[Equest-users] F-Factor to U-Value

[Nick Caton]

F-factors can't be entered directly, but are still pretty easy to handle in eQuest.

 

Open your copy of 90.1, and add a tab to Table A6.3, and read preceding section A6.

 

90.1 is explicit in what physically constitutes a floor slab with a given F-factor.  Typically, I need an unheated slab with F-0.73.  From this table and accompanying text I know that means simply to define a 6in. thick slab on grade with zero insulation while in the wizards.  eQuest does the rest.

 

I generally utilize the default library material properties (mass/conductivity) built into eQuest.  Those properties came under fire once from a nitpicky reviewer for being slightly different from Appendix A's final tables (see archives), but I learned after-the-fact that the material properties listed in 90.1 are derived from DOE2's libraries, so it was a moot issue.

 

~Nick

 

 

 

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From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Will Mak
Sent: Thursday, October 14, 2010 10:47 AM
To: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] F-Factor to U-Value

 

eQuest requires an input of a U-Value when modeling a slab on grab layer. Typically, you enter a F-Factor to account for the loss per perimeter length. I did some research but could not find any solid conclusions on what is suppose to be done to convert the F-Factor to a U-value or configure eQuest to correctly model this. Any suggestions?

 

Thanks!

 

William Mak, LEED Green Associate
Mechanical Design Engineer

EPSTEIN
Architecture
Interiors
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Construction

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Chicago, Illinois 60661-1259

D (312) 429-8116
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