Floor Slab F-factor

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I'm a little tardy joining this thread, but the original write-up was
from the Spring 1998 edition of the "Building Energy Simulation"
newsletter. I am hoping someone can confirm that this is still the
correct method for the latest versions of eQuest and DOE2.2 to solve an
inter-office debate. Thanks!


Jeremy Poling's picture
Joined: 2011-09-30
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What's the point of contention you're debating?

I would begin with creating a eQuest wizard model simulation that is
representative of the slab-on-grade example(s) given in the article.


Jonathan Smith's picture
Joined: 2011-09-30
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The inter-office debate is more on advising our architect on options for
slab insulation using the energy benefits of one option compared to
another. The project having the debate is a large area low-height
building with some spaces similar to a warehouse, so from an envelope
perspective the critical envelope gain/loss surfaces are the Roof and
the Slab.

We arrived at this question for eQuest since the other model used in
house is Trace and Trace uses F-Factor directly for slab-on-grade. For
eQuest, since the guidance on converting F-Factor to U-Factor for use in
eQuest was written in 1998 and was based on DOE2.1E, does eQuest 3.64
still use the same methodology? The question also goes back to a
comment much earlier in the archives on this being an area of eQuest
that should be added in a future revision of eQuest.

Thanks for the help!


Jeremy Poling's picture
Joined: 2011-09-30
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Try this site.
The 2 programs I would suggest are the Hot2000 and Base calc. Hot2000
is residential but has a fairly detailed section on basements and slab
on grade. It is a DOE 1 or 2 engine, and does convert your input into
an F factor for analysis. There are building size limits but you should
be able to work around that by scaling. I have never used Base calc,
but it is foundation specific, it might be just what you are looking for.
EE4 was what I was using before I found eQuest, another DOE engine
without the nice eQuest front end. This group is the one working on the
metric version of eQuest. There are other good programs here for
daylighting, skylights and ground source well fields.
Bruce Easterbrook P.Eng.

Bruce Easterbrook's picture
Joined: 2011-09-30
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