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<DIV><SPAN class=734585219-27042011><FONT face=Arial
size=2>Hi,</FONT></SPAN></DIV>
<DIV><SPAN class=734585219-27042011><FONT face=Arial size=2>I've been struggling
with this issue for a while now. What is a good way to come up with an
acceptable U-value for slab-on-grade floors based on the F-values listed in
ASHRAE Standard 90.1?</FONT></SPAN></DIV>
<DIV><SPAN class=734585219-27042011><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=734585219-27042011><FONT face=Arial size=2>A while back, I
received an Excel sheet from someone at HAP support. It's supposed to help you
arrive at a U-value, but there seems to be too much freedom to come up with a
wide range of U-values as you can change several variables. One thing in
particular I'm curious about is defining the Effective Width of Slab. The
directions on the Excel sheet say to use the distance from the exterior wall of
a given space to the opposite interior wall if you are finding a U-value for
just the space. However, it also says you can use the distance from the
perimeter to the center of the building if you are finding the U-value for the
entire building slab. Two things: (10) This is a lot of work for a
building with 200 and some spaces and doesn't seem worth the effort. (2) if the
building isn't a square, how do you define the center of the slab
(aside from using calculus)? </FONT></SPAN></DIV>
<DIV><SPAN class=734585219-27042011> </SPAN></DIV>
<DIV align=left><FONT face=Arial size=2>Sincerely,</FONT></DIV>
<DIV align=left><FONT face=Arial size=2></FONT> </DIV>
<DIV align=left><FONT face=Arial size=2>N. E. Fisher &
Associates</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Matt Scott</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>e: <U><FONT color=#0000ff><A
href="mailto:mscott@nefisher.com">mscott@nefisher.com</A></FONT></U></FONT></DIV>
<DIV align=left><FONT face=Arial size=2>p: 610-369-3190</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>f: 610-369-3194</FONT></DIV>
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