Hello, yes it's another Appendix G Baseline question.
Typical Residential Tower system with water-cooled heat pumps for the
dwelling units. Tower Loop is closed system with a heat injection boiler
for the winters (northeast climate). Heat injection boiler is natural
gas fired.
Is the Baseline "Electric and Other"? or "Fossil/Electric Hybrid"
I have seen many postings about WSHP being modeled as "all electric"
heating, but I am getting push back on this in the office because of the
heat injection component. Any CIRs on this one? System is obviously very
common.
Thanks
Alan Jackson, LEED AP
Hi Jason,
I will choose Fossil/Elec. Hybrid and PTAC for your design.
Regards,
Cheney
Cheney
Hey, thanks for the response. I agree, I think hybrid is the way to go
in this scenario.
One other issue I came across, since I not as familiar modeling
residential buildings, is the way that egress areas are treated. ASHRAE
list residential spaces as only including "guest rooms, living quarters,
private living space and sleeping quarters."
Does this mean the residential corridors and stairs need to be System 7,
and not PTAC, since the building is greater than 5 stories?
Thanks again,
Alan Jackson, LEED AP
So far as system type goes, consider that your building is first either
Residential or Nonresidential, and your building type determines your
baseline system.
The only reason you'd have both building types (and thus 2 baseline
system types) is if you have non-predominant conditions per exceptions
to G3.1.1.
If you've got >20,000SF of egress/back-of-house spaces, you might pursue
a second baseline system type declaring non-predominant conditions, but
for simplicity I'd be inclined to lump it all under one baseline type as
part of a residential building, unless told otherwise.
NICK CATON, E.I.T.
Nick,
Yes, it is well below 20,000 ft2 so I believe you are correct. Thanks
for the help. I will proceed under the residential building system type.
Alan Jackson, LEED AP