Target Heat Drying for More Efficient and Effective Results
InClean Magazine - January/February 2015, Page 42. - By Garry Carroll*
Target heat drying is very different to setting up a few carpet fans and a dehumidifier. When most restorers are unnecessarily trying to dry the whole room, target heat drying is used to specifically target only the affected area. By adding heat, it is adding energy to the surface and it will dry a lot faster. By targeting the energy to only the areas that are wet, target heat drying is a lot more successful. It is similar to drying clothes in a tumble dryer. By adding heat to the small space and exhausting the wet air, the clothes will dry faster. With target heat drying, it is possible to dry a wall or a small floor area and still have the windows open. This is because you are only heating and drying the wet area and not the whole room.
When a restorer attends to dry a room, wall, concrete area, timber floor or a small area, they are all using the same drying methods but may not understand how to dry it using targeted heat drying. Generally, the restorer will set up a dehumidifier and some carpet fans to blow across the area. They will then return in a few days and hope that the wet area is dry. Many restorers are also not checking the structure or timber frame to see if it really is dry.
With gyprock wall and skirting, I will use a nail gun with stainless nails that will go through the skirting and into the frame. I place the pin probes onto the two stainless nails to get a reading on how wet the actual wall frame is. Centrifugal air movers are the worst fans to use for structural drying. The best fans for structural drying are axial fans because they push the air lower than a centrifugal air mover.
There are a lot of systems available for target heat drying. One of the systems that is very effective is DBK’s Drymatic Boost box with drying mats. A normal centrifugal air mover or a Dri-Eaz Velo low profile air mover is used to blow air through the heater (the boost box is a heater) and this pushes the hot air into the mat. In the back of the mat there are lots of little holes that have jets to blow the hot air through. The jets of hot air break the surface tension to release the moisture from the targeted area. Target drying systems are extremely effective in drying small areas of carpet with underlay on concrete, carpet with underlay on timber floors, one single wall or a small area of concrete or timber floor.
The mats come in many different sizes including 1 x 0.5m, 1 x 1m, 2 x 0.5m, 3 x 1m and 3 x 2m. All of these mats can also be joined together so if there is an area that is larger than the existing mat size it is possible to join a few mats to obtain the required size. Of a whole 64 sq m room there may be only 2 sq m of wet floor. A 2 x 1m mat with a fan and boost box can be placed directly onto the affected area. Instead of using one of the old systems of either blowing a fan across the floor or setting up a big Inject-i-dry system or having to dehumidify a whole room, the hot air can be blown onto and target only the damaged area.
It is the same with walls and skirting where water has run along the edge of the wall. There are mat setups that will blow the heated air along the areas and onto the wall so that it dries the whole area including wall, skirting, frame, subfloor, carpet, underlay and smooth edge. Target heat drying those areas is much more effective as it saves having to pull up the carpet, remove skirting or drying the whole room. It is a lot better to target dry an area than to demolish.
Target drying can also be done using dehumidification. A small area of floor can be dried by ducting hot air in under plastic. It is effective to duct from a dehumidifier through plastic into walls. A Dri-Eaz Turbo Minivent system can be used to duct the dehumidifier through the side of the fan and blow the air up into the ceiling through the down lights. This specifically targets drying of a ceiling instead of drying the whole area.
Recently I had to dry a set of stairs that consisted of wool carpet, felt underlay and timber subfloor. The old way of drying it would involve hours of wrapping it in plastic to contain the area, adding a dehumidifier to dry it and blowing a fan up underneath. Possibly the stair treads may have even had to have been pulled off. Now some heat mats can be run along each section and hot air is blown from the fan and through the boost box. It is a lot simpler to dry the stairs using target heat drying methods.
The benefits of the target drying systems are that they are quiet and use gentle heat, they are easy to set up and it is a lot more value for the insurance companies and insurance builders, and the commercial and residential clients.
Technicians looking to target dry should be thinking about how they can generate some heat directly onto the wet area, with any of he methods mentioned above. Whether it is with the Drymatic drying mats, using plastic, by making the area smaller or by another means, it is always more effective to to use target heat drying.
* Garry Carroll is the managing director of Drymatic Heat Drying Australia, and director of All Aces Services ( www.allaces.com.au )