[Bldg-sim] FW: Negative cooling Load in LS-B report (Space Peak LoadComponent

[Keith Swartz]

Virdi,

I suspect that solar gains have something to do with your peak cooling
occurring in December, assuming that the internal loads are pretty
consistent throughout the year. Perhaps there is a shading device that
allows sunshine to enter through the window in December and not the rest
of the year.

The negative cooling load means that some of the heat within the room is
being conducted through the window to the outside. It makes sense in
your case since the outside temperature is cooler than the inside
temperature. Since some of the heat is escaping to the outside through
the window, less heat has to be removed through the HVAC system.

We have to wonder why heat is not also being conducted through the wall
and roof (if any). This is probably a very transient situation,
especially if the sun is the culprit. Perhaps the thermal mass of the
wall and roof prevents it from responding as quickly as the window.


Sincerely,

 

Keith Swartz, PE, LEED(r) AP

 

Energy Center of Wisconsin

455 Science Drive

Suite 200

Madison, WI 53711

 

Phone: 608-238-8276 ext. 123

Fax:     608-238-0523

www.ecw.org

The Energy Center of Wisconsin is an independent, nonprofit organization
that seeks solutions to energy challenges.


-----Original Message-----
From: Virdi Permana [mailto:Virdi.Permana at smithgroup.com] 
Sent: Sunday, February 03, 2008 8:33 PM
To: bldg-sim at lists.onebuilding.org
Cc: Jeff Hirsch
Subject: [Bldg-sim] Negative cooling Load in LS-B report (Space Peak
LoadComponent

Hello All,
1. What is the theory behind negative cooling load in LS-B report?
I have LSB report with sensible cooling load that has "window glass +
Frm cond" with negative value while the rest of the envelope component
are positive?
2. And why eQUESt selects Dec 3 data that has 68 F dry bulb temperature
to calculate peak cooling load while the zone temperature is set at 82F?
Thank you for any response that can be shared.
 
Sincerely,
 
Virdi Permana
SmithGroup

________________________________

From: bldg-sim-bounces at lists.onebuilding.org on behalf of Virdi Permana
Sent: Sat 2/2/2008 6:21 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Envelope Load



Hello All

I am currently trying to determine the ANNUAL heating and cooling load
for each component (wall, roof, window) of the building using eQUEST.
I am able to find the peak load using report LS-B.
However as I observe report LS-E to get the annual load per component,
It's difficult to determine the heating or cooling load from it as the
data that is presented in that report is the summation over a month
period. (Hence, you could find "heat loss" data in the "sensible
cooling" row).
Is there way to derive the annual heat loss (heating) and heat gain
(cooling) per building component using eQUEST?
Any information you could share is greatly appreciated.
Sincerely,

Virdi Permana
SmithGroup
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