[Bldg-sim] Freezer and cold storage in the building

Jeff Haberl jeffhaberl at tees.tamus.edu
Fri Feb 6 20:39:36 PST 2009


FYI:
 
This can be done, but it requires "tricking" the simulation. 
 
First, DOE-2 has a lower limit on zone temperatures, which is hard to override. We did a paper in 1985 (ASHRAE Transactions) where we simulated an ice rink and a swimming pool with DOE-2 at a rec center. To trick DOE-2 into calculating the heat loss from the ice rink we bumped up the UA to compensate for the lower delta T. 
 
Another way to do this is to drop a (-) SOURCE into a zone...that has the equivalent cooling load as the freezer and/or cooler. However, you'd
need to know what the cooling load is on the unit...with most of the freezers I've seen the biggest load is in the cool down of product, and/or the 
infiltration into/out of the unit as employees go in/out all day long. Hard to tell what this would be. 
 
Finally, if the condenser to the unit is inside the restaurant, then you'll have a heat gain to the space equal to the condenser load plus the heat off the compressor.
 
I'm sure you'll find some other, more recent papers on modeling restaurants. For example, there were several excellent Seminar presentations 
at the Chicago meeting. Not exactly modeling, but very good presentations on reducing energy use in restaurants.
 
Good luck.
 
Jeff
 
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Jeff S. Haberl, Ph.D., P.E.............................jhaberl at esl.tamu.edu
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________________________________

From: bldg-sim-bounces at lists.onebuilding.org on behalf of Maudud Quazi
Sent: Fri 2/6/2009 10:12 AM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Freezer and cold storage in the building


I am modelling a rastaurant that has a freezer and a cooler substantially large.  Can they effect the building heat and cooling load.  If so, what do I zone them as and how do I incorporate them in the HVAC system? Thank you. 



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