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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Nick,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The original post as well as follow ups from Paul and myself discuss loses that occur in supply and return ducts, not limiting the discussion to return ducts nor limiting it to plenum loses, for that matter.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Equest has inputs for duct loses, in several different formats/locations. In my experience, it has been difficult to accurately model these loses and obtain logical results.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I believe Mike’s point was “if the air in the duct is the same temp as the air the duct is passing through, the effect is negligible”. I certainly agree with that, and the classic example of that scenario is a return duct (carrying room temperature air) passing through conditioned space or plenums (assuming the temp of the plenum is near the temp of the space).<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>From a practical standpoint, unless you are working on an existing building with outdated construction standards, or trying to model a specific energy conservation measure that analyzes the impact of duct insulation (or potentially changing supply air temps), there are few compelling reasons to account for these loses (from an energy use standpoint). <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>On the other hand, if you are trying to run load calcs for equipment sizing, you may want to account for them. Again, equest has inputs under “duct loses” to do so. It sort of sounds like this is what the original poster is asking for. (original poster: try to calculate the ducts UA value and use that).<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Nick Caton [mailto:ncaton@smithboucher.com] <br><b>Sent:</b> Wednesday, March 30, 2011 5:09 PM<br><b>To:</b> John Bixler; Paul Diglio; equest-users@lists.onebuilding.org<br><b>Subject:</b> RE: [Equest-users] question about inefficiency of duct<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Paul/John,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks very much for the clarifications! I’m learning a thing or two, but I suspect my choice of words might be getting in the way of what I was trying to convey… <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Please consider and affirm or correct this statement: <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><u><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>If there is rarely a case where return duct plenum losses/gains are negligible, then it follows all energy models should explicitly account for these losses/gains to those spaces.<o:p></o:p></span></u></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>A specific follow-through would be: If an eQuest model does not model conductive heat gains/losses in the return air path, does that make the eQuest model invalid? <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Trying to pull this discussion back into daily practice with eQuest… I am still fuzzy on exactly how and to what extent eQuest/DOE2 does model such internal supply and return duct losses/gains (outside of light load fractions)… Can anyone in the know clarify this query?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>~Nick<o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><img width=119 height=37 id="_x0000_i1028" src="cid:image001.jpg@01CBEEFE.3E0EEAE0" alt="cid:489575314@22072009-0ABB"></span><b><span style='font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2D4D5E'><o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2D4D5E'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2D4D5E'>NICK CATON, E.I.T.</span></b><b><span style='font-family:"Stylus BT","sans-serif";color:#2D4D5E'><o:p></o:p></span></b></p><p class=MsoNormal><span style='font-size:7.5pt;font-family:"Calibri","sans-serif";color:#CC9900'>PROJECT ENGINEER<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E'>Smith & Boucher Engineers</span><span style='font-size:7.5pt;color:#CC9900'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E'>25501 west valley parkway<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E'>olathe ks 66061<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E'>direct 913 344.0036<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2D4D5E'>fax 913 345.0617<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><a href="www.smithboucher.com" title="blocked::www.smithboucher.com"><span style='font-size:10.0pt'>www.smithboucher.com</span></a></span><u><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:blue'> </span></u><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>John Bixler<br><b>Sent:</b> Wednesday, March 30, 2011 9:15 AM<br><b>To:</b> Paul Diglio; equest-users@lists.onebuilding.org<br><b>Subject:</b> Re: [Equest-users] question about inefficiency of duct<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>In addition to significant delta Ts, please also consider the additional airflow required to cool/heat a space when the supply air delta T (between the supply air and the conditioned space) is lowered due to duct losses.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Example: Say the cooling load requires 100 cfm to cool a space assuming a supply air temp of 55 and a perfectly insulated duct (that is, a duct with no change in temp as it leaves the AHU and gets to the space). The room is 70 degrees, so which makes the sensible cooling in the space about 1630 btu. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Now take this same room, and assume the duct gains 5 degrees between the AHU and the space (note, I am not talking about heat gain from fan energy here). Now the air being supplied to the space is 60 degrees, and to maintain the same sensible cooling capacity, the airflow must be 150 cfm, a 50% increase (!).<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>This heat is not lost to the space being cooled (most likely). The idea of *<b>neglible</b>* loss at the room level does not apply.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>At the system level, the idea of *<b>neglible</b>* energy loss may or may not apply. CLEARLY there is additional fan energy used. The heat that is lost from the duct to somewhere, may be recovered to a large degree (in the case of a 100% return air system, where the primary area of energy loss COULD be additional heat gained in the plenum due to increased delta t between the plenum and the OA temp) or it may be lost entirely (in the case of a 100% OA system, which is obviously already a big energy user and this simply adds to the problem). In the case of significant relief of the air the heat is lost to, there is also a large impact on cooling and heating energy as you are moving more air, and trying to maintain the same setpoints at the system level.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The notion that there is no net effect is really only true if the heat is being lost/gained directly at the location of the temperature sensor/tstat.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>(Most buildings these days have appropriate insulation on the ductwork which minimizes this effect, but it wasn’t that long ago when this wasn’t the case)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Paul Diglio<br><b>Sent:</b> Tuesday, March 29, 2011 7:32 PM<br><b>To:</b> John Bixler<br><b>Subject:</b> Re: [Equest-users] question about inefficiency of duct<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:10.0pt'>Nick:<br><br>For a supply duct passing through a plenum return ceiling during the cooling season, the temperature difference between the supply air and return air can be as much as 25 degrees.<br><br>During the heating season, this difference could be as much as 30 degrees during morning warm up.<br><br>Paul Diglio<o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:10.0pt'><o:p> </o:p></span></p><div><div class=MsoNormal align=center style='text-align:center'><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'><hr size=1 width="100%" align=center></span></div><p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Nick Caton <ncaton@smithboucher.com><br><b>To:</b> Paul Diglio <paul.diglio@sbcglobal.net>; "McArdle, Mike" <Mike.McAardle@state.vt.us>; xiaoyang shi <xs2144@gmail.com>; equest-users@lists.onebuilding.org<br><b>Sent:</b> Tue, March 29, 2011 8:03:32 PM<br><b>Subject:</b> RE: [Equest-users] question about inefficiency of duct</span><o:p></o:p></p><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>I think Mike’s general point is fair and isn’t to be taken in absolutes. </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>When a ducted return air stream is passing through a conditioned space or plenums/chases in between other conditioned spaces, it’s probably a safe bet to claim any duct gains/losses are *negligible* (not nonexistent), particularly if said return ducts are insulated, due to the relatively small delta-T.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>On the other hand, winter losses and summertime gains at extreme temperatures may be considerable if any ductwork is routed exterior to the building, even if insulated. </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Xiaoyang, if you wish to calculate it as a percentage at design conditions: ( U x A x deltaT )<sub>DUCT</sub> / (total building heating or cooling load) x 100</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>If you wanted to model such exterior duct heat losses/gains in eQuest… I haven’t considered that before – but depending on your system setup, it might be as simple as a small exterior wall surface with appropriate U-value and area equal to the duct surface area… in the event the solar loads incident on the duct might be significant, make a point to correctly locate the surface in 3D (over the roof, along a wall, etc.) to avoid any incorrect self-shading from other surfaces.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>If anyone has delved into this and knows a better/simpler way please do share =).</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>~Nick</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'><img border=0 width=119 height=37 id="Picture_x0020_1" src="cid:image001.jpg@01CBEEFE.3E0EEAE0" alt="cid:489575314@22072009-0ABB"></span><o:p></o:p></p><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#2D4D5E'> </span></b><o:p></o:p></p><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#2D4D5E'>NICK CATON, E.I.T.</span></b><o:p></o:p></p><p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#CC9900'>PROJECT ENGINEER</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#2D4D5E'>Smith & Boucher Engineers</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#2D4D5E'>25501 west valley parkway</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#2D4D5E'>olathe ks 66061</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#2D4D5E'>direct 913 344.0036</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#2D4D5E'>fax 913 345.0617</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>www.smithboucher.com</span><u><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:blue'> </span></u><o:p></o:p></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;border-color:-moz-use-text-color -moz-use-text-color'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Paul Diglio<br><b>Sent:</b> Tuesday, March 29, 2011 4:59 PM<br><b>To:</b> McArdle, Mike; xiaoyang shi; equest-users@lists.onebuilding.org<br><b>Subject:</b> Re: [Equest-users] question about inefficiency of duct</span><o:p></o:p></p></div></div><p class=MsoNormal> <o:p></o:p></p><div><div><p class=MsoNormal><span style='font-size:10.0pt'>Michael:<br><br>"if the air in duct is the same air as the air being supplied to the space, there is no net effect"? What do you mean by net effect?<br><br>The duct heat loss/gain depends on the difference of the temperature of the air in the duct and the temperature of the air surrounding the outside of the duct. It is highly unlikely that these temperature will be the same.<br><br>Paul Diglio</span><o:p></o:p></p></div><div><p class=MsoNormal><span style='font-size:10.0pt'> </span><o:p></o:p></p><div><div class=MsoNormal align=center style='text-align:center'><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'><hr size=1 width="100%" align=center></span></div><p class=MsoNormal style='margin-bottom:12.0pt'><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> "McArdle, Mike" <Mike.McAardle@state.vt.us><br><b>To:</b> xiaoyang shi <xs2144@gmail.com>; "equest-users@lists.onebuilding.org" <equest-users@lists.onebuilding.org><br><b>Sent:</b> Tue, March 29, 2011 5:39:40 PM<br><b>Subject:</b> Re: [Equest-users] question about inefficiency of duct</span><o:p></o:p></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Dear xiaoyang shi</span><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>It Depends on the temperature differentials between air in duct and space and insulation thickness </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>But more importantly , if the air in duct is the same air as the air being supplied to the space there is no net effect </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Thank you, Sincerely,</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Michael J. McArdle , P.E.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Buildings Engineer II, Project Manager </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>State of Vermont, </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Buildings and General Services (BGS)</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>2 Governor Aiken Avenue</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Montpelier, Vt. 05633</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Office: 802-828-5650; cell: 802-272-4828</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";color:#1F497D'> </span><o:p></o:p></p><div style='border:none;border-top:solid windowtext 1.0pt;padding:3.0pt 0in 0in 0in;border-color:-moz-use-text-color -moz-use-text-color'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>xiaoyang shi<br><b>Sent:</b> Tuesday, March 29, 2011 5:37 PM<br><b>To:</b> equest-users@lists.onebuilding.org<br><b>Subject:</b> [Equest-users] question about inefficiency of duct</span><o:p></o:p></p></div><p class=MsoNormal> <o:p></o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'>Hi folks,<br><br>In the winter time, some heat loss in HVAC is from duct.<br><br>What is the percentage of heat loss through the duct to the total building heat load, due to the inefficiencies of duct delivery system?<br><br>Thank you guys.<o:p></o:p></p></div></div></div></div></div></div></div></div><p class=MsoNormal><o:p> </o:p></p><div class=MsoNormal align=center style='text-align:center'><hr size=2 width="100%" align=center></div><div><p class=MsoNormal><span style='font-size:8.5pt;font-family:"Verdana","sans-serif";color:black'>If this email is spam, report it to <a href="https://support.onlymyemail.com/view/report_spam/MTM0MTU4OjEyNjM4MDAwNTA6amJpeGxlckBzZWJlc3RhLmNvbTpkZWxpdmVyZWQ"><span style='color:#336699'>www.OnlyMyEmail.com</span></a> <o:p></o:p></span></p></div></div></body></html>