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Air Maintenance Corp.
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MOLD & AIR FILTRATION:
MOLD HEALTH EFFECTS
Certain types of mold are considered toxic and can cause serious health effects. These species include
Stachbotrys chartarum, Aspergillus versicolor, A. flavus, A. furnigatus and Fusarium mortiliforme. Stachybotyrs Chartarum is a greenish-black mold that forms in environments with high moisture such as those that have water damage, water leaks, excessive humidity, condensation and flooding. The health effects of Stachybotyrs Chartarum range from sort-term irritation to extremely serious illnesses. Stachybotyrs Chartarum can produce mycotoxins that can develop into an indoor air quality problem. Stachybotyrs Chartarum has the potential to cause symptoms such as coughing, wheezing, runny nose, irritated eyes or throat, skin rash or diarrhea.
MOLD DISTRIBUTION
When considering mold control, air filters serve the purpose of limiting the amount of spores in a given volume of air, thus limiting the reproduction capabilities of the mold. Mold needs three things to survive: appropriate temperatures, nutrient (food sources), and water. All three of these items are indigenous to an HVAC system. Typical HVAC system temperatures range from 52'F to 140'F. Airborne contaminants, including molds, can become nutrients for other airborne molds, and water may be common in the area of coils or actually introduced through humidifiers. Proper application of HVAC components per the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAI) recommended practices serves to limit the possibility of contaminant growth within a system. The two most important considerations are the removal of contaminants (nutrients) and moisture. The presence of mold in buildings is becoming more common due to more airtight construction practices that improve insulation and energy efficiency but precipitate moisture in walls and ceilings. Mold spores are well over 1.0 micron in size and are easily removed by applying air filtration according to ASHRAE recommendations. Even a pleated panel filter with a Minimum Efficiency Reporting Value (MERV 6) per ASHRAE filter Testing Standard 52.2 will have an average efficiency of more than 80 percent against most molds. One key consideration is that air must be moved through the filter for the filter to remove the contaminants. If elevated mold contaminant levels are suspected, increasing the air changes to the space may have a debilitating effect on the mold's reproduction. As more air is moved through the air filter, the removal efficiency of the total space contaminant is increased. If a health situation exists specific to a species of mold, the application of proper air filtration with appropriate air conditioning system operation can reduce exposure. Mold requires a higher level of filtration efficiency for removal because of its smaller particle size. The chart below lists some common mold species and the filter efficiency that should be applied. The most important component of control is the limitation of water in the environment and in the HVAC system. ASHRAE recommends that spaces have a controlled humidity level of under 60 percent. Consistently exceeding this level is a prescription for problems. Try placing a slice of bread in a dish with some water next to a slice of bread on a dish alone and watch the result. 'RELATIVE MOLD SIZE & REQUIRED FILTER EFFICIENCY'
CONCLUSIONS & RECOMMENDATIONS
TO PREVENT MOLD PROLIFERATION IN YOUR BUILDING:
Control growth at the source by:  If mold is discovered, fix the source of the problem. In most cases, the best level of control requires the complete removal of the contaminated items. This may include complete replacing wallboard, sheet rock, and carpeting or damaged organic materials (wood-bearing products). Light instances of contamination may be cured using a weak bleach solution. In this case, you must assure that the contaminated item be allowed to dry completely.
The control of mold in our environment requires diligence and the application of good building and HVAC system housekeeping. The key to air quality control in any application is to maintain contaminant dosage at acceptable levels, whether the level is sensory or definitive based upon a health guideline. Air filtration always plays a major role in this arena. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molds, mildews, bacteria and dust mites, all sources of allergic reactions within our species, like the same environmental conditions that we do, warmth and moderate to high humidity. Mold needs little more than a constant moisture supply for survival. Water-damaged carpets, ceiling panels, walls, and paneling are prime sites for new growth if they are allowed to stay damp. When molds and mildew are disrupted, they release their spores into the air and the result is a bioaerosol formation.
