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Oh Contrair.
<p> I ran load calcs for a 100,000 square foot single story big box
store in the Burlington, VT area last year to determine what if any benefits
would result from changing the flat membrane roof color from dark to light.
Occupancy was typical urban sprawl well-known national retailers.
<p>Peak air conditioning roof heat gain was reduced by 50%.
<p>Roof was insulated to about R-22, plenum return, packaged DX rooftops.
Ran the numbers using Carrier HAP. Annual AC energy savings came
in at about 3%. Software did show a *slight* heating season penalty,
but that was because the software did not account for the usual snow cover
on a Vermont roof in winter. There was a worthwhile installed tonnage reduction
also.
<br>
<dl>
<dd>
<font size=-1>Thomas E. Anderson</font></dd>
<dd>
<font size=-1>President</font></dd>
<dd>
<font size=-1>Cx Associates, Ltd.</font></dd>
<dd>
<font size=-1>Building Commissioning Specialists</font></dd>
<dd>
<i><font size=-1><a href="http://www.cx-assoc.com">http://www.cx-assoc.com</a></font></i></dd>
<dd>
<i><font size=-1>933 Road 101</font></i></dd>
<dd>
<i><font size=-1>Jeffersonville, Vermont 05464 USA</font></i></dd>
<dd>
<i><font size=-1>hvac@cx-assoc.com</font></i></dd>
<dd>
<i><font size=-1>Tel: 802-644-5616 Fax: 802-644-6797</font></i></dd>
</dl>
Marcus Sheffer wrote:
<blockquote TYPE=CITE> Whenever we have modeled this in the Northeast
we also have seen negligible savings using PowerDOE and others.
<p>We have come to the conclusion that the savings depend upon the amount
of roof insulation and type of building. If we enter minimal insulation
the effect of a white roof is larger especially in a cooling dominated
building, high internal loads, etc.
<p>If you are installing even moderate amounts of insulation (R15 or more)
then the effect of a white roof in the Northeast is virtually nil for most
any building type.
<p>Now when it comes to the urban heat island effect it can have a tremendously
positive impact . . . but that is another issue.
<br>
<p>At 01:55 PM 10/07/2002 -0400, you wrote:
<blockquote type=cite class=cite cite><font face="arial"><font size=-1>Has
anyone had any success modeling cool roofing options (i.e. reflective or
light colored surfaces) in PowerDOE? So far, I have seen negligible
results from the adjustment of roof construction absorptance values (emissivity
is also known to play a role, but there is no input for this in PowerDOE).
I have seen data showing cooling energy savings from 0.06 to 0.54 kWh/sqft/yr,
depending on building type. I am getting only a very small fraction
of this. Data collected in the study was from facilities in the southern
and western US, and I work primarily on buildings in the Northeast.</font></font>
<p><font face="arial"><font size=-1>My questions:</font></font>
<br><font face="arial"><font size=-1>How well can I expect PowerDOE to
simulate this? Is there a better way to simulate cool roofing?
Is the sun simply too low in the sky in New England to yield substantial
savings?</font></font>
<p><font face="arial"><font size=-1>Your thoughts are appreciated.</font></font>
<p><font face="arial"><font size=-1>Wade McLaughlin</font></font>
<br><font face="arial"><font size=-1>DMI</font></font></blockquote>
<x-sigsep>
<p></x-sigsep><font face="Abadi MT Condensed Light"><font color="#008000"><font size=+1>Marcus
B. Sheffer
energy & environmental consulting</font></font></font>
<br><font face="Abadi MT Condensed Light"><font color="#008000"><font size=+1>Energy
Opportunities
717-292-2636</font></font></font>
<br><font face="Abadi MT Condensed Light"><font color="#008000"><font size=+1>1200
E Camping Area Road
Fax: 717-292-0585</font></font></font>
<br><font face="Abadi MT Condensed Light"><font color="#008000"><font size=+1>Wellsville,
PA USA 17365-9783 sheffer@sevengroup.com</font></font></font>
<br><font face="Abadi MT Condensed Light"><font color="#008000"><font size=+1>a
Seven Group member company <u><a href="http://www.sevengroup.com/" eudora="autourl">www.sevengroup.com</a></u></font></font></font></blockquote>
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