You must use the 1.15 and 1.25 multipliers to meet LEED requirements. I would look at the throttling range that eQ is defaulting to. if it's .5 F, which is I think what it is for PSZ, I would raise that to1 or 2 F, which is reasonable. Then I would look at the space loads, equipment especially and make sure all that looks good, then I'd look at the schedules, make sure they are good, and then I'd look at the cfm/sf. It's not unreasonable to match it to your proposed building and I don't know of any issue LEED has with doing that.<br>
<br>Carol<br><br><div class="gmail_quote">On Tue, Sep 7, 2010 at 4:23 PM, Kathryn Kerns <span dir="ltr"><<a href="mailto:kathryn.kerns@bceengineers.com">kathryn.kerns@bceengineers.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
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<p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">Yes, Carol I know the default airflow
value is very low. Usually the eQuest airflow auto sizing routine will select
larger values than the default. The problem is: what if the eQuest baseline energy
model selects airflows larger than the default cfm/sqft airflow values but the
baseline energy model still ends up with greater than 300 unmet hours or the
baseline energy model has more than 50 unmet hours greater than the proposed energy
model? </span></font></p>
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<p class="MsoNormal"><font size="2" color="navy" face="Arial"><span style="font-size: 10pt; font-family: Arial; color: navy;">Do you start increasing the baseline energy
model airflows above the auto sized airflow value in the thermal blocks that
are having unmet hours issues, or do you retain the auto sized airflow value
and start manually increasing the baseline heating and cooling capacities that
were also auto sized by eQuest using the 1.15 and 1.25 oversized coefficients?</span></font></p><div class="im">
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<p style="margin: 0in 0in 0.0001pt;"><b><b><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black;">Kathryn Kerns</span></font></b></b><font color="navy"><span style="color: navy;"></span></font></p>
<p style="margin: 0in 0in 0.0001pt;"><i><b><i><font size="2" color="navy" face="Arial"><span style="font-size: 11pt; font-family: Arial; color: navy; font-weight: bold; font-style: normal;">Systems Specialist</span></font></i></b></i><font color="navy"><span style="color: navy;"></span></font></p>
<p style="margin: 0in 0in 0.0001pt;"><i><b><i><font size="3" color="teal" face="Times New Roman"><span style="font-size: 12pt; font-variant: small-caps; color: teal; font-weight: bold; font-style: normal;">BCE</span></font></i></b></i><b><b><font size="2" color="teal" face="Times New Roman"><span style="font-size: 10pt; font-variant: small-caps; color: teal;"> </span></font><font color="teal"><span style="font-variant: small-caps; color: teal;">Engineers, Inc.</span></font></b></b></p>
<p style="margin: 0in 0in 0.0001pt;"><b><b><font size="1" color="black" face="Times New Roman"><span style="font-size: 9pt; color: black;">| Ph: 253.922.0446 | Fx: 253.922.0896 |</span></font></b></b><font size="1" color="black"><span style="font-size: 7pt; color: black;"> </span></font></p>
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<p class="MsoNormal"><b><font size="2" face="Tahoma"><span style="font-size: 10pt; font-family: Tahoma; font-weight: bold;">From:</span></font></b><font size="2" face="Tahoma"><span style="font-size: 10pt; font-family: Tahoma;"> Carol Gardner
[mailto:<a href="mailto:cmg750@gmail.com" target="_blank">cmg750@gmail.com</a>] <br>
<b><span style="font-weight: bold;">Sent:</span></b> Tuesday, September 07, 2010
2:22 PM<br>
<b><span style="font-weight: bold;">To:</span></b> Kathryn Kerns<div class="im"><br>
<b><span style="font-weight: bold;">Cc:</span></b> <a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a><br>
</div><div class="im"><b><span style="font-weight: bold;">Subject:</span></b> Re: [Equest-users]
Confirmation for finding the Baseline Energy Model Supply Airfllow</div></span></font></p>
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<p class="MsoNormal" style="margin-bottom: 12pt;"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">Kathryn,<div><div></div><div class="h5"><br>
<br>
I think that .5 cfm/sf is too low. I never saw it used when I was designing
HVAC systems except for an occasionally used interior space. I immediately
change it to1.0 cfm/sf which I feel is a good place to start. For highly loaded
rooms with lots of internal gain I sometimes up that amount after I have
checked the other possible inputs.<br>
<br>
Carol</div></div></span></font></p><div><div></div><div class="h5">
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<p class="MsoNormal"><font size="3" face="Times New Roman"><span style="font-size: 12pt;">On Tue, Sep 7, 2010 at 1:55 PM, Kathryn Kerns <<a href="mailto:kathryn.kerns@bceengineers.com" target="_blank">kathryn.kerns@bceengineers.com</a>>
wrote:</span></font></p>
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<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;">Everyone, </span></font></p>
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<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;">We are
having a discussion at the office about how to define the supply airflow and
energy model baseline. I pick the baseline system type per Appendix G (packaged
single zone, packaged VAV, etc., set the heating sizing ratio to 1.25 and the
cooling sizing ratio to 1.15, leave the heating and cooling capacities blank so
the model will auto-size, and then set the default airflow to 0.5 cfm/sqft and
let eQuest run. I then check to see if the baseline energy model unmet hours
are less than 300 and are within 50 hours of the proposed model. If the
baseline energy model is above 300 unmet hours or isn’t within 50 hours
of the proposed model, I will then start tweaking the airflow in the baseline
energy model thermal blocks that are causing the unmet hour issues to solve the
problem. </span></font></p>
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<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;">Is this what
everyone else is doing or do leave the airflow with the default values it
calculated with the 0,5 cfm/sqft limit and enter capacity values in the
previously blank HVAC cooling and heating capacities slots so the baseline
energy model stops auto-sizing? </span></font></p>
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<p class="MsoNormal"><font size="2" face="Arial"><span style="font-size: 10pt; font-family: Arial;">Thanks.</span></font></p>
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<p style="margin: 0in 0in 0.0001pt;"><b><font size="3" color="black" face="Arial"><span style="font-size: 12pt; font-family: Arial; color: black; font-weight: bold;">Kathryn Kerns</span></font></b></p>
<p style="margin: 0in 0in 0.0001pt;"><b><font size="2" face="Arial"><span style="font-size: 11pt; font-family: Arial; font-weight: bold;">Systems Specialist</span></font></b></p>
<p style="margin: 0in 0in 0.0001pt;"><b><font size="3" color="teal" face="Times New Roman"><span style="font-size: 12pt; font-variant: small-caps; color: teal; font-weight: bold;">BCE</span></font></b><b><font size="2" color="teal"><span style="font-size: 10pt; font-variant: small-caps; color: teal; font-weight: bold;"> </span></font><font color="teal"><span style="font-variant: small-caps; color: teal;">Engineers, Inc.</span></font></b></p>
<p style="margin: 0in 0in 0.0001pt;"><b><font size="1" color="black" face="Times New Roman"><span style="font-size: 9pt; color: black; font-weight: bold;">| Ph: 253.922.0446 | Fx: 253.922.0896 |</span></font></b><font size="1" color="black"><span style="font-size: 7pt; color: black;"> </span></font></p>
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<br>
-- <br>
Carol Gardner PE</span></font></p>
</div></div></div>
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</blockquote></div><br><br clear="all"><br>-- <br>Carol Gardner PE<br>
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