<html><body><div style="color:#000; background-color:#fff; font-family:Courier New, courier, monaco, monospace, sans-serif;font-size:13px"><div class="" style="">Thank you very much David, that is very clear.</div><div class="" style=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: 'Courier New', courier, monaco, monospace, sans-serif; font-style: normal; background-color: transparent;" class=""><br class="" style=""></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: 'Courier New', courier, monaco, monospace, sans-serif; font-style: normal; background-color: transparent;" class="">Regards,</div><blockquote type="cite" style="font-family: 'Helvetica Neue', 'Segoe UI', Helvetica, Arial, 'Lucida Grande', sans-serif;" class=""><div style="font-family: 'Courier New', courier, monaco, monospace, sans-serif;" class=""><div class="" style="background-color: transparent;">Thank you</div><div class=""
style="">Metkel Yebiyo BEng (Hons), MSc</div><div class="" style=""><span style="font-size: small;" class="">CEREB PhD Researcher - Ground Source Heat Pumps</span></div><div class="" style=""><span style="font-size: small;" class="">Room T615</span></div><div class="" style=""><span style="font-size: small;" class="">Department of Urban Engineering</span></div><div class="" style=""><span style="font-size: small;" class="">Faculty of Engineering, Science and the Built Environment</span></div><div class="" style=""><span style="font-size: small;" class="">London South Bank University,</span></div><div class="" style=""><span style="font-size: small;" class="">103 Borough Road,</span></div><div class="" style=""><span style="font-size: small;" class="">London SE1 0AA</span></div><div class="" style=""><span style="font-size: small;" class="">Tel: +44 (0)20 7815 7639</span></div><div class="" style=""><span style="font-size: small;" class="">E: <a
rel="nofollow" shape="rect" class="" ymailto="mailto:yebiyom@lsbu.ac.uk" target="_blank" href="mailto:yebiyom@lsbu.ac.uk" style="color: rgb(25, 106, 212);">yebiyom@lsbu.ac.uk</a></span></div><div class="" style="background-color: transparent;"></div><div class="" style=""> </div></div></blockquote> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: Courier New, courier, monaco, monospace, sans-serif; font-size: 13px;" class=""> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 12px;" class=""> <div dir="ltr" class="" style=""> <font size="2" face="Arial" class="" style=""> On Thursday, 2 October 2014, 13:45, David BRADLEY <d.bradley@tess-inc.com> wrote:<br class="" style=""> </font> </div> <br class="" style=""><br class="" style=""> <div class="" style=""><div id="yiv9402266861" class="" style=""><div class=""
style="">
Matkel,<br clear="none" class="" style="">
The fan power is computed from an equation of the form:<br clear="none" class="" style="">
<br clear="none" class="" style="">
pFan = pFan_rtd*(a0 + a1*yFan + a2*yFan^2 + a3*yFan^3 + ... +
aN*yFan^N)<br clear="none" class="" style="">
<br clear="none" class="" style="">
where yFan is the fan control signal. If your fan is a simple
on/off (single speed) device then you want to define a0=0 and a1=1.
If your fan is a variable speed device and can have a control signal
anywhere between 0 and 1 then you should set the power coefficients
as a0=a1=a2=0 and a3=1. This relationship comes from the fan
affinity laws.<br clear="none" class="" style="">
Kind regards,<br clear="none" class="" style="">
David<br clear="none" class="" style="">
<br clear="none" class="" style="">
<br clear="none" class="" style="">
<div class="" id="yiv9402266861yqt02073" style=""><div class="" style="">On 10/2/2014 05:27, metkell yebiyo
wrote:<br clear="none" class="" style="">
</div>
<blockquote type="cite" class="" style="">
<div style="color:#000;background-color:#fff;font-family:Courier New, courier, monaco, monospace, sans-serif;font-size:10px;" class="">
<div class="" style=""><span class="" style="font-size:13px;">Dear
TRNSYS users,</span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><span class="" style="font-size:13px;"><br clear="none" class="" style="">
</span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><span class="" style="font-size:13px;">I am simulating a GSHP
system connected to a 300kW Dry air cooler Type 511.</span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><span class="" style="font-size:13px;">The Dry air Cooler is
controlled when the return temperature from the ground
reaches 30degC, </span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><span class="" style="font-size:13px;">then the Dry air cooler
comes on, to maintain the fluid temperature going to the
ground to 22degC.</span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><span class="" style="font-size:13px;"><br clear="none" class="" style="">
</span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><span class="" style="font-size:13px;">My question is, I am
trying to obtain the amount of power drawn by the fan when
the Dry air Cooler is operating. But in order for TRNSYS, to
calculate the power drawn, you need to put the power
coefficients a1, a2 and a3, how would I obtain this values?
Is it a matter of calling the Dry air cooler manufacturer
and ask them for this power coefficients or what do I need
to do please?</span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><br clear="none" class="" style="">
</div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><br clear="none" class="" style="">
</div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><br clear="none" class="" style="">
</div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;">Thank
you</div>
<div class="" style=""><span style="font-size:13px;" class="">Metkel
Yebiyo BEng (Hons), MSc</span></div>
<div class="" style=""><span style="font-size:small;" class="">CEREB PhD
Researcher - Ground Source Heat Pumps </span></div>
<div class="" style=""><span style="font-size:small;" class="">Room T615
</span></div>
<div class="" style=""><span style="font-size:small;" class="">Department
of Urban Engineering </span></div>
<div class="" style=""><span style="font-size:small;" class="">Faculty
of Engineering, Science and the Built Environment</span></div>
<div class="" style=""><span style="font-size:small;" class="">London
South Bank University, </span></div>
<div class="" style=""><span style="font-size:small;" class="">103
Borough Road,</span></div>
<div class="" style=""><span style="font-size:small;" class="">London
SE1 0AA</span></div>
<div class="" style=""><span style="font-size:small;" class="">Tel: +44
(0)20 7815 7639</span></div>
<div class="" style=""><span style="font-size:small;" class="">E: <a rel="nofollow" shape="rect" class="" ymailto="mailto:yebiyom@lsbu.ac.uk" target="_blank" href="mailto:yebiyom@lsbu.ac.uk" style="">yebiyom@lsbu.ac.uk</a></span></div>
<div class="" style="background-color:transparent;">
</div>
<div class="" style=""> </div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><span class="" style="font-size:13px;"><br clear="none" class="" style="">
</span></div>
<div class="" style="color:rgb(0, 0, 0);font-size:13px;font-family:'Courier New', courier, monaco, monospace, sans-serif;font-style:normal;background-color:transparent;"><br clear="none" class="" style="">
</div>
</div>
<br clear="none" class="" style="">
<fieldset class="" style=""></fieldset>
<br clear="none" class="" style="">
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</blockquote></div>
<br clear="none" class="" style="">
<pre class="" style="">--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI 53703 USA
P:+1.608.274.2577
F:+1.608.278.1475
<a rel="nofollow" shape="rect" class="" ymailto="mailto:d.bradley@tess-inc.com" target="_blank" href="mailto:d.bradley@tess-inc.com" style="">d.bradley@tess-inc.com</a>
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