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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>In general, I think that the article referenced below is a great start to UFAD modeling systems in eQuest. However, since the article was written, much more research has been done (mainly by the Center for the Built Environment-UC Berkeley) in the area of UFAD modeling. This article (EDR link) suggests that displacement (TDV) and UFAD systems can be modeled the same. While some of the dynamics are the same, this is not the case. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>What the EDR article does not expand on is the issue of supply plenum temperature decay and return air plenum temperature decrease that occurs with UFAD systems. If you simply use the EDR factors, what you will find is that return air temperature is higher than what actually occurs, and plenum supply air is lower than reality as well. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>For those of us that have design/installation experience with UFAD systems, return air temperatures are not in the 78-80 degree range, but closer to 75-77 degrees (assuming a space temp of 74/75 degrees). Why? Consider in a multi-story building a section, heat from the return plenum will be lost both to the floor above due and also the floor below by means of radiation. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>Supply plenum heat gain is a much harder thing to quantify, since you have the issues of return air gain, as described above, but is much more complex. Supply air plenum heat gain is also a function of airflow, inlet supply temperature, and how the supply air gets injected to the plenum. More inlets and inlets closer to the exterior can minimize plenum heat gain. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>Also, be very conscious on the type of eQuest system used versus the type of UFAD system designed. In general, a PIU system for a UFAD system that has swirl diffusers on the interior and fan powered boxes on the perimeter is acceptable (you just have to understand how the perimeter box operates). All UFAD systems are unique, so be sure to understand the design carefully.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>Here is what I would recommend:<o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>-Do not just model the system as the EDR link describes. If you do, you will probably over estimate UFAD savings. <o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>-Read through the ASHRAE article from October 2007 titled "Cooling Airflow Design Calculations for UFAD"<o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>-Read through all of CBE's free online resources. They have information on many UFAD topics, including airflow calcs, energy modeling, comfort, and more. <a href="http://www.cbe.berkeley.edu/research/research_hvac.htm"><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>http://www.cbe.berkeley.edu/research/research_hvac.htm</span></a> <o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>-Also remember that in the latest eQuest update, you can input user defined Radiant/Convective splits. This is a huge development for UFAD systems.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>Andy<o:p></o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>PS: If you’re just looking for a quick simulation of UFAD, without all the headache of trying to manipulate eQuest, I’d try another simulation engine. There are some out there that have routines written for UFAD. EnergyPlus is probably the best, since they base things on CBE research.<o:p></o:p></span></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>-----Original Message-----<br>From: equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] On Behalf Of Nick Caton<br>Sent: Tuesday, July 26, 2011 4:07 PM<br>To: Hall, Brendan; Kazim Mirza; equest-users@lists.onebuilding.org<br>Subject: Re: [Equest-users] Underfloor Modelling and Error Message.</p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>There's a large chapter in the EDR guidelines that pretty much details an overall "how-to" for UFAD in eQUEST... recommend downloading the PDF linked at the bottom and perusing!<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><a href="http://www.energydesignresources.com/resources/publications/design-guidelines/design-guidelines-hvac-simulation-guidelines.aspx"><span style='color:windowtext;text-decoration:none'>http://www.energydesignresources.com/resources/publications/design-guidelines/design-guidelines-hvac-simulation-guidelines.aspx</span></a><o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>IIRC - this is written in a fashion that does a good job of outlining the limitations of UFAD in eQUEST, and provides guidelines for DOE2 system selection by pointing out behaviors that might be desirable to include in the simulation.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>~Nick<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>NICK CATON, P.E.<o:p></o:p></p><p class=MsoPlainText>SENIOR ENGINEER<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Smith & Boucher Engineers<o:p></o:p></p><p class=MsoPlainText>25501 west valley parkway, suite 200<o:p></o:p></p><p class=MsoPlainText>olathe, ks 66061<o:p></o:p></p><p class=MsoPlainText>direct 913.344.0036<o:p></o:p></p><p class=MsoPlainText>fax 913.345.0617<o:p></o:p></p><p class=MsoPlainText><a href="http://www.smithboucher.com"><span style='color:windowtext;text-decoration:none'>www.smithboucher.com</span></a> <o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>-----Original Message-----<o:p></o:p></p><p class=MsoPlainText>From: equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] On Behalf Of Hall, Brendan<o:p></o:p></p><p class=MsoPlainText>Sent: Tuesday, July 26, 2011 3:44 PM<o:p></o:p></p><p class=MsoPlainText>To: Kazim Mirza; equest-users@lists.onebuilding.org<o:p></o:p></p><p class=MsoPlainText>Subject: Re: [Equest-users] Underfloor Modelling and Error Message.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>A PIU system is fine, especially if you are using fan powered boxes to serve your perimeter. The more important part of trying to approximate an underfloor system is correctly appropriating the loads between the conditioned and unconditioned zones. <o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>As for the error, what is your supply temperature? It seems like the error would be related to a small dT between the room setpoint and the supply air temperature, which would require calling for a large volume of air to satisfy the loads in the conditioned zone. You might also try having different set points for your heating and cooling, there should be at least a 5F dead band per ASHRAE 90.1. 6.4.3.1.2. Hope that helps.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Brendan Hall, M.Sc., LEED AP BD+C<o:p></o:p></p><p class=MsoPlainText>Mechanical Engineer<o:p></o:p></p><p class=MsoPlainText> <o:p></o:p></p><p class=MsoPlainText>karpinski<o:p></o:p></p><p class=MsoPlainText>ENGINEERING<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>3135 Euclid Avenue<o:p></o:p></p><p class=MsoPlainText>Cleveland, OH 44115<o:p></o:p></p><p class=MsoPlainText>P 216.391.3700<o:p></o:p></p><p class=MsoPlainText>F 216.391.0108<o:p></o:p></p><p class=MsoPlainText>E <a href="mailto:bhall@karpinskieng.com"><span style='color:windowtext;text-decoration:none'>bhall@karpinskieng.com</span></a><o:p></o:p></p><p class=MsoPlainText>W <a href="http://www.karpinskieng.com"><span style='color:windowtext;text-decoration:none'>www.karpinskieng.com</span></a><o:p></o:p></p><p class=MsoPlainText> <o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>-----Original Message-----<o:p></o:p></p><p class=MsoPlainText>From: equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] On Behalf Of Kazim Mirza<o:p></o:p></p><p class=MsoPlainText>Sent: Tuesday, July 26, 2011 4:18 PM<o:p></o:p></p><p class=MsoPlainText>To: equest-users@lists.onebuilding.org<o:p></o:p></p><p class=MsoPlainText>Subject: [Equest-users] Underfloor Modelling and Error Message.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Hello eQuesters,<o:p></o:p></p><p class=MsoPlainText> I had two questions:<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>(1) Can underfloor modelling be done in eQUEST.? Does any body know which 'system type' to consider? I have considered a powered induction system type.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>(2) I got a error message from one of my model as follows. Can some one help me understand this error?. i have attached my print screens on the air side for this model.<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>*WARNING**********************************************************************<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Zone: EL1 North Perim Zn (G.N1) has a design cooling<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>temperature differential of only 4.0F. This<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>may result in an extremely large design airflow.<o:p></o:p></p><p class=MsoPlainText>***********************************************************************************<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Thanks,<o:p></o:p></p><p class=MsoPlainText><o:p> </o:p></p><p class=MsoPlainText>Kazim<o:p></o:p></p><p class=MsoPlainText>_______________________________________________<o:p></o:p></p><p class=MsoPlainText>Equest-users mailing list<o:p></o:p></p><p class=MsoPlainText><a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org"><span style='color:windowtext;text-decoration:none'>http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</span></a><o:p></o:p></p><p class=MsoPlainText>To unsubscribe from this mailing list send a blank message to <a href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG"><span style='color:windowtext;text-decoration:none'>EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</span></a><o:p></o:p></p><p class=MsoPlainText>_______________________________________________<o:p></o:p></p><p class=MsoPlainText>Equest-users mailing list<o:p></o:p></p><p class=MsoPlainText><a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org"><span style='color:windowtext;text-decoration:none'>http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</span></a><o:p></o:p></p><p class=MsoPlainText>To unsubscribe from this mailing list send a blank message to <a href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG"><span style='color:windowtext;text-decoration:none'>EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</span></a><o:p></o:p></p></div></body></html>