works if the RH of the outside air is lower than it is inside a wet room otherwise we need to use a closed system, for example, if it is raining. A closed system requires a de- humidifier and, as Chemspec is part of the same group of companies as Dri-Eaz, we offer their equipment and share their industry leading training, research and drying data. By using a dehumidifier such as the Dri- Eaz Revolution you will generate plenty of heat as well as removing moisture. Temperature is an important factor as a 10 degree increase in temperature doubles the evaporation rate. Similarly, increase air movement by 4 and you will double evaporation. So, consider the massive impact that you can have on drying times when you maximise the effect of both air movement and temperature.