Dear All,
Our current project is an existing building renovation, where boiler and chiller in the 2 pipe fan coil system are retained, but the fan coil units are replaced with new ones. The mechanical contractor informs us that it is cost prohibitive to implement an Optimum Start functionality as required by ASHRAE 90.1-2007. How are we supposed to approach this in your opinion? Can we assume that this heating / cooling system is an existing system and therefore does not have to comply with the prescriptive requirements of ASHRAE 90.1-2007?
Thanks,
Christopher Schaffner
CEO & FounderThe Green Engineer
LEEDuser Expert
963 thumbs up
May 28, 2010 - 10:38 am
First, I'd push back a bit. If you have a system over 10,000 CFM, implementing optimal start is usually a very quick payback item. And if you are less than 10,000 CFM, the requirement (6.4.3.3.3) does not apply.
Now, having said that, it is my understanding that the mandatory measures generally do not apply to existing equipment.
Section 2 of the Standard ("Scope") indicates that the standard only applies to:
"1. new buildings and their systems
2. new portions of buildings and their systems
3. new systems and equipment in existing buildings. "
However, if you are doing an energy model, the baseline building model needs to include all mandatory provisions, including the optimal start.
My advice - pay the $2 - put in the optimal start controls,