BBJ's Robert Baker cautioned on the use of cleaning products in ventilation air ducts.
KISSIMMEE, Fla. - What would an hvac convention be these days without a discussion of mold? And where better to have this discussion than in warm, humid, central Florida?

As an hvac contractor, what do you need to know about mold, and what is the role of the sheet metal fabricator/installer?

Henry Berman, TRI MED Environmental Research Co., Carmel, Ind., said that in many sick buildings the central hvac system has become the "heart" of the problem. "The response to these new indoor challenges was to modify building codes that require the entrance of more outside air to create a greater air exchange," Berman said. "This however adds additional pollutants including various species of mold and fungi.

"Duct systems act like a body's blood vessels," he said, "routinely distributing conditioned air throughout a building, becoming the very pathways which microbes can be carried from these reservoirs to distribute through the building." Also, drain pans that are built into a system to trap condensate, blower housings, baffles and louvers all can serve as reservoirs of microbial colonization.

Berman was one of a panel who spoke on mold at the 34th annual Air Conditioning Contractors of America (ACCA) conference here February 27-March 1.

The interest in mold is making it one of the most prominent and potent of indoor air quality problems. According to Berman, after news of floods or other such disasters, many attorneys are known to call potential clients with offers of free mold testing. And many people who never suffered from allergies before are suddenly becoming allergic due to mold exposure. "Allergies are like a bucket that overflows with one more drop," he said, adding, "Filtration is not enough."

Berman's company advocates the use of carefully controlled amounts of ozone and the use of a germicidal ultraviolet light to kill airborne mold spores. In an experiment, the ozone generated did not exceed OSHA levels for an occupied space, he said. The resulting "low cost air purification system" his company developed, he said, was found to be safe and effective in reducing mold spores.

It is tempting, said Robert Baker, BBJ Environmental Solutions Inc., Tampa, Fla., but potentially hazardous, to spray the inside of a duct system with an antimicrobial to kill existing mold spores or airborne pathogens. But most, if not all, of these cleaning agents are not meant to be aerosolized, or breathed in. Some, such as gluteraldehydes, used for sterilizing medical instruments, are carcinogens and should be used only under controlled conditions.

Some of the audience members wanted to know what precautions hvac employees should take in remediating mold: respirators were advised, and, in extreme cases, full body protection including Tyvek suits.

Limiting liability

Meanwhile, PHCC member Sam Dowdy of S & D Plumbing in Taylor, Texas, has developed a mold liability agreement that he has agreed to share with PHCC members. One passage of note reads: "Customer assumes the risk of all damages or injury to property or persons from mold or mold related Claims resulting from the Plumbing Services? Owner hereby acknowledges that Company has not made any representations to Owner regarding the extent or potential of mold which may or could result from the Plumbing Services nor the consequences of mold which may or could arise, and the conditions which may result in mold and this Agreement is to assure the Company that it can undertake the Plumbing Services without liability for any known or unknown conditions which may result in mold."

The disclaimer stems, in part, from a decision by the Texas Insurance Commissioner to stress consumer choice on mold-related insurance coverage. The new order reportedly retains coverage for removing mold related to water damage, but it eliminates coverage for higher priced procedures, such as testing, treating, containing or disposing of mold which that which is necessary to repair or replace property damaged by water. "Such procedures have contributed to unexpected and dramatic premium increases," he said, according to an article in the Invironment Professional newsletter for January ("Texas Strives for Balance in Mold Insurance").

To see the complete document, visit Dowdy is a member of the PHCC Texas Task Force on Mold Issues.

In other "moldy" news:

  • PHCC Texas has developed a list of helpful mold prevention tips for customers; phone 800-533-7694 for a faxed version.

  • The National Air Filtration Association (NAFA) held a technical seminar in Nashville, Tenn. last month with a day-long condensed session on mold remediation. For information on future seminars contact NAFA at 202-628-5328; or visit

  • Air Quality Sciences Inc., Marietta, Ga., states that remediation procedures for a moldy building should concentrate on removal of the mold rather than the use of biocides and disinfectants. Use of such chemicals is unnecessary unless infection is perceived as a health concern, according to AQS. Air samples may be taken and analyzed by an accredited laboratory. "The primary goal of remediation is to remove or clean contaminated materials while preventing the distribution of spores into clean areas and protecting the health of workers." A seminar on mold remediation was held last month in Austin, Texas. For information on future seminars contact them at 770-933-0638 ext. 232.

  • From the Light + Building trade fair in Frankfurt Am Main in Germany in April '02 comes a report on "air humidity levels, a crucial matter in health provision." Studies have shown, according to the report, that a relative humidity of between 40-60% is ideal, "although many doctors narrow the range further to between 45-55%." On proper humidification, the report states: "In any room, we find air that is too dry and that which is too humid unpleasant? Since dry air can hinder oxygen intake and oxygen during the breathing process, it can easily lead to a person feeling unwell, to tiredness and lapses in concentration."

  • The Indoor Air Quality Association offers a Certified Indoor Environmentalist (CIE) and Certified Mold Remediator (CMR) program. For example, when last we checked the website,, there were 16 CMRs listed in Michigan, 118 in Florida and more than 200 in Texas. The group also is holding a convention in Orlando, Fla. October 2-5. Call IAQA at 301-962-5070.