<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p><font face="Verdana">This is what I cam<font face="Verdana">e up
with:</font></font></p>
<p><font face="Verdana"><font face="Verdana"></font>The calculation
is Q = mcp <font face="Verdana">delta T</font></font></p>
<p><font face="Verdana">Wat<font face="Verdana">er Temp out = 120</font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana">Water
Temp in = ground <font face="Verdana">source Temperature @
50F?</font></font></font></font></p>
<p><font face="Verdana">de<font face="Verdana">l<font face="Verdana">ta
T = 70<font face="Verdana">F</font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana">m = <font
face="Verdana">mass flow rate. ASHRAE is the source
fo<font face="Verdana">r this<font face="Verdana">. 20<font
face="Verdana">gals per person <font
face="Verdana">per day = 20 gallons x 8.34
lbs/gallon = 167lbs/day<font face="Verdana">/person</font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana">cp = 1
BTU/lb-degree F</font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana">Q = 167
<font face="Verdana">x 1 x 70 = 11,676
BTU/day<font face="Verdana">/person</font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana">Divide this <font
face="Verdana">by the eff<font
face="Verdana">iciency of the
water heating system (<font
face="Verdana">I'll assume =
.86) =11,676<font
face="Verdana">/.86 = 13,
577 BTU/person/day</font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana">convert to
kWh if necessarym 13,577<font
face="Verdana">/<font
face="Verdana">3412 =
~4 k<font
face="Verdana">Wh<font
face="Verdana">/person/day,
12<font
face="Verdana">0
kWh/month</font><br>
</font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana">I
checked this
again<font
face="Verdana">st
one month<font
face="Verdana">
<font
face="Verdana">and
it seems
reasonable. <br>
</font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana">Webs<font
face="Verdana">ite
assuming ~3<font
face="Verdana">.5
family size
comes up with
@ 400kWh per
month. <font
face="Verdana">T<font
face="Verdana">hey
approached it
a<font
face="Verdana">nother
way with
assuming run
times.</font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><a class="moz-txt-link-freetext" href="https://www.google.com/search?safe=active&source=hp&ei=Z3KqWvXiNsGb5wKJ2Kf4DA&q=electric+water+heater+use+annual+consumption&oq=electric+water+heater+use+annually&gs_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.0....0...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI">https://www.google.com/search?safe=active&source=hp&ei=Z3KqWvXiNsGb5wKJ2Kf4DA&q=electric+water+heater+use+annual+consumption&oq=electric+water+heater+use+annually&gs_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.0....0...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI</a></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><br>
</font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana">Chris</font><br>
</font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"><font
face="Verdana"></font></font></font></font></font></font></font></font></font></font></font></font></font><br>
</font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></font></p>
<p><font face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"><font
face="Verdana"><font face="Verdana"></font></font></font></font></font></font></font></font></font></font></font></font><br>
</p>
<br>
<div class="moz-cite-prefix">On 3/15/2018 8:09 AM, Mike Kocsmiersky
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:01b001d3bc56$809034a0$81b09de0$@net">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 12 (filtered
medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Helvetica;
panose-1:2 11 6 4 2 2 2 2 2 4;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="Section1">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Barton
makes a good point with regards to the incoming ground
water temperature and the amount of heat required to bring
it up to shower temp.
My recollection is that ASHRAE states 20gal/person/day for
the first 2 people,
then 15gpd or 12gpd thereafter. However those rates vary
wildly with
consumers, from those that never bathe to the high schooler
that needs 3
showers a day. In the northeast water heating can be up to
19% of the total
household energy load for the year. Also, I would recommend
the air source
heat pump water heaters if you have significant humidity or
an on demand unit.
Water tanks are typically under insulated and can lose
2kWh/day in standby
losses.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Mike
Kocsmiersky<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Principal<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Spirit
Solar Inc.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">(413)
734-1456<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<div style="border:none;border-top:solid #B5C4DF
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
Barton Churchill
[<a class="moz-txt-link-freetext" href="mailto:barton@solarips.com">mailto:barton@solarips.com</a>] <br>
<b>Sent:</b> Wednesday, March 14, 2018 7:31 PM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> Re: [RE-wrenches] Electric Water kWh/
person<o:p></o:p></span></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">You first need to know your ground
temperature. Then figure
a delta to 100 or so degrees. Most but not all showerheads
flow 2.5gpm and
showers are typically 10 minutes. You can then find a
calculator online to
calculate how many Btus are required to raise water temp for
your delta per gallon.
Convert to kWh, add some contingency and you should be good. <br>
<br>
On Wednesday, March 14, 2018, <<a
href="mailto:drake.chamberlin@redwoodalliance.org"
moz-do-not-send="true">drake.chamberlin@redwoodalliance.org</a>>
wrote:<o:p></o:p></p>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span
style="font-size:7.0pt;
font-family:"Helvetica","sans-serif"">Hello
Wrenches,<br>
<br>
Is there a good way to estimate the power that will be
consumed for electric
water per person per day? We are estimating the amount of
power that will be
used by an all electric duplex, and the water heater
amount seems high. The
current model we have claims 3493 kWh/ year per 26 gallon
tank will be
consumed. With the two units, that would add up to 6986
kWh / year for hot
water, pushing the system size to humongous for a 1300 ft
sq building. <br>
<br>
Does that seem high? There will be a maximum of 2 people
per unit. <br>
<br>
The owner is considering going to 115 V units with a 15
gallon tanks. I think
the smaller tank would help, but it would seem that the
amount of hot water
consumed would be the main issue. <br>
<br>
How can we get a good estimate for a per person energy
usage for electric hot
water? Any other suggestions are welcome.<br>
<br>
Thank you,<br>
<br>
Drake<br>
<br>
<o:p></o:p></span></p>
</div>
<p class="MsoNormal"><br>
<br>
-- <o:p></o:p></p>
<div>
<div>
<div>
<div>
<p class="MsoNormal"><span
style="font-size:7.5pt;color:#888888">-- </span><o:p></o:p></p>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<p class="MsoNormal"><span
style="font-size:7.5pt;font-family:"Arial","sans-serif";color:#666666">Barton
Churchill</span><span
style="font-size:7.5pt;font-family:
"Arial","sans-serif""><br>
<span style="color:#888888">406.587.5295
<br>
</span>2430 North 7th Bozeman,
MT 59715<br>
<span style="color:#FF9900"><a
href="http://www.solarips.com/" target="_blank" moz-do-not-send="true"><span
style="color:#1155CC">www.solarips.com</span></a></span></span><span
style="font-size:7.5pt"><o:p></o:p></span></p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div>
<p class="MsoNormal"><span style="border:solid
windowtext 1.0pt;padding:0in"><img
id="_x0000_i1025"
src="cid:part3.465B66DF.C08135B9@entech-engineering.com"
alt="Image removed by sender." class=""
height="100" width="100" border="0"></span><o:p></o:p></p>
</div>
</div>
</div>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
List sponsored by Redwood Alliance
List Address: <a class="moz-txt-link-abbreviated" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a>
Change listserver email address & settings:
<a class="moz-txt-link-freetext" href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a>
List-Archive: <a class="moz-txt-link-freetext" href="http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html">http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html</a>
List rules & etiquette:
<a class="moz-txt-link-abbreviated" href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a>
Check out or update participant bios:
<a class="moz-txt-link-abbreviated" href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a>
</pre>
</blockquote>
<br>
<div class="moz-signature">-- <br>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<div class="moz-signature"><br>
<div class="moz-signature">
<meta http-equiv="content-type" content="text/html;
charset=utf-8">
<div class="moz-signature">
<div class="moz-signature">
<div class="moz-signature">
<div class="moz-signature">
<div class="moz-signature">
<meta http-equiv="content-type" content="text/html;
charset=utf-8">
<font size="-1"> Christopher Warfel, PE<br>
ENTECH Engineering, Inc.<br>
PO Box 871, Block Island, RI 02807<br>
(401)466-8978</font><br>
<div class="moz-signature"> <br>
<meta http-equiv="content-type"
content="text/html; charset=utf-8">
<title></title>
<a href="http://entech-engineering.com"><img
moz-do-not-send="false"
src="cid:part4.D3168CCE.5720B6C8@entech-engineering.com"
alt="EEI logo" height="89" width="201"
border="0"></a> </div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>