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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Otto, it didn’t work!</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Dear all,</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I discovered that the parameter “Hot
Deck Max Leaving Temp” is necessary in order to activate the main heating
coil! If left to default, only the reheat coils will operate.</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Back to my case, where I had electric
reheat. When I didn’t specify the “Hot Deck Max Leaving Temp”,
the hot water loop had zero flow because it wasn’t activated (and hence
the error).</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Now when I specified a value of 70F, I got
rid of the error, but the whole heating (99.9%) was electric, and a very small
0.1% was due to the hot water loop.</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>A possible percentage of space heating
sources is 80% hot water loop, 20% electric reheat coil. (or any other
reasonable percentage).</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I played a lot with the “reheat
delta temp” and the “Hot Deck Max Leaving Temp”, the results
slightly varied (change in the fuel consumption of space heat, but still
negligible compared to the electric portion.</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Any recommendations? I attach my files
just in case…</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> </span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Many thanks,</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Omar</span></font></p>
<div>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>___________________________</span></font></p>
<p class=MsoNormal><st1:PersonName style="BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x; BACKGROUND-POSITION: left bottom"><st1:PersonName style="BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x; BACKGROUND-POSITION: left bottom"><st1:PersonName style="BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x; BACKGROUND-POSITION: left bottom"><st1:PersonName style="BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x; BACKGROUND-POSITION: left bottom"><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'>Omar Katanani<br>
</st1:PersonName></st1:PersonName></st1:PersonName></st1:PersonName>Sustainable
Design Engineer</span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Email: <st1:PersonName style="BACKGROUND-IMAGE: url(res://ietag.dll/#34/#1001); BACKGROUND-REPEAT: repeat-x; BACKGROUND-POSITION: left bottom"><a
href="mailto:omar@ecoconsulting.net">omar@ecoconsulting.net</a></span></font></st1:PersonName></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'> </span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Arial><span lang=EN-US
style='font-size:7.5pt;font-family:Arial;color:navy'>EcoConsulting (</span></font><font
size=1 color=navy face=Arial><span lang=EN-US style='font-size:7.5pt;
font-family:Arial;color:navy'>Lebanon</span></font><font size=1 color=navy
face=Arial><span lang=EN-US style='font-size:7.5pt;font-family:Arial;
color:navy'>)</span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Arial><span lang=EN-US
style='font-size:7.5pt;font-family:Arial;color:navy'>Nahas</span></font><font
size=1 color=navy face=Arial><span lang=EN-US style='font-size:7.5pt;
font-family:Arial;color:navy'> </span></font><font size=1 color=navy
face=Arial><span lang=EN-US style='font-size:7.5pt;font-family:Arial;
color:navy'>Building</span></font><font size=1 color=navy face=Arial><span
lang=EN-US style='font-size:7.5pt;font-family:Arial;color:navy'>, 4<sup>th</sup>
floor</span></font></p>
<p class=MsoNormal><font
size=1 color=navy face=Arial><span lang=EN-US style='font-size:7.5pt;
font-family:Arial;color:navy'>4 St-Maron Street</span></font><font size=1
color=navy face=Arial><span lang=EN-US style='font-size:7.5pt;font-family:Arial;
color:navy'> / </span></font><font
size=1 color=navy face=Arial><span lang=EN-US style='font-size:7.5pt;
font-family:Arial;color:navy'>Georges Haddad Avenue</span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Arial><span lang=EN-US
style='font-size:7.5pt;font-family:Arial;color:navy'>Postal Code: 2028 5806
SAIFI</span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Arial><span lang=EN-US
style='font-size:7.5pt;font-family:Arial;color:navy'>Beirut</span></font><font
size=1 color=navy face=Arial><span lang=EN-US style='font-size:7.5pt;
font-family:Arial;color:navy'>, </span></font><font size=1 color=navy
face=Arial><span lang=EN-US style='font-size:7.5pt;font-family:Arial;
color:navy'>Lebanon</span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Arial><span lang=EN-US
style='font-size:7.5pt;font-family:Arial;color:navy'>Tel: </span></font><font
size=1 color=navy face=Arial><span style='font-size:7.5pt;font-family:Arial;
color:navy'>+961 (0) 1 971 255<br>
</span></font><font size=1 color=navy face=Arial><span style='font-size:7.5pt;
font-family:Arial;color:navy'>Mobile</span></font><font size=1 color=navy
face=Arial><span style='font-size:7.5pt;font-family:Arial;color:navy'>:
+961 (0) 3 045 045</span></font></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'> </span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Arial><span style='font-size:
7.5pt;font-family:Arial;color:navy'>EcoConsulting (</span></font><font size=1
color=navy face=Arial><span style='font-size:7.5pt;font-family:Arial;
color:navy'>UK</span></font><font size=1 color=navy face=Arial><span
style='font-size:7.5pt;font-family:Arial;color:navy'>) Ltd<br>
28 </span></font><font
size=1 color=navy face=Arial><span style='font-size:7.5pt;font-family:Arial;
color:navy'>Marshalsea Road</span></font><font size=1 color=navy face=Arial><span
style='font-size:7.5pt;font-family:Arial;color:navy'><br>
</span></font><font size=1 color=navy face=Arial><span style='font-size:7.5pt;
font-family:Arial;color:navy'>London</span></font><font size=1 color=navy
face=Arial><span style='font-size:7.5pt;font-family:Arial;color:navy'>, </span></font><font
size=1 color=navy face=Arial><span style='font-size:7.5pt;font-family:Arial;
color:navy'>SE1 1HF</span></font><font size=1 color=navy face=Arial><span
style='font-size:7.5pt;font-family:Arial;color:navy'><br>
Tel: +44 (0) 207 939 0989<br>
Fax: +44 (0) 207 939 0981</span></font></p>
<p class=MsoNormal><font size=1 color=navy face=Arial><span style='font-size:
7.5pt;font-family:Arial;color:navy'>Website: <a
href="http://www.ecoconsulting.net/">www.ecoconsulting.net</a></span></font></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'> </span></font></p>
<p style='margin:0cm;margin-bottom:.0001pt'><font size=2 color=navy face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:navy'> <img border=0
width=870 height=102 src="cid:image001.jpg@01CB2A9F.F99E2A10"></span></font></p>
</div>
<p class=MsoNormal><font size=2 face=Tahoma><span lang=EN-US style='font-size:
10.0pt;font-family:Tahoma'>-----Original Message-----<br>
<b><span style='font-weight:bold'>From:</span></b> Otto Schwieterman
[mailto:oschwieterman@fhai.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> 21 July 2010 17:56<br>
<b><span style='font-weight:bold'>To:</span></b> Omar Katanani; </span></font><font
size=2 face=Tahoma><span lang=EN-US style='font-size:10.0pt;font-family:Tahoma'>equest-users@lists.onebuilding.org</span></font><font
size=2 face=Tahoma><span lang=EN-US style='font-size:10.0pt;font-family:Tahoma'><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: [Equest-users] VAV
with Electric Reheat</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>Omar,</span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'>You can try using a
pre-heat coil as your hot water coil in the air handler and the electric heat
in your re-heat coil.</span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><img border=0
width=536 height=401 id="Picture_x0020_1"
src="cid:image002.jpg@01CB2A9F.F99E2A10"></span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'><img border=0
width=539 height=403 id="Picture_x0020_2"
src="cid:image003.jpg@01CB2A9F.F99E2A10"></span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<p class=MsoNormal><font size=2 color="#1f497d" face=Calibri><span lang=EN-US
style='font-size:11.0pt;font-family:Calibri;color:#1F497D'> </span></font></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><font size=2 face=Tahoma><span lang=EN-US
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span lang=EN-US style='font-size:10.0pt;font-family:Tahoma'>
Omar Katanani [mailto:omar@ecoconsulting.net] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, July 21, 2010
10:06 AM<br>
<b><span style='font-weight:bold'>To:</span></b> Omar Katanani;
equest-users@lists.onebuilding.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> [Equest-users] VAV with
Electric Reheat</span></font></p>
</div>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-US
style='font-size:12.0pt'> </span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-US
style='font-size:12.0pt'> </span></font></p>
<p style='margin-bottom:12.0pt'><font size=2 face="Times New Roman"><span
lang=EN-US style='font-size:10.0pt'>Dear all,<br>
<br>
I'm sorry I've been nagging a lot lately, but believe me, you guys are my only
support!<br>
<br>
I was using a VAV system, with the reheat source being the hot water loop. I
specified the Reheat delta temperature by trial and error to 25F. Everything is
fine.<br>
<br>
Now I got updated info from the client saying that the source of the reheat is
electric. I am getting an error message:<br>
<br>
"Hot Water Loop has zero design flow. Check input for consistency,
or specify design loads."<br>
<br>
I read a couple of discussions. I understand that many factors will affect this
issue. The "Hot Deck Maximum Supply Temp", the "Reheat Delta
Temp", and the "Zone Entering Max Supply Temp".<br>
<br>
I tried specifying the hot deck max supply temp to 70F, I got the results
attached in the pdf. However, the gas consumption part of the space heating is
negligible compared to the electric, while I thought both will be of
significant ratios!<br>
<br>
My main question is how to get reasonable results, knowing that the main
heating source is the hot water loop, and the electric reheat is to fine tune
the temperature of zones experiencing different loads or so...<br>
<br>
I know that the design temperature of the zones is 70F, and that the
temperature that is supplied to the zone should be 30 degrees higher than the
zone temperature (70+30=100F).<br>
<br>
Any advice on how to choose the "reheat delta temp" and the "hot
deck maximum supply temp", or any other input parameter you feel that it
affects, is greatly appreciated.<br>
<br>
Many thanks,<br>
Omar<br>
___________________________<br>
<br>
Omar Katanani<br>
Sustainable Design Engineer<br>
Email: omar@ecoconsulting.net<br>
<br>
<br>
EcoConsulting (Lebanon)<br>
Nahas Building, 4th floor<br>
4 St-Maron Street / Georges Haddad Avenue<br>
Postal Code: 2028 5806 SAIFI<br>
Beirut, Lebanon<br>
Tel: +961 (0) 1 971 255<br>
Mobile: +961 (0) 3 045 045<br>
<br>
<br>
EcoConsulting (UK) Ltd<br>
28 Marshalsea Road<br>
London, SE1 1HF<br>
Tel: +44 (0)207 939 0989<br>
Fax: +44 (0)207 939 0981<br>
Website: www.ecoconsulting.net<br>
<br>
<br>
<br>
-----Original Message-----<br>
From: Omar Katanani<br>
Sent: Thu 7/15/2010 11:44 AM<br>
To: equest-users@lists.onebuilding.org<br>
Subject: VAV with Electric Reheat<br>
<br>
<br>
Dear all,<br>
<br>
I was using a VAV system, with the reheat source being the hot water loop. I
specified the Reheat delta temperature by trial and error to 20F. Everything is
fine.<br>
<br>
Now I got updated info from the client saying that the source of the reheat is
electric. I am getting an error message:<br>
<br>
"Hot Water Loop has zero design flow. Check input for consistency,
or specify design loads."<br>
<br>
I read a couple of discussions. I understand that many factors will affect this
issue. The "Hot Deck Maximum Supply Temp", the "Reheat Delta
Temp", and the "Zone Entering Max Supply Temp".<br>
<br>
First of all, is the sum of the first two equal to the third?<br>
<br>
My main question is how to get reasonable results, knowing that the main
heating source is the hot water loop, and the electric reheat is just to fine
tune the temperature of zones experiencing different loads or so...<br>
<br>
I played with all values but I can't figure out the pattern. I know that the
design temperature of the zones is 70F, and that the temperature that is
supplied to the zone should be 30 degrees higher than the zone temperature
(70+30=100F).<br>
<br>
Any advice on how to choose the "reheat delta temp" and the "hot
deck maximum supply temp" is greatly appreciated.<br>
<br>
Many thanks,<br>
Omar<br>
<br>
<br>
___________________________<br>
<br>
Omar Katanani<br>
Sustainable Design Engineer<br>
Email: omar@ecoconsulting.net<br>
<br>
<br>
EcoConsulting (Lebanon)<br>
Nahas Building, 4th floor<br>
4 St-Maron Street / Georges Haddad Avenue<br>
Postal Code: 2028 5806 SAIFI<br>
Beirut, Lebanon<br>
Tel: +961 (0) 1 971 255<br>
Mobile: +961 (0) 3 045 045<br>
<br>
<br>
EcoConsulting (UK) Ltd<br>
28 Marshalsea Road<br>
London, SE1 1HF<br>
Tel: +44 (0)207 939 0989<br>
Fax: +44 (0)207 939 0981<br>
Website: www.ecoconsulting.net<br>
<br>
</span></font></p>
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