Hi all,
I have a tenant fit-out project served by water source HPs.
There is a building standard for the equipment (Building owns/maintains equipment, and regulates unit make/model used in tenant space). The building calls for the "high efficiency" model heat pumps to be used.
We are replacing nearly all of the units serving the space (roughly 15), but 4 have been recently replaced, work out for the new zoning, and the owner & tenant would like to keep them for reuse.
Do these existing systems need to meet the CPG guidelines for unit efficiency?
The "high efficiency" models from a few of years ago were great for their time, but technically do not quite meet the CPG requirements.
Do we have to replace these units to meet the LEED requirements?
Or are the requirements only for newly installed equipment?
Seems like a waste to remove good units to replace them with something that is only slightly more efficient.
Thanks,
Tony
Dylan Connelly
Mechanical EngineerIntegral Group
LEEDuser Expert
472 thumbs up
August 13, 2013 - 6:45 pm
See LEED Interpretation 10134. Only systems that are supplying 60% of the air or heating/cooling need to comply.
Tony Ricketts
Mechanical EngineerCJL Engineering
25 thumbs up
August 14, 2013 - 5:36 pm
Thanks Dylan!
This is very helpful.
One other question I'm a little uncertain about:
Since the ventilation air provided to the space is part of the base building systems, should I include that in the capacity percentages as I'm verifying the 60/40 split in new vs old equipment?
(I ask this way because in "most" projects the OA is supplied through a larger central building unit, over which a tenant has very little control. Also, estimating the prorated load of the unit could be difficult, depending on the building owner's records. In our case, the OA is provided through 5 CAV WSHPs mounted above the ceiling in the tenant space. These units "could" be replaced, if necessary, but it is not in the tenant's construction budget.)
Thanks for the help!
Tony
Dylan Connelly
Mechanical EngineerIntegral Group
LEEDuser Expert
472 thumbs up
August 16, 2013 - 1:39 pm
Tony,
The way I read the LEED interpretation the 60% rule means only single pieces of equipment that supply 60% of the space's capacity. However, it could be that if the same type of system is serving the whole space or most of the space they would need to comply as well. It's not clear.
Another good point you made is that the interpretation doesn't say anything about ventilation systems. You could assume the 60% rule there as well to be conservative.