Airflow in Water Damage Restoration



Airflow is an absolute necessity, when doing water damage restoration. The amount of air movement, needed, can vary depending on the size and needs of the job.

There are many uses for it:


1 On a large job, requiring lots of evaporation, moving air carries warm air to the cooling, evaporating, surfaces, replacing the heat removed by escaping vapor molecules.

Heat energy is required for evaporation. Antarctica is one of the driest places on earth due to a lack of evaporation. For every twenty degree increase, of temperature of wet surfaces, the evaporation rate can “double”.    

2 When drying a wall from the outside to the inside; EG heating ceramic tiles to cause the sheetrock to heat up causing evaporation inside the wall, negative air is necessary to empty the vapor from inside the space. This could be a tiny exhaust unit that needs to be equal to the amount of evaporation.   

3 Air movement is also used to help “surface” or “free” water evaporate. Air movement is affective on surface water, as the energy is able to get into each molecule relatively easy, spreading the water drops and causing friction (heat) which creates evaporation.

This is not true for “bound” water. Wind energy doesn’t penetrate into water, within the structure of wet materials, nearly as well as heat energy.

4 Moving air is also a factor in the operation of dehumidifiers.  Circulating air can push the warmer, wetter air, in the room, to the dehumidifier, ultimately drawing the excess vapor over the cold coils causing condensation (dew point) which causes…..dehumidification, removal of vapor. This vapor is now gone and won’t re-condense on wet surfaces.

5 Moving air can "help" prevent the growth of mold, on a water damage restoration job. Mold spores need to land on a food source and germinate to grow. If we keep the mold spore “moving” it has a tough time growing.   


NOTE: Moving air to inhibit mold growth only applies to areas where the level of mold is acceptable. Beyond a certain point, or “level”, containment and removal may be required. Do not blow air on, non contained, visible mold!


6 Another use for moving air can be evacuation. Evacuation, or “moving it out the window”, can reduce humidity and temperature. A thermostat plugged into a wall outlet can cause a fan plugged into the thermostat, to go off and on at pre determined temperatures, keeping heat “and” humidity at an acceptable level.

7 An Air Filtration Device (AFD) - Air Scrubber – also depends on air. Sitting in a room without movement from fans, placed in the room, an AFD operates on the basis of a “capture zone”. So many feet out and so many feet wide. Beyond this capture zone the unit has difficulty drawing in particles. To help an AFD capture more particles from more area in the space, additional airflow can be used to, essentially, make the entire room the “capture zone.”


Airflow doesn’t get credit for evaporation like it used to, in water damage restoration, but we still can’t do without it!


 Dennis Klager

Copyright 2012 by Dennis Klager