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Fred,<br>
Type668 models a single stage heat pump. There are other versions of
the heat pump model designed to simulate the performance of multistage
heat pumps and there are controller models to go with them.<br>
Best,<br>
David<br>
<br>
<br>
On 10/15/2010 14:04, Fred Betz wrote:
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<p class="MsoNormal">Does anyone know of a way to make part load
operation work
in Type668?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The performance maps are based on entering
conditions on the
evaporator and condenser side. However, there is no direct way to make
type668
run at 10%, 50%, etc.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The work around I have used in the past is
dividing the
performance map by 50% to reflect two stages of operation and so on.
Then
setting up valves and controls to route the flow correctly. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The HP I am modeling has a 10:1 turn down ratio
and I don’t
want to make 10 heat pumps each with 10% of the total capacity of a
single
unit. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Please advise,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Fred<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style=""><b><span
style="font-size: 10pt; color: rgb(102, 0, 0); text-transform: uppercase;">Fred
Betz</span></b><b><span style="font-size: 9pt; color: rgb(51, 51, 51);">
</span></b><span style="font-size: 9pt; color: rgb(51, 51, 51);">PhD.,
LEED AP <br>
</span><span
style="font-size: 10pt; color: rgb(51, 51, 51); text-transform: uppercase;">Sustainable
Systems Analyst</span><span
style="font-size: 9pt; color: rgb(51, 51, 51);"><o:p></o:p></span></p>
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<p class="MsoNormal" style=""><b><span
style="font-size: 9pt; color: rgb(102, 0, 0);">AEI</span></b><span
style="font-size: 9pt; color: rgb(51, 51, 51);"> | AFFILIATED
ENGINEERS, INC. <br>
5802 Research Park Blvd. | Madison, WI 53719<br>
<br>
</span><span style="font-size: 9pt; color: rgb(102, 0, 0);">P:
608.236.1175 | F: 608.238.2614</span><span
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</span><span style="font-size: 9pt; color: rgb(102, 0, 0);"><a
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| </span><b><span style="font-size: 9pt; color: rgb(102, 0, 0);"><a
moz-do-not-send="true" href="http://www.aeieng.com/"><span
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***************************
David BRADLEY
Principal
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