Reduced Classroom Ventilation

Very nice article ("Making a Case for Reduced Classroom Ventilation" by Ernest MacFerran, PE, CIAQP, Managing Your Facilities, December 2010). I wonder what kind of reaction it will bring. I think many engineers—myself included—feel we are overventilating buildings, especially in Florida, where ambient air is so humid. But the "green" folks may feel threatened by the author's proposition. It should be interesting.
William M.R. Greenlees, PE
Anston-Greenlees Inc.
Tampa, Fla.

Great article. Thanks to the author for both his research and standing up to (ANSI/ASHRAE) Standard 62.1 (Ventilation for Acceptable Indoor Air Quality). We need more people standing up and telling ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) it is wrong.
Roger Agnew
United Engineering Group Inc.
Charlotte, N.C.

I really appreciate the author and his school district for making the effort and, of course, going to the expense of commissioning the study. It confirms my long-held gut-level feeling that we are most likely overventilating schools and other occupancies based on some pretty weak science.
Thomas R. Alexander, PE
Talex Inc., Engineers
Austin, Texas

Wonderful article. It proves what we have suspected for years: Overventilation is an unnecessary waste. Thanks to the author for doing a major part to reduce energy waste.
Jack Bruns, PE
Architectural Design Guild
St. Louis, Mo.

Great article. I e-mailed it to several people. I hope it is read by thousands of engineers and code officials across the country. There is no need to continue wasting money on bigger equipment and energy consumption.
Bill Wilson
Ossi Consulting Engineers Inc.
Tampa, Fla.

Great article. It clearly indicates the highest level of research and ability to create innovative avenues to save tax dollars and still provide an efficient level of comfort for staff and students. Hats off to the author; he is a true pioneer and innovator.
Terry L. Goins
Florida Industrial Plumbing LLC
Tampa, Fla.

Commissioning Pitfalls

I have provided indoor-air-quality- (IAQ-) testing services on several projects and was a little taken aback by the pricing in the article "Commissioning Pitfalls and How to Avoid Them" (Engineering Green Buildings, October 2010). One thousand dollars to $2,000 is a gross underestimation of the cost of this service for a building of any size. Putting that kind of pricing out to potential buyers of this service is doing them and the providers a disservice. On top of the cost of renting (if not owning) the testing equipment and labor, one has to pay a laboratory to analyze samples. Additionally, the time of "a few hours" given in the article is dependent on building size and the equipment available to rent. Some pumps run 4 hr and others 8 hr. A multifloor building could take several days to test.
Gretchen Coleman, PE, CCP, CxA
Gretchen Coleman Commissioning Group LLC
Roanoke, Va.

Author's response:
The pricing in the article is from past projects, so it is real. Nonetheless, your point is well-taken. The projects were tenant fit-outs in high-rise buildings in New York. The IAQ firm charged about $1,000 as a flat fee to cover its labor, plus $700 per test for laboratory fees. The LEED green-building certification system requires a test for each zone or 25,000 sq ft of floor area, with a test time of 4 hr per test. Therefore, for one zone of 25,000 sq ft or less, the fee would be about $1,700, including on-site labor, equipment, laboratory fees, and a brief report.

At costs of $1,000 a day for labor and $700 per test, a firm with sampling equipment could run 10 tests in a day for a 200,000-sq-ft high-rise build-out (a relatively large project) at a total cost of about $8,000. If the firm had to travel 500 miles and perform 20 tests, the fee could be $20,000, including travel and per-diem expenses.

The laboratory times in the article are for standard service, which means a two- to three-day turnaround. For next-day service, laboratory fees could jump to $1,000. Lastly, in the scenarios in the article, it is assumed the company owns the testing equipment. Renting equipment causes cost per test to rise.
Ron Wilkinson, PE, LEED AP
AKF Group LLC
New York, N.Y.

This article ("Commissioning Pitfalls and How to Avoid Them") does a good job of recapping speed bumps in the commissioning process that can be avoided with better planning and includes good suggestions for avoiding common problems. My one criticism is that it does not differentiate between tasks required by LEED and tasks required only if the LEED enhanced-commissioning credit is pursued. This will confuse readers who are less familiar with LEED and commissioning and who appear to be the target audience for the article.
Lisa
From HPAC.com

Author's response:
Unfortunately, a breakdown of the tasks for LEED fundamental commissioning and LEED enhanced commissioning was beyond the scope of the article. Fundamental commissioning is a prerequisite of the new-construction LEED programs; it must be done. Enhanced commissioning is optional and earns extra points toward certification. Of the pitfalls discussed in the article, only one, the design-review pitfall, is exclusively an enhanced-commissioning requirement. The others are more general in nature and could occur even on non-LEED projects. Refer to the LEED for New Construction v2.2 Reference Guide (available for purchase at http://bit.ly/gk82lq) for more details.
Ron Wilkinson, PE, LEED AP
AKF Group LLC
New York, N.Y.

Letters on HPAC Engineering editorial content and issues affecting the HVACR industry are welcome. Please address them to Scott Arnold, executive editor, at scott.arnold@penton.com.