By Bob Baker

Spring, the time when good contractors are fully involved in getting customers cooling systems into top shape for the coming season. Hopefully all of you have more to do than you can get to every day. I pray that a good deal of your efforts are involved in cleaning cooling coils, blowers and housings, drain pans and other air-handler components. That is because a clean system is the single most important gift you can give a customer to assure a clean fresh home or office environment.

Although there are many factors involved in providing good indoor air quality, all are a distant second to having a clean system. In addition, to improved air cleanliness, a clean system will operate more trouble free and consume far less energy to provide the same level of cooling. It has been shown that a clean system can be over 30% more efficient than a contaminated one. There is no doubt that clean systems are very important.

Cleaning Is Difficult

As important as coil cleaning is, it can be very difficult and time consuming. Heavy sprayers filled with coil cleaner mixtures and water must be unloaded and hauled up or down stairs. Panels must be removed and often holes cut to gain access to parts to be cleaned. In many cases layer after layer of built up grime must be removed which often requires repeated application of cleaner and rinse water.

Also, system cleaning can be dangerous. The technician is repeatedly exposed to high concentrations of mold and bacteria that build up inside of air handlers. Technicians that do a lot of system cleaning have reported aggravated allergies, persistent upper respiratory infections and other nagging ailments. There are some reports of individuals becoming so sensitized that they can no longer work around air-conditioning equipment. In addition, the coil cleaner used can be either irritating or outright dangerous to use without respiratory and skin protection. Not only can a toxic cleaner endanger technicians, their use in an air-handler can leave behind residue that off gasses into the air stream and sickens occupants of the conditioned space.

Steps to Safety

Your first concern should be the safety of the technicians who will be cleaning air handlers. Based on what we have learned in the past several years, the interior of an air-handler should be considered a very high-risk space. Even a small air-handler such as would be used in a small home or apartment contains sufficient biological material that day after day exposure could lead to chronic respiratory irritation. There have been reported cases where the immune systems of technicians have become sensitized leading to total disability.

Technicians should be provided with both eye and respiratory protection and gloves to protect exposed skin. The organisms growing in air-handlers often include pathogens that can infect eyes, open cuts and sores as well as breathing passages. Such protective gear should also be satisfactory to protect against any toxicity associated with the coil cleaner used. Even so, it is a good idea to avoid cleaners that put off toxic or irritating fumes. Coil cleaner residues have been held responsible for several highly publicized indoor air incidents in office and other buildings.

Cleaner Selection

Manufacturers produce a wide variety of cleaner types. Each is well suited to different needs and cleaning challenges and there are tradeoffs between the various types. Your selection should be based on your needs, budget and the amount of risk you are willing to assume. These include:

Acid cleaners - These were once very popular because their relatively low price and ability to quickly clean extremely dirty surfaces. Today, they are mostly used on condenser coils and other exterior applications. This is because they give off noxious fumes that endanger both the user and occupants of a building. In addition, they work largely through a chemical reaction with the coil fin surface that can damage the fins and greatly shorten the life of a system.

Alkaline cleaners - These are formulated using potassium or sodium hydroxide (caustic) and are cheap and rapid acting. Although the fumes they put off do not tend to be as noxious as acid types, they can still be highly irritating. As a result these cleaners must be completely rinsed off before the air-handler is placed back into service. They also react with fin surfaces and so should be used only with older equipment where a shortened life and less efficient operation are not important issues.

Neutral cleaners - These have been formulated to overcome some of the limitations of the above cleaners. They use detergents and solvents or surfactants to clean and thus do not damage the air-handler components and release fewer irritating fumes (especially those that do not contain solvents). They are often called 'self-rinsing' because any residue left is less likely to cause odors or contaminate the building and will eventually rinse off as water that is removed from the air runs off the coil surfaces. Because of the more complex formulas, they can be more expensive.

Buffered cleaners - This is a new formulation technology. At least one manufacturer is producing a cleaner of this type. These clean as well as an acid cleaner yet contain no free acid and have the same pH as human skin (5). Thus they are very safe and non-irritating to use. This also means that they cause no damage to equipment and leave no noxious residue that can cause air quality problems. Because the formulas are complex and have more ingredients, they tend to be more expensive than other cleaner types. Many users feel that the significantly lower risk in using these, more than justifies any added cost.

Mr. Baker's field of expertise is the control of contamination in air-conditioning and ventilating systems by mold, mildew and bacteria. He writes and speaks frequently about the efficacy, legal risks, and regulatory issues involved in various control strategies. He serves on ASHRAE Technical Committee TC 2.3, TC 2.4, TC 9.8, and Sampling of Airborne Particulate Concentration in Commercial and Residential Buildings GPC 17P. He also serves as a member of ASTM D22.06 (Indoor Air Quality) and is on the Board of Directors of the Indoor Air Quality Association and the Florida Public Health Foundation. Because HVAC applications encompass new uses from an U.S. EPA regulatory standpoint, Mr. Baker works closely with the EPA and industry groups, including serving as the chair of the IAQ committee of the Consumer Specialty Products Association, to help formulate policy in this area.

Bob Baker is Chairman and CEO of BBJ Environmental Solutions, Inc., a company specializing in providing clean air through environmentally responsible products, such as BBJ MicroBiocide , BBJ Micro Coil Clean , "FreshDuct Odor Eliminator ", and BBJ Mold and Mildew Remover™ as well as the revolutionary new Power Coil Clean™. For additional information, Mr. Baker can be reached at (800) 889-2251 or through the company web site at http://www.bbjenviro.com.