Reduce IAQ Liability and Increase Profitability: Advantages for Architects, Engineers, and Building Owners

By David P.W. Solberg, P.E., President, HVAC Systems Technology, Inc.

Verifying that ventilation rates meet the national Standard is cheap IAQ insurance and a smart investment. Since the middle1980s tighter building construction has dramatically reduced infiltration through the building envelope. Also during this period the increased use of variable air flow/volume (VAV) ventilation systems has unintentionally reduced the outside air distributed through the supply duct_1,2,3. Both of these factors have reduced the dilution rate for contaminants emitted from people and the building and have been a major factor in degrading indoor air quality (IAQ) to levels that are 100-1000 times more polluted than outside air₄. Since people typically spend 90% of their time indoors_5,6 IAQ has become a worldwide concern.

In 1998 the United Nations attributed 2.2 million deaths/year from indoor air pollution, more than 4 times the mortality rate for outdoor air pollution₇. A 1997 joint study between the U.S. Department of Energy and Lawrence Berkley National Laboratory estimated total costs to the U.S. economy range as high as $168 billion/yr₈. The report attributed $6-19 billion from increased respiratory disease, $1-4 billion from increased allergies and asthma, $5-10 billion from sick building syndrome, and a potentially huge amount, $12-125 billion, from reduced productivity. In 1998 the EPA reported 50% of U.S. schools have IAQ problems₉ and a report commissioned by the National Contractors Association found that 15-35% of U.S. office buildings have significant IAQ problems₁₀. U.S. asthma rates have escalated since IAQ problems have become prevalent₁₁. Several studies link IAQ and respiratory symptoms in homes, schools, and office workers _{12,13, 14,15}. Children and hospital or health care patients are especially susceptible due to their underdeveloped or compromised immune systems. In 1999 the New York Times reported an asthma rate of 38% for children in New York City shelters (with notoriously poor IAQ)—more than six times the national rate for children₁₆.

IAQ liability has also become a major consideration for the construction industry. In 1996 Owen McGowan of the law firm Mitchell, Heilein, and DeSimions commented, "virtually unheard of until the mid-1980s, problems with indoor air quality are growing in frequency and severity"₁₇. More recently, in 1998 the New York Law Journal reported a "deluge" of sick building syndrome claims₁₈. IAQ claims and awards can easily run into millions of dollars_17,19.

A 1997 study of 8600 claims by DPIC, the second largest U.S. insurer of liability insurance programs for architects, engineers, and environmental consultants, revealed the dominant role of HVAC (heating, ventilation, air conditioning) claims₁₉. HVAC problems represented 61% of the total claims dollars paid by DPIC and 47% of the total number of claims for mechanical consulting engineers. For architects, DPIC claim dollars paid out represented 6% of claims dollars paid and 7% of the number of claims. During the study period DPIC paid out $18.4 million in 44 claims in behalf of the insured mechanical consulting engineer and architect policyholders. An additional $7 million was paid by other parties such as contractors, vendors, other design professionals not insured by DPIC. Many claims are settled out of court since the cost of litigation is considerable20. Furthermore, insurance companies have written policies that deny coverage based on a "pollution exclusion" clause_18,21,22.

The IAQ dilemma is similar to that experienced with tobacco and lung cancer. Ample evidence is available to establish a cause/effect relationship, but vested interests cloud the issue by focusing on ambiguities. There is by no means universal agreement of what constitutes IAQ, much less what the quantitative relationship is between IAQ and productivity. However, this should not prevent anyone from making a seasoned decision based on the overwhelming trend of existing research. A brief explanation of IAQ and its relationship to productivity will eliminate some ambiguity.

The current trend is to view IAQ as one group of many stressors on humans. Environmental stressors include IAQ, lighting, temperature, humidity, and air movement (drafts). Worker satisfaction, management relationships, ergonomics, and ability to control ones environment are also stressors. Any single stressor can influence perceived IAQ and skew productivity studies.

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