[Bldg-sim] FW: eQUEST - City Chilled Water Loop and ASHRAE Appendix G

Keith Swartz kswartz at ecw.org
Thu Jul 17 13:29:03 PDT 2008


Michael,

Regarding modeling "extra" systems for conditioned spaces, the key is
"conditioned" spaces. See the definition of "conditioned space" in the
standard. If a space has no heating or cooling, it is not a conditioned
space. The User's Manual for ASHRAE 90.1-2004 clarifies that "This
requirement only applies to conditioned spaces in the building.
Semiheated spaces would only have a heating system; unconditioned spaces
would have neither heating nor cooling systems." (p. G-21) See the
definition for "semiheated space" too. I believe the intent here is to
add a cooling system to spaces that only have a heating system and add a
heating system to spaces that only have a cooling system.

If the model is for LEED, the LEED-NC v2.2 Reference Guide clarifies it.
"For areas of the project without heating or cooling systems (such as
parking garages), there is no need to model heating or cooling systems
in either the Proposed or Baseline Designs." (p. 181)

I don't know of any restrictions on the thermostat settings, so you
might be able to just make the thermostat setting of the fictitious
system pretty extreme so that the system rarely (or never) comes on.
This would satisfy the requirement to have a system, but keep your
energy consumption numbers more realistic.

Sincerely,

Keith Swartz, PE, LEED(r) AP
Energy Engineer / Senior Project Manager
Energy Center of Wisconsin
455 Science Drive, Suite 200
Madison, WI 53711

Phone: 608-238-8276 ext. 123, Fax: 608-238-0523
<http://www.ecw.org> www.ecw.org  The Energy Center of Wisconsin is a
nonprofit organization that seeks solutions to energy challenges.

________________________________

From: Michael Bejrowski [mailto:MichaelB at auseea.com] 
Sent: Wednesday, July 16, 2008 2:40 PM
To: Bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] eQUEST - City Chilled Water Loop and ASHRAE Appendix
G

 

How do you model a building that is attached to a city chilled water
loop?

 

and

 

Have any of you had experience with ASHRAE 90.1 Append. G, Table G3.1,
1c where it says "All conditioned spaces in the proposed design shall be
simulated as being both heated and cooled even if no heating or cooling
system is to be installed,..."?

 

We modeled a building that had heated vehicle maintenance bays, so by
the ASHRAE standard it would seem that we could not model it that way,
but would have to model it as being heated AND cooled.

 

Any ideas or experience would be greatly appreciated.

 

 

Thanks,

 

Michael Bejrowski

Mechanical EIT

Austin, TX

 

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