[Bldg-sim] "Horses mouth" question.

[Shrestha, Som S.]

Cool roof would have high thermal emittance and low solar absorptance (high solar reflectance). So you need to modify the parameters accordingly.


Som Shrestha, PhD, BEMP
Building Scientist
Building Technologies Research and Integration Center
Oak Ridge National Laboratory
http://www.ornl.gov<http://www.ornl.gov/>
shresthass at ornl.gov<mailto:shresthass at ornl.gov>
Tel. 865-241-8772



From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of John Aulbach
Sent: Monday, October 11, 2010 3:01 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] "Horses mouth" question.

All:

Question on Cool Roof and the way to simulate them in eQuest.

My boss came to me with a cool roof and asked me to do a quick eQuest on it. I did a 25,000 sf single story office in Los Angeles, saw the roof outside emissivity was 0.9.  I changed it to 0.5 and the electric usage went UP. I change it again to 0.12 and the electric usage went up AGAIN. The HVAC is a standard single zone pacakge unit with furnace heat.

Am I seeing reality or what am I missing?

Thanks.


John R. Aulbach, PE, CEM
Senior Energy Engineer
________________________________
Partner Energy
1990 E. Grand Avenue, El Segundo, CA 90245
W: 888-826-1216, X254| D: 310-765-7295 | F: 310-817-2745
www.ptrenergy.com<http://www.ptrenergy.com/> | jaulbach at ptrenergy.com<mailto:%7C%20jaulbach at ptrenergy.com>



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