Wednesday, July 25, 2012

Flawed Specifications


I was recently asked to review a specification provided by a consulting engineer for a project at a large university. I was appalled at what I found. I started to list the flaws in the specification, but after listing about a dozen, I gave up. The specification was so filled with inconsistencies and incredibly obsolete references that it made no sense to continue.

I wrote an article for the Construction Specifier magazine back in 2004 (which can be found at http://www.krueger-hvac.com/lit/pdf/conspecvav.pdf) where I outlined a number of items found in specifications which were impossible to meet, as they were either referencing obsolete standards, required performance which could never be obtained, or were simply self-contradictory. Nevertheless, our reps and their customers are required to meet these flawed requirements.

The specification I mentioned above was worse than any I cited back in 2004. Issues found included:

- Reference to ADC 1062-R2. This standard was superseded by -R3, -R4 and finally was discontinued when the ADC stopped certifying air distribution devices in 1084. I believe -R2 was released in about 1973. It never dealt with VAV boxes in a comprehensive manner and was replaced by ASHRAE Standard 130 and ARI-880.

- There were requirements for "medium speed", an SCR speed controller, and then required ECM motors on fan boxes. There is no “medium speed” on the required ECM motors and they do not use SCR speed controllers.

- The spec called for a specific brand of pneumatic controller and then, in the same paragraph, specified DDC controllers.

- The spec then required “snap acting” actuators, “normally open”. This is a $200 add over conventional electric actuators, and “normally open” is a pneumatic control sequence.

- The acoustical portion of the spec was completely ineffective. It listed octave band sound requirements with no description of the set up which was required to measure these values, and the values themselves were unlikely to be achieved under any conditions. There was no mention of AHRI 885, the acoustical calculation specification which has been in place since 1989 and is required by manufacturer’s to use when presenting NC values in catalogs.

The challenge now is for the rep to call on the engineer and somehow point out his flawed requirements without insulting either their competence or intelligence. I have attempted to do so in the past with a large consulting engineer who continues to flatly specify a device whose published performance data is based on 1980 instrumentation and cannot be repeated under today’s Standards (ASHRAE Standard 70) and greatly underreport the device’s throws. When challenged, I was told that “fixing the specification now would, in effect, be an admission that our spec was flawed for the past 30 years”. (It was.)

At some point, consulting engineers need to review their “standard” specs for flaws, inconsistencies, and obsolete references. Meanwhile, of course, everyone will continue to bid their work, knowing that the specs  cannot be enforced.

Authored by: Dan Int-Hout, Chief Engineer Krueger