<div>Hope its not too late for me to join this discussion.</div>
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<div>If I look at 90.1 table A6.3 F = 0.73 is equal to 150mm concrete poured directly on earth that is unheated. However, if you look at the article "Underground Surfaces" by Fred Wilkenmann <a href="http://esl.tamu.edu/pub/DOE%2D2%5FOCR%5FManuals/"><strong>http://esl.tamu.edu/pub/DOE%2D2%5FOCR%5FManuals/</strong></a><strong> (DOE2 articles ground coupling models) page 10 </strong>and look at Table 1 F factors of an uninsulated and uncarpeted concrete slab on grade, F factor is 1.10.</div>
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<div>Am I misinterpreting the article? Is the 0.73 of ASHRAE table A6.3 carpeted? Because if it is then the F-factor in the table 1 will be 0.77 which is close to ASHRAE.</div>
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<div>Thanks,</div>
<div> </div>
<div>Ashok<br><br></div>
<div class="gmail_quote">On Fri, Oct 15, 2010 at 1:20 AM, Kelsey VanTassel <span dir="ltr"><<a href="mailto:KVanTassel@sustaineng.com">KVanTassel@sustaineng.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Hmm, now that I am looking at it again, I am not sure I am doing it right either. I thought the F-factor presented in the tables was already correcting for the R-value of the slab and soil, but now I'm not sure. I may be double-counting.<br>
<div class="im"><br><br>I ran into this problem too because in wizard mode, the menu of insulation configurations for slab-on-grade floors did not have the particular combination I needed. Here's what you can do in detailed edit mode instead:<br>
<br><br>1. On a space-by-space basis (or for the whole floor if it is all heated or unheated slab) calculate the R-value of the fictitious layer of insulation covering the slab:<br><br>Equivalent R-value = ((F-factor * Exposed Perimeter length)/Area of space or floor)^-1<br>
<br>(hint for determining exposed perimeter length: just add up all the widths of the exterior walls for that space. Double-click on the first exterior wall in the component tree and then press the down arrow in the menu to page through the list of just exterior walls)<br>
<br><br>2. Create a custom material of type Resistance with this R-value.<br><br><br>3. Create (or modify) the underground floor construction using the following layers (outside to inside):<br><br><br>· Material you just made<br>
<br>· Light soil damp 12 in<br><br>· 6 in HW (140lb) concrete<br><br>Kelsey Van Tassel<br>Mechanical Engineer | <a href="mailto:kvantassel@sustaineng.com">kvantassel@sustaineng.com</a><mailto:<a href="mailto:kvantassel@sustaineng.com">kvantassel@sustaineng.com</a>><br>
608.836.4488 ext. 20 | Fax: 608.836.4477<br><br>Sustainable Engineering Group<br>901 Deming Way, Suite 201<br>Madison, WI 53717<br></div><a href="http://www.sustaineng.com/" target="_blank">www.sustaineng.com</a><<a href="http://www.sustaineng.com/" target="_blank">http://www.sustaineng.com/</a>><br>
<div class="im"><br><br>From: <a href="mailto:equest-users-bounces@lists.onebuilding.org">equest-users-bounces@lists.onebuilding.org</a> [mailto:<a href="mailto:equest-users-bounces@lists.onebuilding.org">equest-users-bounces@lists.onebuilding.org</a>] On Behalf Of Will Mak<br>
Sent: Thursday, October 14, 2010 10:47 AM<br>To: <a href="mailto:equest-users@lists.onebuilding.org">equest-users@lists.onebuilding.org</a><br>Subject: Re: [Equest-users] F-Factor to U-Value<br><br></div>
<div class="im">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?<br>
<br>Thanks!<br><br>William Mak, LEED Green Associate<br>Mechanical Design Engineer<br><br>EPSTEIN<br>Architecture<br>Interiors<br>Engineering<br>Construction<br><br>600 West Fulton Street<br>Chicago, Illinois 60661-1259<br>
<br>D (312) 429-8116<br>F (312) 559-1217<br></div><a href="mailto:wmak@epsteinglobal.com">wmak@epsteinglobal.com</a><mailto:<a href="mailto:hmoats@epsteinglobal.com">hmoats@epsteinglobal.com</a>><br><a href="http://www.epsteinglobal.com/" target="_blank">www.epsteinglobal.com</a><<a href="http://www.epsteinglobal.com/" target="_blank">http://www.epsteinglobal.com/</a>><br>
<div class="im"><br>ş Epstein is a firm believer in sustainability. We ask that you please consider the environment before printing this e-mail.<br><br></div>
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