HVAC Systems Microbe Contamination Frequently Asked Questions

How does the air contitiong system inside a home become a source of microbial contamination..?
Can you prevent the growth of these biologicals…?
What is in it…? What kind of coil cleaners are there…?
I hear caustic and corrosive cleaners are much more effective. Why not use them…? Can keeping my system clean and free from growth provide other benefits…?
Why would a growth free system last longer…?

How does a typical home air conditioning system work?

A. A typical system functions as follows: air is drawn from the room through a return grill and passes through an air filter and into a furnace (or air handler). Inside of the air handler (which may be located in the basement, garage, a closet or in the attic) is the circulating blower, and a heat exchange coil commonly called the evaporator. The evaporator is cold and thus removes heat from air that blows across it. In addition to removing heat, water also deposits on the evaporator surfaces. The cooled air returns to the room through supply ducts and outlet grills. The moisture falls into a drain pan under the evaporator and drains through a pipe out of the system.
Q. How does the air conditioning system inside a home become a source of microbial contamination?
A. The air drawn into a system contains dust, much of which is biological spores and other organic particles. Even the best filters capture only part of this material. Much of the rest falls out of the air stream onto the heat transfer surfaces. It combines with the water and the spores germinate and grow rapidly (or amplify).
Does microbial contamination in my air conditioning system impact the quality of the air in my home?
A. Yes. ‘Contaminated central air handling systems can become breeding grounds for mold, mildew, and other sources of biological contaminants and can then distribute these contaminants through the home.’ (The Inside Story-A Guide to Indoor Air Quality published April 1995 by the U. S. Environmental Protection Agency).

HVAC system components can act as direct or indirect sources of particles and/or volatile organic chemicals (VOC’s). Of greatest concern is biological growth and bioaerosol generation, most of which are potential allergens. Airborne allergens in the home constitute one of the hardest types of allergens to avoid. Unfortunately, heating and air conditioning systems are excellent harbors for molds, and with vents in every room this same system is an efficient distribution system.

Q. Can you prevent the growth of these biologicals?
A. Keep your system clean and treated with BBJ MicroBiocideT a broad spectrum antimicrobial, which not only kills microorganisms (i.e. mold, mildew, fungi and bacteria) in the HVAC system but will inhibit their growth for up to 6 months. It is the only product registered with the EPA for use in air conditioning and humidifying systems.
Q. What is in it?

The Active Ingredient is, 2 Bromo 2 Nitropropane 1,3 Diol, which has been used for over 20 years as a preservative in Baby Wipes, Cosmetics and Shampoos, to ensure contamination does not grow while on the shelf.

Q. My HVAC contractor says my coils need to be cleaned. What kind of coil cleaners are there?
A. Coil cleaners are generally described as acidic, caustic or pH balanced. Acidic (or corrosive) formulas have a pH below 2. Caustic (or alkaline) formulas have a pH of 14. The chemistry of both is highly reactive to metals, especially aluminum, which most coil fins are made of.
Q. I hear caustic and corrosive cleaners are much more effective. Why not use them?
A. The problem is that the coil fins are easily etched by both low and high pH formulas. They actually remove some of the metal, leaving the surface pitted. This prevents water from easily shedding off the fins. These water droplets attract microbial growth and feed it and water droplets are then carried into the air stream and deposited downstream into the ducts, supporting secondary growth. In addition, these cleaners will give off fumes that are air contaminates. Coil cleaners which fall in the category of pH Balanced will not damage the coil while cleaning or release toxic fumes.
Q. Can keeping my system clean and free from growth provide other benefits?
A. Most people believe that systems free of growth operate more economically and last longer.
Q. Why would a growth free system last longer?
A. Most corrosion in HVAC systems is caused by sulfuric acid secreted by common bacteria that chemically combines sulfur from the air with hydrogen and oxygen from water.

About Mr. Baker: A national authority on the impact of bacterial and fungal contamination on indoor air quality, Robert G. Baker sits on several key industry technical committees. Mr. Baker, Chairman and CEO of BBJ Environmental Solutions, Inc., founded the business in 1993 following the EPA’s registration of the company’s central product, BBJ MicroBiocideÔ, a unique product that controls microbial contamination and that can make indoor air safer to breathe. Baker’s experience with hospital disinfectant manufacturing and as a high-ranking hospital administrator, corporate manager and planner has contributed to his new venture’s success.

For additional information, Mr. Baker can be reached at (800) 889-2251 or through the company web site at http://www.bbjenviro.com.