Scrubbing The Air Clean
Air Scrubbers Can Be Panacea For Building Maintenance

The term "air scrubbing" has been bantered about quite a bit lately. However, air scrubbing is not really new technology for the indoor mold industry. We have used air-scrubbing techniques on projects for more than 30 years. I have found air-scrubbing to be very effective as long as common sense is applied. Air scrubbers are referred to as air cleaners by some people. Ozone generators have also been called "air cleaners," but they are not air scrubbers. What is an "air cleaner"? What is clean? How clean is clean? We know what air is. The term "scrubber" is self-descriptive. We are talking about reducing bioaerosols by filtering them out of the air; essentially, that is the function of air scrubbers.

The filter in an air scrubber is there to trap the bioaerosols that try to go through it. If you want to design an air scrubber, you would first you start with a squirrel cage fan assembly, commonly installed in a metal or plastic box. Some of them have wheels and/or handles to help with mobilization issues. Then attach an electric motor to the squirrel cage. Next, design the filter you specify to fit in the box, so that all the air drawn into the box has to go through the filter and out the exit portal of your air scrubber or air filtration device (AFD). We call air scrubbers AFDs at our shop. It should be noted that some manufacturers have designed air scrubbers to be promoted specifically for air scrubbing.

There are many manufacturers of AFDs that have referred to them as "negative air machines." A rose by any other name smells the same! Or how about, "If it looks like a duck, and quacks like a duck, it's probably a duck!" Call them what you like, but I haven't found one AFD that couldn't be adapted to be multi-functional, if not already designed to do so! With a little creative thinking and sheet metal, you can help control your destiny.

Filters are usually designed for HVAC systems in homes and workplaces. Filters are an integral part of a building's air-moving system, the HVAC system - the lungs of the building! However, you cannot put extreme filtration in a normal residential HVAC unit because of back pressure causing probable motor burnout problems. Just think of it this way, if the filter gets so dirty that air can't get past it, it would be like putting a piece of plywood, sheet metal, cardboard, or plastic over the filter bay. That would starve the intake portal of your HVAC return-air system and cause extra strain on your air handler's fan motor and coil system(s). This would probably burn out the motor sooner than necessary and is problematic, at best. So in essence, in almost every building, you can find air scrubbers; they're called filters.

Filters are a subject most people don't take time to study. In my quest for remediation perfection, I studied the air filter industry. My purpose, at that time, was to sell filters through my HVAC reconditioning company (we no longer operate that company). I thought it would be a good idea to know what was available and by whom. To my surprise, I could find over 200 manufacturers of filters, just in the United States alone. Of course, there is an air filter association. There's a whole array of technical information that has been compiled by the filter industry. They have ratings developed for filters that are tested in laboratories. Although my subject isn't filters, you must understand filtration capabilities before you can utilize air scrubbers to their optimum point of efficiency. I'll just touch on the fact that there are different sets of ratings for filters. It would behoove mold remediation contractors to conduct their own study on filtration before attempting to use it.

The filters that we are going to discuss in relationship to professional air scrubbers are almost always going to be what is referred to as HEPA filtration. I have heard different scientists interpret this acronym in different ways. As far as I'm concerned, they are High-Efficiency Particulate Accumulators. Particulate can be a grain of sand, a spec of drywall dust, a piece of fiberglass - any airborne solid particle. Mold spores are particulate, and they come in a variety of shapes and sizes.

Mold spores known to man range from 2 to 50 microns in size. They tell me you can fit over 2,000 microns on the tip of a needle. You won't be able to see airborne mold spores with the normal naked eye. There are thousands of species of fungi identified and studied. There are hundreds of thousands of fungi not yet named, let alone studied. Do you care what kind of mold is growing on your food in your refrigerator, or are you simply going to toss it in the trash? If the smallest known mold spore is two microns in size, I should be able to "trap" it in a HEPA filter. That's why HEPA filtration is recommended for mold remediation workers' respirator protection. HEPA filters are typically rated at 98 percent efficiency (or better) down to .02 microns. That's 100 times smaller than the smallest known mold spore. So what's the problem? Why can't we simply scrub the mold spores out of moldy buildings? We can reduce some bioaerosol problems to some degree with air scrubbers, but sometimes that's like putting a band-aid on a broken leg.

Air scrubbers can be the panacea of the hour as far as preventative maintenance is concerned. I have air scrubbers in every area of my home and office. The air scrubbers shown in the photos only slightly depict the various models and styles available today. I bought most of my non-commercial grade air scrubbers from Home Depot. I do not own any stock in Home Depot; there are plenty of other suppliers and manufacturers. The point is, air scrubbers are available to the general public on a wide-scale basis. It's no secret. The literature from Home Depot's brand called it an "air cleaner." It has the same design I previously described for commercial air scrubbers, only more compact and with far less capacity than my commercial air scrubbers. Typically, non-commercial grade air scrubbers designed for retail sales offer a variety of activated carbon filters in line with their pre-filter and HEPA filter. I have adapted activated carbon filters in my commercial AFDs for special projects.

Most all AFDs have one or two pre-filters, or they should. One is usually a more ornate mat type, low-efficiency filter. After that, you'll generally find a pleated pre-filter with a more efficient rating than the mat filter types. These "boulder catchers" cost substantially less than HEPA filters and promote longevity for the HEPA filter. We use our AFDs in a variety of ways. We can hook them up at a window of a building and use them to draw air in or out of that building. We can also place them in work areas and let them filter bioaerosols during certain phases of remediation. Some of the photos show our commercial AFDs at work on job sites.

Air Scrubber Uses
Air scrubbers can be used for more than one purpose at a time. For example, you can use air scrubbers to help direct work area airflow. I usually do not bring in our AFDs until after gross demolition is complete and the work area is "broom clean." We bring our AFDs in "cleaned and wrapped" with at least new pre-filters. HEPA filters can be expensive so we'll reuse them as much as practical. Your air scrubbers can and should be equipped with a built-in manometer and audible alarm to help alert you of back pressure build-up within your unit. This is caused by clogged HEPA filters. The alarm basically lets you know when you've filled up your air scrubbers' HEPA filter. Some air scrubbers do not have an audible alarm to warn you of an overloaded HEPA filter. I suggest that you etch in your pressure reading on all brand-new air scrubbers and filters. Etching a number on the pressure gauge at that time gives you a "best-case scenario." If you don't have an audible alarm feature on your air scrubber, you can monitor back pressure by the position of the manometer's gauge needle in relation to the original "best-case scenario" etching. This is not rocket science, but it works in the real world. I also check for any air bypass or leakage problems when a new AFD arrives at our shop and periodically.

I was asked to write this paper from a mold remediation contractor's point of view. To that end, I'll offer the following synopsis on various applications where I've used air scrubbers.

The first case study involved is a residential condominium unit in a multi-family building. This situation presents its own set of issues. One such issue is the fact that interstitial ceiling, wall and floor cavities in multi-family buildings are usually contiguous, as far as airflow. Each condo unit occupant sets their HVAC thermostat at their comfort level. We know that there are always different strokes for different folks. It is impractical to try to coordinate every unit's thermostat to be set identically. Additionally, thermal differentials, say for instance in the desert of Las Vegas can vary dramatically from the sunny side to the shade side or the first floor with the second floor. That means pressure differentials are uncontrollable without some sort of isolation. You must control the airflow in your work area - why not use air scrubbers?

Our second case study involved the use of air scrubbers equipped with activated carbon filters. The main 911 nerve center for the city of Las Vegas was on the verge of having to close down. The emergency generator for this facility was located in the basement, one level below ground. The 911 Control Center is located on the same elevation. The normal monthly maintenance was for this diesel-powered unit to turn on automatically in order to help keep the motor gaskets from drying out and assuring availability. A diesel line ruptured and diesel fuel entered the basement under the adjacent metal stud, fiberglass batt insulation and drywall wall. The diesel fumes were inundating the 911 Control Center employees. They were vomiting, and experiencing headaches and nausea. They were working with less than half of their normal staff by the time I got there.

I was called after the Las Vegas Fire Department tried to remediate this for almost two days. They gave me full reign over this facility. We opened up the outside wall at the basement level that separated the occupied space from the generator. The generator was located in a room vented directly to the outside with a metal security grill at the opening on top. It looked like a giant window well from the exterior. The mechanical engineer and I worked on controlling the buildings HVAC system. I asked for 100 percent outside air in and 100 percent return air out. We pressurized the 911 level to help blow out the lingering fumes through the outside walls we opened up. I set air scrubbers intermittently throughout the 911 level. I ordered rolls of activated carbon filter matting and fit it to our air scrubbers. The 911 area was clear within 48 hours.

Our third case study involved a 250,000 square foot state government office high-rise with six stories. Our governor's Las Vegas office was in this building. The Nevada State Gaming Control Divisions' main secured office area is the subject of this article. These offices were equipped with portable cubicle dividers throughout their space. We were called over one year after this building opened. Sick Building Syndrome (SBS) was rampant and tempers were frayed. The employees working in these areas wanted answers. Our mission was to research probably causes and recommend solutions. This required access to their ceiling plenum. They have a suspended metal grid with 2' x 4' acoustic tiles. This ceiling plenum is their return air system. This office has employees in and out 24/7. In the past, others suffered consequences after aerosolizing dust from the ceiling plenum into these occupied spaces. We decided to construct a portable work area the size of a ceiling tile (2' x 4'). We call it our PIE (Personal Isolation Enclosure). We put extensions on our vertical posts to adjust for different ceiling heights and wheels on the plywood platforms. I designed this unit to be just big enough to place a commercial-grade stepladder inside. We wrapped our PVC frame with two layers of 6 mil visquine and hooked up an air scrubber on wheels. This gave us portability and a negative pressurization inside the work area box we made. I guess you could call this "thinking inside the box." This allowed us to open the ceiling without allowing plenum dust into the occupied space, except through our air scrubber. The air from the ceiling plenum was filtered before it exhausted into the occupied spaces.

John Terranova, CMH, WLS is president of Terranova Mold.Com in Las Vegas, Nev., and is a nationally renowned as one of the indoor mold industry's leading remediation consultants, as well as for inventions he created through research and development. You can reach him by calling (866) 387-4526.

According to recent media reports, Rep. John Conyers Jr., D-Detroit, has finished a federal mold protection bill and plans to introduce it on the House floor this month. Details were sketchy as of press time, but IE Connections has confirmed that the legislation will propose that mold remediation professionals be licensed and government agencies, EPA and the Centers for Disease Control & Protection (CDC), would be required to develop safe standards for mold levels. No word yet on whether Conyer’s has gained Republican support for the bill in the Senate.

Over the last year, both agencies have weighed in on the mold contamination issue through the production of basic consumer and industry guidelines for remediation practices. Aaron Trippler, director of government affairs for the American Industrial Hygiene Association (AIHA), told attendees at last month’s Healthy Indoor Environments Conference, that although the Conyer’s bill is something that AIHA will closely track, he doesn’t expect mold to become an election issue this year.

“Interesting that this issue seems to have appeared overnight as far as policymaking goes. Reminds one of the rush to asbestos abatement years ago,” he said.

Indeed, most industry experts IE Connections spoke to say that even if the Conyer’s legislation becomes law, the wait for licensing and federal mold guidelines could be arduous.

“Look at what the government did with lead poisoning,” said one industry professional who asked not to be named. “Most of the science was already there and it still has taken over 10 years for the amendments of Title X: The Lead Poisoning Protection Act to be finally enacted. And the government agencies are still working on it.”

David Jacobs, director of HUD’s Office of Healthy Homes & Lead Hazard Control, told Healthy Indoor Environments Conference attendees that the real question that needs to be answered is when does the moisture become so excessive that it produces a level of mold growth that is dangerous to human health.

“This is the question that must be answered. But I have to be straight with you,” he said. “We do not have nationally recognized standards for mold and for moisture control in houses right now.”

The Conyer’s legislation is expected to:

• Have the EPA and CDC establish guidelines specifically stating what level of toxic mold is acceptable and what level is dangerous;
• Require states to license and monitor mold inspectors and remediators; and
• Require additional research into mold contamination by the EPA..

Word On The Street

IAQ Publications Founder Dies: Larry Siegelman, 47, president and CEO of IAQ Publications in Bethesda, Md., died March 31, 2002, of cancer. He is survived by his wife, Jill, and his son, Jacob. He was founder of the company that brought indoor environmental news and information to a higher level, publishing more than seven trade newspapers and newsletters, creating five separate conference and exhibition series, and developing industry directories and special reports. His former titles included The Radon Book, Indoor Environment Review, Lead Detection & Abatement Contractor, Building Environment Report, and the Lead Tech and Indoor Environment conference series. In 1999, Siegleman, and business partner Robert Morrow, combined all of their publications into one– Indoor Environment Business– and sold it to publisher, Adam Goldstein of Potomac, Md.

Paul Davis Goes with CMR: The New England region of the Paul Davis Restoration franchise organization has selected the Indoor Air Quality Association (IAQA) Certified Mold Remediator (CMR) training and credentialing program for its representatives. A series of five or more private classes will be scheduled with an IAQA-approved Course Provider this summer, who will teach the 2-1/2 day program to groups of 30 or 40 restoration professionals.
About 100 Paul Davis Restoration employees from around the nation have already been through the CMR program. “Members of the franchise network gave real positive feedback about the CMR program to corporate decision-makers, which led to the New England region going with IAQA’s program. We are hopeful that Paul Davis Restoration’s national franchise office will soon advocate CMR for their franchisees world-wide,” said Farzana Shakir of IAQA.

Expensive Smokes: Each pack of cigarettes sold in the United States costs the nation an estimated $7.18 in medical care costs and lost productivity, the Centers for Disease Control and Prevention (CDC) reported last month. In a study of deaths related to smoking, years of life lost, and economic costs, CDC found that smoking continues to be the leading cause of preventable death in the United States, resulting in an estimated 440,000 premature deaths annually from 1995 through 1999.

Get Your Mold Off My Property: Residents of Montgomery County, Maryland can soon complain to the county about indoor air pollutants, and polluters may be fined up to $750. The County Council passed a bill last month regulating indoor air pollutants such as dust fibers, asbestos, carbon monoxide and molds. Tobacco smoke was left out as an irritant despite vigorous lobbying by anti-smoking activists. An earlier version of the bill would have allowed the county to fine residents whose cigarette fumes spread to a neighbor’s property. The County Executive is expected to sign the latest version into law.

Latest Celebrity Mold Case: Ed McMahon has filed a $20 million lawsuit against his insurance company, American Equity Insurance Co, two insurance adjusters and several environmental cleanup contractors, claiming he was sickened by toxic molf that spread through his California home. The suit seeks damages for alleged breach of contract, negligence and intentional infliction of emotional distress. McMahon and his wife also claim that they became seriously ill and their dog died from mold-related illness. The home is currently being remediated.

No New Home Policies: They may not be involved in the Ed McMahon case above, but the rising cost of mold-related claims has caused State Farm to stop writing new homeowner policies in California beginning this month. The State Legislature currently has two proposed bills that would essentially require insurers to keep the homeowner’s level of coverage that’s now standard, and forbid many requested restrictions by insurers. Currently, most insurers in the state cover mold cleanup if it is part of a claim for sudden and accidental water damage, such as a pipe bursting.

New ASHRAE Lecturers Named: Ten new distinguished lecturers have been named by ASHRAE, providing ASHRAE chapters with noted authorities who provide insight and speak on relevant topics that impact the HVAC&R industry. The new lecturers, who will serve a two-year term, include:

• Donald Colliver, Ph.D., P.E., University of Kentucky, Lexington, Ky., Advances in Design Weather Conditions and Tools. Colliver will serve as president of ASHRAE for 2002-03.
• Donald Gatley, P.E., Gatley and Associates Inc., Atlanta, Ga., Fun with the Invisible Substance Water Vapor - Myths, Puzzles and Fundamentals for a Lifetime; and Psychrometrics - From Forgotten Fundamentals to Practical Applications.
• Daniel Int-Hout III, Carrier Corp., Carrolton, Texas, Designing for Occupant Acceptance; Avoiding Sick Buildings While Assuring Occupant Productivity and Building Optimization; and Selecting VAV for Acceptable Indoor Air Quality.
• Alan Veeck, Tidewater Air Filter, Virginia Beach, Va., How to Clean Up the Indoor Environment - ASHRAE 52.2 Filter Testing Standard and How to Engineer It; What's in the Air? Solutions for Indoor Environments in New and Existing Buildings; and Air Filters 101 - A Short Course in the Principles and Applications of Low, Medium and High Efficiency Air Filters.

IICRC Gets Media Exposure: Phones at the Institute of Inspection, Cleaning and Restoration Certification (IICRC) are ringing off the hook thanks to a carpet cleaning feature in the May issue of Good Housekeeping magazine. The article gives tips for selecting a carpet cleaner and information on the IICRC referral line and website.

Valenti Launches New Company: Susan Valenti, a publisher in the indoor air quality industry since 1992, has sold her interests in Indoor Environment Communications and the newspaper Indoor Environment Connections, and has launched a new company. IAQ Media Group will produce the Healthy Indoor Environments Conference series, publish a consumer indoor environmental magazine and website, and provide marketing and media services to clients in the IAQ industry. The company currently has offices in Madison, N.J., and Silver Spring, Md. As a founder of IE Connections, Valenti will retain the title of publisher emeritus for this newspaper.

In a March 2002 letter prepared for distribution to IAQ professionals and cleaning contractors, the U.S. Environmental Protection Agency (EPA) expressed concerns about the use of antimicrobial products in HVAC systems, and provided clarification regarding registration for products to be used in that application. The letter was sent to dozens of industry trade groups and publications for dissemination to their members and readers. The letter was written by Marcia F. Mulkey, Director, EPA Office of Pesticide Programs.

The primary purpose of the letter was the draw the distinction between antimicrobial products registered for hard surface application versus products registered specifically for application within HVAC systems. EPA wants to make sure the only products used in HVAC system cleaning are those registered for that use. The general hard surface registration is not sufficient for HVAC applications, since EPA “has not assessed whether such products are efficacious when used in HVAC&R systems.” EPA also expressed concerns about their safety in HVAC applications.

Some products that are not registered specifically for HVAC use may still list HVAC applications in their directions. “Even in circumstances where labels do list HVAC&R systems as a possible use, we are concerned that the Agency has not received and reviewed adequate data to fully evaluate risks to building occupants or product efficacy in that use pattern,” says EPA.

All of the cautionary language in the EPA letter is intended for antimicrobial products that lack the specific HVAC application registration. But that distinction is hard to see in a letter that attempts to explain a complicated system to an audience that may not be familiar with the EPA registration rules and regulations. Some IE Connections readers initially misread the letter to mean that no antimicrobial products should be used in HVAC systems.

“I have heard the letter referred to as confusing, and on the surface it is,” said Bob Baker, CEO of BBJ Environmental Solutions, Inc., a manufacturer of antimicrobial products. “When you understand the requirements of the law and regulations – FIFRA – that EPA must work under, the letter is as clear as it could be.”

Most manufacturers say the EPA letter was a positive development. “If [the letter] discourages the illegal use of products not properly registered by EPA for use in HVAC systems, then it will have proven useful,” said Archie Nahigian of Sporicidin International. Even manufacturers whose products aren’t registered for HVAC application are pleased with EPA’s letter.

“We are encouraged that the EPA has taken a proactive position, and is interested in better serving our industry,” said Andre Weker of Fiberlock Technologies, Inc. Fiberlock offers a line of mold remediation products, but says the company has refrained from marketing its sanitizers and disinfectants for HVAC applications, “until more definitive information and regulations/guidelines are established.”

Initial concerns that the EPA letter might dissuade some contractors from using products that are properly registered for HVAC applications appear to be unfounded. In fact, the letter may have the opposite effect. “The EPA letter has ultimately increased the demand for Oxine, one of the few products specifically registered for air ducts that has such a long and successful track record,” said Katie Moody of Bio-Cide International, Inc. Oxine has been registered for use in air ducts since 1988 and is one of the most commonly used HVAC sanitizers.

Other manufacturers echo Moody. “March 2002 produced record sales results, and we forecast no slowdown in business or loss in customer confidence,” remarked Harry Certain of Foster Products Corp.

The EPA letter begins a long road of research and education about HVAC antimicrobials. “Eventually, it will have a very positive impact on proper use of products because it will lead to discussion and debate that will serve to educate users. It also provides an incentive for manufacturers to provide more specific label language and use directions,” said Baker.

The EPA letter also opened the door for dialogue between the contracting community and the agency – something that has been sorely lacking in recent years. According to Aaron Mindel, executive director of the National Air Duct Cleaners Association, “A number of questions were raised by the letter so NADCA has scheduled a meeting with the EPA to discuss the letter in more detail, and to obtain the Agency’s position on some issues. We will also offer the associations’ assistance with this matter.”