Wednesday, April 27, 2011

Engineering Specification Observations

I spent a few days in Albuquerque last week, doing an ASHRAE lunch and calling on mechanical engineers. I came away with some general observations about the market there, and on the current state-of-the-art in specifications.

1) New Mexico is apparently very dependent on government work, with several military bases and a couple Federal research laboratories keeping business at least flat. The state of Federal specification/requirements is in some flux. A couple years ago, it seems UFAD was the “advanced technology”, and today it is Chilled Beams. So far, most Chilled Beam projects we see are owner driven.

2) The message on delivering hot air from overhead is still a mixed one. Some are still surprised that if one delivers air more than 15F above room temperature, one must compensate with increased outdoor to remain compliant with 62.1, which is IMC code, and likely UMC code as well. It is certainly the “Acceptable Standard of Care”. Nonetheless, our reps still see lots of VAV box schedules with design discharge temperatures well over 100F. I contend that ASHRAE Standard 55 is unlikely to be met with high discharge temperatures. Some day….

3) Acoustics is still an issue. Many are aware that the ADA Classroom recommendation of 26NC (35dBA) is being proposed for LEED 2012. What they don’t know is that the ADA is considering upgrading that to a requirement, not a recommendation. Unfortunately, not all understand that duct lining will certainly be required, and there are still a few folks who unfortunately think that glass fibers are inherently dangerous, a myth which has been disproven over and over. Glass fiber is still the safest duct lining material available, and restrictions on its use should be removed. There was a noisy diffuser in an engineer’s office, and when I asked how loud they thought it was (I guessed 40NC), at least two in the room whipped out their iPhones and told me it was 50 dBA on their free download Real Time Sound Analyzer apps. (41NC). I was close.

Authored by: Dan Int-Hout, Chief Engineer Krueger