<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
p.Normal, li.Normal, div.Normal
{mso-style-name:"\[Normal\]";
margin:0in;
margin-bottom:.0001pt;
text-autospace:none;
font-size:12.0pt;
font-family:"Arial","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>I am following up on the comments from a LEED for Homes Midrise review for a recent model. This is the first time I have provided a full .SIM file to go with my model to a reviewer (LEED for Homes requests so many reports from the output that I thought this would be easier), and now I am being asked to explain every single caution and warning associated with the simulation. All of the following are associated with my DOAS units, which are giving me a real headache.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'>**CAUTION**********************************************************************<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> ERU 1 defined as an OA-FROM-SYSTEM<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> has 9 CONDITIONED ZONEs - only one was expected.<o:p></o:p></span></p><p class=Normal style='text-indent:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal>Each of my DOAS units serves multiple corridor zones and directly provides outside air to the building’s residential apartments. I am using system type, packaged multizone. Is this caution something I should be worried about?<span style='font-size:8.0pt;font-family:"Courier New"'><o:p></o:p></span></p><p class=Normal style='text-indent:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=Normal style='text-indent:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'>**WARNING**********************************************************************<o:p></o:p></span></p><p class=Normal style='margin-left:99.0pt'><span style='font-size:8.0pt;font-family:"Courier New"'>In ERU 1 , the return humidity for a coil exit T of 52.0 is 0.0095 <o:p></o:p></span></p><p class=Normal style='margin-left:99.0pt'><span style='font-size:8.0pt;font-family:"Courier New"'>Your setpoint is 0.0089, which may not be held.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>This is for a DOAS that includes energy recovery, DX cooling, Furnace heating, and humidity control via hot gas reheat. I have maximum humidity set to 49% per the design documents. Creating an hourly report for supply air humidity, I found that the humidity setpoint (lb H20/lb dry air) does not exceed 0.0089. Even with lowering the coil exit temp, I could not manage to get it to go away.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'>**WARNING**********************************************************************<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> ERU 2 defined as an OA-FROM-SYSTEM<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> has OA flow requirement of 2839. CFM but its calculated/specified<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> OA flow is only 2600. CFM.<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> Its MIN-OUTSIDE-AIR has been reset to meet the requirement, however<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> it is strongly recommended you re-run with this MIN-OUTSIDE-AIR specified.<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’m getting this on all my DOAS units, and I’ve tried multiple approaches to overcoming this warning without success. Even setting the outside air ratio to 1.0, eQUEST continues to set the system outside air to this same number, 2839 cfm. The actual system flow is set to 4,515 CFM per the design documents.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'>**WARNING**********************************************************************<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> Energy-recovery ventilator: ERU 1 is<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> enabled to run, but cannot run because there is no central<o:p></o:p></span></p><p class=Normal style='margin-left:.5in'><span style='font-size:8.0pt;font-family:"Courier New"'> exhaust flow. First occurrence: 1/ 1/ 1<o:p></o:p></span></p><p class=Normal><span style='font-size:8.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal>I have an exhaust air flow specified on the Heat Recovery 1 tab under outdoor air. I also have the exhaust schedule set to 1.0 for the entirety of the year. Am I not enabling something correctly?<span style='font-size:8.0pt;font-family:"Courier New"'><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>As always many thanks in advance.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Robert Stephenson<o:p></o:p></p><p class=MsoNormal>Technical Energy Analyst<o:p></o:p></p><p class=MsoNormal>Evaluation, Measurement & Verification Services<o:p></o:p></p><p class=MsoNormal><b>Vermont Energy Investment Corporation<o:p></o:p></b></p><p class=MsoNormal>rstephenson@veic.org<o:p></o:p></p><p class=MsoNormal>(802) 540-7886<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>