Writing A Verifiable Controls Specification
I often have people (both building operations professionals and consultants) ask me questions relating to how to put together a controls specification for which it will be relatively easy, after installation, to verify that everything was installed and commissioned properly. Controls specifications have changed over the years. At this point, many controls specs that I see pretty much just consist of a points list and sequence of operation. If the sequence is well written, the controls contractor will have a good idea of what is expected. But how do you write a controls spec that ensures that you can follow up after the fact and be able to easily spot check and verify that the design has been implemented? The key is in the human interface requirements that you specify.
One of the things I like most about modern controls is the video game-like interface. There is really no reason to settle for less than a full floor plan, with suite boundaries noted, every temperature zone color coded, thermostat location marked and an info box in each zone. The info box will typically show at least set point and actual temperature. The zone may have a red or other highlight color if the zone is more than 3 F (or some other amount; it should be adjustable) out of set point. If you click on the box, you get a VAV box graphic (assuming that it is a conventional VAV reheat system; if a different system, the details would obviously be different). The graphic provides a variety of pertinent info, including cfm, leaving air temperature, minimum cooling cfm, heating cfm, hot water valve position, etc.
We often focus on this sort of display information from a facility manager’s operations perspective, and that is fine. But maybe it also makes sense to also think in terms of how the control system’s human interface can help you with anything ranging from a spot check to a full commissioning effort.
For a more detailed discussion, go to my monthly ASHRAE So Cal chapter newsletter (the Sol Air) column from November 2014. The linky: http://www.ashrae-socal.org/pdf/SolAir_November_2014_Final.pdf