Hi Nick,<br><br>It used to be, and looks like it still is based on the documentation, that you would input your exhaust cfm at the system level as return air cfm. <br><br>Hope that works!<br><br>Carol<br><br><div class="gmail_quote">
On Tue, Mar 16, 2010 at 7:02 PM, Nick Caton <span dir="ltr"><<a href="mailto:ncaton@smithboucher.com">ncaton@smithboucher.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-US">
<div>
<p class="MsoNormal">I need have an ERV which moves all the exhaust and supplies
conditioned OA to 2 of 3 FPVAV air handlers. I’ve specified the
appropriate enthalpy wheel specifics at the two affected PIU systems, maintaining
identical efficiency properties and breaking down CFM’s and fan/auxiliary
power figures by weighting each by the supplied OA amount.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">I understand from the help files that zonally-specified
exhaust air does not play into heat-recovery, when we specify energy recovery
at the system level (help section is copied below and highlighted for
reference).</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">I take it then I’m supposed to zero out all zonally
entered exhaust air flows, sum up the flows and add at the system level…
but then <u>how/where do I specify system-level exhaust CFM rates</u>? </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">I’ve tried to enter EXHAUST-FLOW
= #### under the systems in question in the .inp file, but it introduces the
following error: </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">*13131*
EXHAUST-FLOW = 2550</p>
<p class="MsoNormal">*ERROR********* ============
*****************************************************************UNKNOWN
KEYWORD or PREVIOUS .. MISSING </p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">More errors ensue, and a long string of things appear to be
defaulted/lost when I continue to open the file… something is obviously
wrong with this approach.<b><span style="color: rgb(45, 77, 94);"></span></b></p>
<p class="MsoNormal"><b><span style="color: rgb(45, 77, 94);"> </span></b></p>
<p class="MsoNormal"><img src="cid:image001.jpg@01CAC549.4067CF30" alt="cid:489575314@22072009-0ABB" width="119" height="37"><b><span style="color: rgb(45, 77, 94);"></span></b></p>
<p class="MsoNormal"><b><span style="color: rgb(45, 77, 94);"> </span></b></p>
<p class="MsoNormal"><b><span style="color: rgb(45, 77, 94);">NICK CATON, E.I.T.</span></b><b><span style="font-size: 12pt; color: rgb(45, 77, 94);"></span></b></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: rgb(204, 153, 0);">PROJECT ENGINEER</span><span style="font-size: 7.5pt; font-family: "Times New Roman","serif"; color: rgb(204, 153, 0);"></span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">25501 west
valley parkway</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">olathe ks 66061</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">direct 913
344.0036</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">fax 913
345.0617</span></p>
<p class="MsoNormal"><i><span style="font-size: 10pt; color: rgb(45, 77, 94);">Check out
our new web-site @ </span></i><span style="color: rgb(31, 73, 125);"><a href="http://www.smithboucher.com" title="blocked::www.smithboucher.com" target="_blank"><span style="font-size: 10pt; color: blue;">www.smithboucher.com</span></a></span><u><span style="font-size: 10pt; color: blue;"> </span></u><span style="color: rgb(31, 73, 125);"></span></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><b><span style="font-size: 10pt; font-family: "Times New Roman","serif";">EXHAUST-FLOW</span></b></p>
<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";">Flow rate of the
zone's exhaust fan. This entry can be omitted if there is no exhaust from the
zone, if there is only central exhaust by way of the system return, or if the
exhaust tracks the supply flow (see AIRFLOW-TRACKING). If specified,
EXHAUST-STATIC should also be entered. The exhaust fan may be either constant
flow or variable flow. </span></p>
<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";">If exhaust air
make-up is via the air handler (EXHAUST-SOURCE = AIR-HANDLER), then the exhaust
fan can operate only only when the system supply and return fans operate (see
SYSTEM:FAN-SCHEDULE or SYSTEM:EXHAUST-FAN-SCH).</span></p>
<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif"; color: red;">The
SYSTEMS program simulates heat recovery from central exhaust only, not from
zone exhaust. If heat is to be recovered, zone exhaust should not be entered
but rather allowed to default to the central system. Return fan static should
be adjusted, on a weighted average basis, to reflect zone exhaust fan
conditions. </span></p>
<p class="MsoNormal"><span style="font-size: 12pt; font-family: "Times New Roman","serif";">The program will
not allow SYSTEM:MIN-OUTSIDE-AIR to be less than the sum of EXHAUST-FLOWs for
all zones divided by the sum of supply flows for all zones. That is,
MIN-OUTSIDE-AIR will not restrict the operation of exhaust fans. The exception
is when EXHAUST-SOURCE = INFILTRATION, in which case zonal exhaust does not
affect air handler outside air requirements.</span></p>
<p class="MsoNormal"> </p>
</div>
</div>
<br>_______________________________________________<br>
Equest-users mailing list<br>
<a href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org" target="_blank">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a><br>
To unsubscribe from this mailing list send a blank message to <a href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</a><br>
<br></blockquote></div><br>