In Vol. 97-02 of Industrial Hygienist, we described the revised draft of the ASHRAE Standard Ventilation for Acceptable Indoor Air Quality as a fascinating document that contained many common sense elements to control air quality problems. Fresh air ventilation was the name of the game, and everyone in the air quality industry seemed to agree. It appeared that at least one significant air quality initiative would emerge in the last decade of this century, in what has been a rather unimaginative period in environmental problem solving.

Alas, the revised Standard proved to be too ambitious, and has been withdrawn in a storm of controversy. The many new elements were criticized by HV/AC equipment manufacturers and design engineers as being unproved, too daring, and too expensive. Industrial hygienists complained about removing CO2 testing from the ventilation standard. Everyone was afraid that the version of the draft in Code language would serve only to keep the courts busy and the lawyers wealthy.

So the draft was withdrawn, and the 1989 Standard will be revised piecemeal under a continuous maintenance procedure. It is not clear what this means, and there have been no appreciable revisions in more than a year. It is likely that the ASHRAE committee was blind-sided by the response during public review, and is now loath to publish any changes. We encourage the committee to be brave, and proceed with changes as follows:

1. Immediately reinstate the Minimum Supply Rate concept for fresh air, show the tables and keep the calculations. They are not complex, and address almost all of the conditions that are commonly encountered in buildings.

   Many have protested that there is disagreement over how to measure fresh air flow, and this is a fact. It can be done, however, and manufacturers can make it easier with better designs. So let's get it done, and build equipment that actually delivers the goods. Experience will show the way.

2. Eliminate the Air Quality Procedure. This alternative approach lists acceptable levels of airborne contaminants that nobody in the industry accepts anymore. It has simply become the way to avoid the fresh air requirements of the Standard.

   The AIHA protested the removal of the alternative procedure, wanting to add sections which "address provisions for recognizing IAQ problems, including test methods." Why would air testing methods appear in a ventilation standard? The AIHA should be glad that ASHRAE got out of the air testing business, applaud the beautiful job ASHRAE did in its Appendix C Air Quality Guidelines, and dig in to help resolve the testing problems that plague IAQ investigations:

   1. Why is CO2 testing so unreliable?
   2. What is a good TVOC number?
   3. Is there a simple tracer gas method?
   4. Is anybody going to publish a practical guide for mold?

   ASHRAE did its job. It is time for AIHA (or maybe ACGIH) to do theirs.

3. Some specific elements of the draft may currently be impractical , and perhaps should be modified with more general language. Examples are humidity control in humid environments, methods to measure and control fresh air intake in VAV systems, and the use of CO2-based demand control ventilation systems. These are not issues that are fundamental to Items 1 and 2, and should not prevent their immediate implementation. The danger of allowing the draft changes to languish in committee, of course, is that local codes and standards which are the basis of air quality enforcement will continue to contain out-dated direction. The local codes follow the lead of national industry standards, but there is by definition a lag time, often measured in years, between the appearance of a national standard and changes in the codes. For instance, the Model Indoor Air Quality Program, adopted by the NJ PEOSH in 1997 makes no mention of fresh air ventilation rates, and requires general or exhaust ventilation only when CO2 exceeds 1000 ppm or when other contaminants exceed their PEL's. Do you see what havoc we have wrought?