[BLDG-SIM] Loads not met interpretation in ASHRAE 90.1-2004

Xiaobing Liu XLiu at climatemaster.com
Tue Jul 10 08:30:39 PDT 2007


All:

Regarding the Unmet load, is it for sensible load only or total load (sensible and latent)?

Xiaobing

-----Original Message-----
From: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com]On Behalf Of Perron,
Brett
Sent: Tuesday, July 10, 2007 9:47 AM
To: BLDG-SIM at gard.com
Subject: [BLDG-SIM] Loads not met interpretation in ASHRAE 90.1-2004


John,
The few LEED projects I've modeled for (3), we've used unmet load for
hours for the whole building.  I like to use the Summary Tab under the
Air-Side HVAC screen to view details about my systems including unmet
load hours.  The only thing is that it's only available for the baseline
design and can't compare with any parametric runs.
Hope this helps, 
Brett

-----Original Message-----
From: BLDG-SIM at gard.com [mailto:BLDG-SIM at gard.com] On Behalf Of Rohini
Brahme
Sent: Tuesday, July 10, 2007 10:12 AM
To: BLDG-SIM at gard.com
Subject: [BLDG-SIM] Loads not met interpretation in ASHRAE 90.1-2004

I usually look through the zone report (SS-H? - the one which shows the
undercooled or underheated hours for each zone) to see if any zone has
unreasonably high numbers. Fixing these zones usually gets me a very low
number for unmet hours for the total of all zones. I would be curious to
see what others have to suggest. In your case, going through 76 zones
would be quite tedious.
- Rohini
 
All:
 
ASHRAE 90.1-2004 has design criteria for Equipment capacities on Page
176 of the Standard (G3.1.2.2). It talks about Unmet load hours on the
proposed design AND the baseline design not exceeding 300 hrs (of 8,760
Hrs), and the delta between base and proposed not differing more than 50
hours.
 
Is this WHOLE BUILDING, or BY ZONE? I have 76 zones in my building, and
to play the Unmet loads game between these two models is harder than
trying to hold water in my hands.
 
Any thoughts, interpretations, or suggestions?
 
John R. Aulbach, PE, CEM
Project Manager
Nexant, Inc.
100 North Barranca, Suite 820
West Covina, CA 91791 USA
Phone: 626-430-9054
Fax: 626-430-9060
email: jaulbach at nexant.com
 
 
 


==================
You received this e-mail because you are subscribed to the
BLDG-SIM at GARD.COM mailing list.  To unsubscribe from this mailing list
send a blank message to BLDG-SIM-UNSUBSCRIBE at GARD.COM

==================
You received this e-mail because you are subscribed to the
BLDG-SIM at GARD.COM mailing list.  To unsubscribe from this mailing list
send a blank message to BLDG-SIM-UNSUBSCRIBE at GARD.COM


==================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM


===========================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM



More information about the Bldg-sim mailing list