The AFD: Your Latest Service Offering
May 18, 2011
As recently as 10 or even 5 years ago, most restorers would not expect to use an air scrubber or air filtration device on most of their jobs.
We were well aware of air pollution being unhealthy, but usually associated it with big factories belching smoke and particulates into the air or the exhaust from thousands of automobiles fouling the air of big cities. We were more concerned about scrubbing the walls, ceilings and contents on a fire-loss jobsite, and on a water loss we were occupied with getting the structure dry before mold became an issue.
Then we began to learn about microorganisms that could become airborne during restoration, remediation and even routine cleaning activities. We learned that tiny particles in the air following a structure fire were a health hazard. These particles could be a mix of toxic hydrocarbons, hydrogen cyanide, oxides of nitrogen and other particles in the 2 to 20 micron range that could be inhaled deeply into the lungs, resulting in irritation and damage to the respiratory system. Asthma and other illnesses would be aggravated, and there could even be an increased risk of heart attack.
The threats from these invisible particles threatened both technicians and building occupants; not something to be taken lightly.
As restorers became better informed about the science behind air filtration, AFDs became more common not only on Category 3 water losses or mold remediation scenarios but on fire jobs and all water losses. The IICRC S500 Standard and Reference Guide for Professional Water Damage Restoration states that restorers can install one or more air filtration devices, depending upon the AFD’s size and obstructions within the structure. AFDs provide additional airflow, while simultaneously removing aerosolized soils or contaminants from the air within a room.
AFDs are rated by the number of CFMs (cubic feet per minute) of air that can pass through the unit while still performing as intended. The volume of air within the air being treated is compared to the capacity of the AFD. One, two, or more air exchanges per hour may be appropriate according to circumstances.
HEPA filters used in AFDs are usually sufficient to assure that air is healthy to breathe and the environment is left in a pre-loss (or better) condition.
AFDs can also be used to create negative air pressure inside containment areas. When negative air pressure is maintained, air is trying to enter the contained area rather than contaminated air flowing out of the space.
These days, even professional carpet cleaners are adding AFDs to their regular cleaning regimen. It’s a great example of the higher level of service that many customers are looking for. Explaining to the customer that you offer this extra service, that you contain and remove airborne contaminants while cleaning, gives them an extra feeling of safety and security, as well as leaving their home fresh and odor free when the cleaning is done. With the advent of smaller AFDs and HEPA filters that can be added to an airmover, both drying speed and air can be enhanced at the same time.
The recent release of US Department of Defense technology used to prepare for chemical and biological warfare, HAZMAT and anti-terrorism has opened new development doors for AFDs. There is, for example, a new system that utilizes air scrubbers, nanotechnology and earth mineral crystals for a fast, effective, non-invasive solution to odor problems. Earth minerals (metal oxides) have been used for years for odor control in large areas, but have been a problem for small structures and confined areas due to the small surface area for the odors to be attracted and destroyed. Nanotechnology first solved this problem by crushing the minerals to increase the surface area. This, however, creates a problem of adding particulate to the air, which can add to the IAQ problem rather than solving it.
The latest progression has been to actually grow minerals in such a way as to increase the surface area many fold, but not create a respirable particulate. An analogy would be something like using a kernel of popcorn before popping and after. Obviously, a popped kernel has a huge surface area compared to an un-popped kernel. This increased surface for the chemical reactions to destroy odor molecules is what makes the process that much more effective. Since the process removes and destructively absorbs airborne odor-causing molecules and retains them inside a cartridge, it is safer and “greener” than methods that generate or release chemicals into the environment.
All odor control procedures should start with locating and removing the source, but as technology continues to advance, AFDs will become as crucial for the professional carpet cleaner to keep at hand as they’ve been for the restoration technician.