<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style>
<!--
@font-face
{font-family:"Cambria Math"}
@font-face
{font-family:Calibri}
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif}
a:link, span.MsoHyperlink
{color:#0563C1;
text-decoration:underline}
a:visited, span.MsoHyperlinkFollowed
{color:#954F72;
text-decoration:underline}
p.msonormal0, li.msonormal0, div.msonormal0
{margin-right:0in;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman",serif}
span.EmailStyle18
{font-family:"Calibri",sans-serif;
color:windowtext}
span.EmailStyle19
{font-family:"Calibri",sans-serif;
color:windowtext}
.MsoChpDefault
{font-size:10.0pt}
@page WordSection1
{margin:1.0in 1.0in 1.0in 1.0in}
div.WordSection1
{}
-->
</style>
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72">
<div>
<div style="font-family:Calibri,sans-serif; font-size:11pt">Hi Melissa,<br>
<br>
This makes sense. There's only small amount of energy usage increased in dhw with vfd pump. Thanks for your help.<br>
<br>
Pramod<br>
</div>
</div>
<div dir="ltr">
<hr>
<span style="font-family:Calibri,sans-serif; font-size:11pt; font-weight:bold">From:
</span><span style="font-family:Calibri,sans-serif; font-size:11pt"><a href="mailto:MCrowe@engsolutions.com">Melissa Crowe</a></span><br>
<span style="font-family:Calibri,sans-serif; font-size:11pt; font-weight:bold">Sent:
</span><span style="font-family:Calibri,sans-serif; font-size:11pt">29-04-16 ಅಪರಾಹ್ನ 07:11</span><br>
<span style="font-family:Calibri,sans-serif; font-size:11pt; font-weight:bold">To:
</span><span style="font-family:Calibri,sans-serif; font-size:11pt"><a href="mailto:d.pramod@setty.com">Pramod .D</a></span><br>
<span style="font-family:Calibri,sans-serif; font-size:11pt; font-weight:bold">Subject:
</span><span style="font-family:Calibri,sans-serif; font-size:11pt">RE: [Equest-users] VFD vs constant pump</span><br>
<br>
</div>
<div>
<div class="WordSection1">
<p class="MsoNormal">Hi Pramod</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Pump energy to the water, heats the water (there is a temperature rise across the pump). When pump energy is reduced more boiler energy is required to maintain the same water temperature. For the same reason when going from constant
flow to VFD flow in CHW systems this results in a small cooling savings.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Melissa</p>
<p class="MsoNormal"> </p>
<div>
<div style="border:none; border-top:solid #E1E1E1 1.0pt; padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Pramod .D via Equest-users [mailto:equest-users@lists.onebuilding.org]
<br>
<b>Sent:</b> Thursday, April 28, 2016 5:21 AM<br>
<b>To:</b> equest-users@lists.onebuilding.org<br>
<b>Subject:</b> [Equest-users] VFD vs constant pump</p>
</div>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Hi All,</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">I am simulating a model to see the savings provided by VFD pump connected to the DHW plant loop. The energy used by the VFD pump is less compared to constant volume pump. The problem is the energy usage of DHW increases if constant volume
pump is changed to VFD. Is this correct or am I missing anything? How does VFD pumps increases DHW usage?</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Thanks!</p>
<p class="MsoNormal">Pramod</p>
</div>
</div>
</body>
</html>