[BLDG-SIM] ASHRAE 90.1-2004 App. G, Hospital Baseline

[Taylor, Russell D UTRC]

Dana
 
I haven't simulated any hospitals under Appendix G, but I have done a
number of pharmaceutical and bio-research labs, which had similar specs
and requirements. 
 
My assumption is that the project intends to seek LEED certification
under LEED-NC 2.2 since you are doing an Appendix G baseline.
 
I also assume that the CUP currently exists and its capacity will not be
expanded to meet the demands of the addition, therefore you will treat
the chilled and hot water from the CUP as purchased cooling and heating
in the proposed design consistent with G3.1.1.1 (this section only
mentions purchased heat, but I think it is reasonable to apply the same
approach to campus chilled water).
 
I would classify the building type as Nonresidential and 3 Floors or
Less & < 75,000 sf, which would require System 3 to be used. Even if you
consider the addition to be part of the larger building, this approach
is still consistent with Section G3.1.1 Exception (a).  
 
I'm not sure why you don't consider this to be a fair comparison since
clearly there is a design decision to be made about connecting the
addition to the existing CUP versus independent cooling and heating
systems.
 
Russ Taylor

________________________________________________________________________
_______ 

Russell D Taylor, Ph.D. 
UTRC | 411 Silver Lane, MS 129-85 | East Hartford, CT 06108 | Ph: (860)
610-7485 
________________________________________________________________________
_______ 


________________________________

From: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] On Behalf Of Dana
Troy
Sent: Monday, July 23, 2007 1:25 PM
To: BLDG-SIM at gard.com
Subject: [BLDG-SIM] ASHRAE 90.1-2004 App. G, Hospital Baseline


Hello all,
 
I am currently working on the ASHRAE 90.1-2004, Appendix G baseline
model of a hospital in Oregon. The part of the building being analyzed
is a 40,000 sf, 3 story addition to an already existing building of
approximately 90,000 sf. I am having some issues determining what to use
for the baseline HVAC system. Here are some key details of the current
as-designed building:

*	Reheat fan system 
*	Constant volume, 60,000 cfm 
*	100% outside air 
*	Draws heat from two boilers and two chiller in a central utility
plant that also serves the rest of the building

These design parameters lead to some confusion when selecting the HVAC
baseline systems. For example:

*	Since the addition is served by a system that serves the entire
building, should building be modeled as an ~130,000 sf building? This
would make it System 5 under Table G3.1.1A. Problems with this are that
it calls it out to be a PVAV w/ reheat, which is not a legitimate
comparison. If the baseline is supposed to be PVAV, the OSA requirements
need to be the same anyways (G3.1.2.5), therefore effectively making it
a constant volume system. 
*	Should the sf be taken relative to only the addition (40,000
sf)? This is also not a fair comparison between the two systems because
the addition draws heating and cooling from a system designed for a much
larger square footage. 

I guess my main questions are if anyone has dealt with large, constant
volume, 100% OSA systems and their baseline HVAC systems and if anyone
has modeled additions that are served by a larger CUP.
 
Thanks for any help in advance.
 

Dana Troy, EIT
Energy Analyst 

 <http://www.glumac.com/>  
________________________________

320 SW Washington, Suite 200
Portland, OR 97204-2640
T.  503.227.5280  F. 503.274.7674
D. 503.345.6286

Thinking. Inside the building.
www.glumac.com <http://www.glumac.com/>  

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