Dear folks,
APP G3.1.3.7 specifies centrifugal chillers in baseline models where
conditioned area is greater than 22,296 m2. I always take them as
water-cooled chillers by default.
Today one of my clients challenged why air-cooled centrifugal chillers can't
be modeled in the baseline. His argument is that there is not any
"water-cooled" explicitly specified in G3.1.3.7, but there are air-cooled
centrifugal chillers available in the market.
I was attemping to convince him of my understanding by searching
ASHRAE 90.1and the associated user manual. But I failed to find any
evidence. I doubted
if I was wrong.
Is there anyone in this forum who can give me an answer? And if I am still
right, how can I convince my client who is hungry for points of EA cr1?
Tons of thanks in advance.
Jessi
Greetings-
Does not APPG3.1.3.11 Address this? It states the heat of rejection for the chillers must be a cooling tower. It further describes the condenser water requirements.
Anybody else see anything?
Hope this helps.
Regards,
W. Peter Anderson, P.E
Jessi,
You are correct, all chillers modeled in the baseline building per Appendix G are water cooled. See G3.1.3.11 Heat Rejection (Systems 7 and 8), which states "The heat rejection device shall be an axial fan cooling tower with two speed fans...".
Since this issue was confusing to others as well as your client, it was clarified in the 2007 version of Appendix G, and now specifically adds "Water-Cooled" to the chiller type in the table.
Michael Rosenberg
Dear folks,
APP G3.1.3.7 specifies centrifugal chillers in baseline models where
conditioned area is greater than 22,296 m2. I always take them as
water-cooled chillers by default.
Today one of my clients challenged why air-cooled centrifugal chillers can't
be modeled in the baseline. His argument is that there is not any
"water-cooled" explicitly specified in G3.1.3.7, but there are air-cooled
centrifugal chillers available in the market.
I was attemping to convince him of my understanding by searching
ASHRAE 90.1and the associated user manual. But I failed to find any
evidence. I doubted
if I was wrong.
Is there anyone in this forum who can give me an answer? And if I am still
right, how can I convince my client who is hungry for points of EA cr1?
Tons of thanks in advance.
Jessi
I am modeling a water loop heat pump system for a California
installation and in trying to get the E-Quest Compliance part to run,
E-Quest is asking for "Heat Pump Configuration" and states that the
default is "zero". The DOE-2 documentation in Volume 5, Compliance
Analysis, states that the variable is C-HP-CONFIG and the options are:
TYPE = ALL OTHERS
0 - Single Package
1 - Split System
TYPE = PTAC
2 - Pkg Terminal Heat Pump
3 - Room HP with louvered sides
4 - Room HP w/o louvered sides
No matter what System Type I put in, the screen does not appear to
accept an entry, but it will accept a "default" from the "Required
Inputs" screen. I believe that this enters a "zero" which would be
"Single Package". It would seem to me that "Pkg Terminal Heat Pump"
would be more accurate, but I can't seem to get it to allow me to input
a "2".
I have a feeling that this is one of those "must use manual entries"
issues, but I have never done that and I am not anxious to try it.
Any advice would be appreciated.
Sincerely,
Robert Wichert