<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
<font size="+1">A caution to the maximum storage temperature for hot
water. Legionella bacteria show no growth above 135F/57C. A
140F/60C tank setting can leave portions of the water system at
risk of contamination. In electric water heaters with a 60C
setting 40% of heaters remained contaminated in one study. This
is at the heat source, what about further down the lines?
Multi-unit or multi story apartments. This contamination is not
typically found in gas or oil fired units set at 140, but their
lines are still susceptible to contamination. 140 should be
treated as the minimum storage temperature. Scalding is
definitely a problem but care is required to address both problems
in the building you are designing. With larger buildings I will
start at 160 at the tank and then start looking at the whole
system design. WHO recommends the tap temperature to be 120F, so
to a designer that is the furthest outlet.<br>
<a class="moz-txt-link-freetext" href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2094925/">http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2094925/</a><br>
Bruce Easterbrook P.Eng.<br>
Abode Engineering<br>
</font><br>
On 02/06/2011 02:39 PM, Carol Gardner wrote:
<blockquote
cite="mid:BANLkTi=2DE=8+i7QKPdweGPpQR+W_A9cBQ@mail.gmail.com"
type="cite">Thanks, Aaron, for providing much more detail than me.
You have covered it very well. For inlet cold water temperatures I
have always seen 50-55 F provided as the average temp: it may be
hotter in the summer and colder in the winter but overall I think
those work. <br>
<br>
Carol<br>
<br>
<div class="gmail_quote">On Thu, Jun 2, 2011 at 11:17 AM,
Dahlstrom, Aaron <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:ADahlstrom@in-posse.com">ADahlstrom@in-posse.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-US">
<div>
<p class="MsoNormal"><span>Tai:</span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal"><span>In general, I tend to follow
the procedure laid out in WEc3 for the hot water
savings from low-flow fixtures. I’ve found their
calculation procedure for total flow (gallons / year)
to be accepted by LEED reviewers.</span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal"><span>This does not address water
flow from fixtures outside the WEc3 scope, like
service sinks, so the ASHRAE handbook or a reasonably
documented project-specific assumption sounds like the
way to go to get total water use per year for these
fixtures.</span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal"><span>Like you mentioned, this also
does not specify the water temperatures, which are
needed for the calc. </span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal">
<span>Different hot water uses in a building often have
different temperature needs (ie handwashing,
dishwashing, showers, etc), so even if we know the
total water use for each of these fixtures, we’d need
to get the expected discharge temperature of each use
in order to figure out how much hot water is required.</span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal"><span>Most of the time I get the
temperatures I need from the project plumbing
engineer, who has a better familiarity with these
targets than I do.</span></p>
<p class="MsoNormal">
<span> </span></p>
<p class="MsoNormal"><span>If you don’t have access to a
plumbing engineer – </span></p>
<p><span><span>-<span style="font: 7pt "Times New
Roman";"> </span></span></span><span>For
the inlet cold water temp, per the eQUEST dictionary,
if you don’t specify the temp eQUEST uses the monthly
average ground temp. I hope this would be available
via an hourly report, although I haven’t checked.</span></p>
<p><span><span>-<span style="font: 7pt "Times New
Roman";"> </span></span></span><span>For
the discharge hot water temp, various plumbing codes
(IPC, NPC) specify limits on the hot water temp to
prevent scalding, and I’ve seen engineers take a
factor off of that to estimate the average hot water
use temp. I’ve heard 110 deg F for showers and 105 deg
F for lavs in our office. Service sinks might have
something higher (say 120?).</span></p>
<p><span><span>-<span style="font: 7pt "Times New
Roman";"> </span></span></span><span>For
the water storage temp, this is also something that
should be obtainable from the plumbing engineer. As a
starting point I’ve heard 120 – 140 deg F in our
office as well. I believe the IPC limits the maximum
storage water temp to 140.</span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal"><span>This should enable you to
calculate the quantity (gal / year) of hot water
leaving the water heater to serve the annual total
flow needed.</span></p>
<p class="MsoNormal">
<span> </span></p>
<p class="MsoNormal"><span>Finally, you need to turn the
gallons HW / year into a GPM PROCESS-FLOW, if you’re
inputting into eQUEST. One way to do this is to take
whatever use-schedule you had been using (ie eQUEST’s
default, ASHRAE 90.1-2007 User Manual’s, or
project-specific) and integrate it, to determine the
annual total equivalent full load hours. Dividing
total annual gallons by annual full-load hours (and
converting units), you should be able to arrive at a
GPM to enter as a process flow.</span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal"><span>Yours,</span></p>
<p class="MsoNormal"><span> </span></p>
<p class="MsoNormal" style="line-height: 150%;"><b><span
style="font-size: 9pt; line-height: 150%; color:
gray;">Aaron Dahlstrom , PE, LEED® AP</span></b><span
style="font-size: 11pt; line-height: 150%;"></span></p>
<p class="MsoNormal" style="line-height: 150%;"><b><span
style="font-size: 11pt; line-height: 150%; color:
rgb(23, 54, 93);">In P</span></b><b><span
style="font-size: 11pt; line-height: 150%; color:
rgb(97, 148, 40);">o</span></b><b><span
style="font-size: 11pt; line-height: 150%; color:
rgb(23, 54, 93);">sse</span></b><span
style="font-size: 9pt; line-height: 150%; color:
gray;"> – </span><span style="font-size: 8pt;
line-height: 150%; color: gray;">A subsidiary of</span><span
style="font-size: 9pt; line-height: 150%; color:
gray;"> </span><b><span style="font-size: 9pt;
line-height: 150%; color: rgb(204, 0, 0);">AKF</span></b><span
style="font-size: 9pt; line-height: 150%; color:
gray;">| 1500 Walnut Street, Suite 1414, Philadelphia,
PA 19102 </span><span style="font-size: 11pt;
line-height: 150%;"></span></p>
<p class="MsoNormal" style="line-height: 150%;"><span
style="font-size: 9pt; line-height: 150%; color:
gray;">d: <a moz-do-not-send="true"
href="tel:215-282-6753" value="+12152826753"
target="_blank">215-282-6753</a>| m: <a
moz-do-not-send="true" href="tel:267-507-5470"
value="+12675075470" target="_blank">267-507-5470</a>|
In Posse: <a moz-do-not-send="true"
href="tel:215-282-6800" value="+12152826800"
target="_blank">215-282-6800</a>| AKF: <a
moz-do-not-send="true" href="tel:215-735-7290"
value="+12157357290" target="_blank">215-735-7290</a></span><span
style="font-size: 11pt; line-height: 150%;"></span></p>
<p class="MsoNormal" style=""><span style="font-size: 9pt;
color: gray;">e: <a moz-do-not-send="true"
href="mailto:ADahlstrom@in-posse.com"
target="_blank">ADahlstrom@in-posse.com</a> | in
posse web: <a moz-do-not-send="true"
href="http://www.in-posse.com/" target="_blank"><span
style="color: blue;">www.in-posse.com</span></a> |
akf web: <a moz-do-not-send="true"
href="http://www.akfgroup.com/" target="_blank"><span
style="color: blue;">www.akfgroup.com</span></a></span><span
style="font-size: 11pt;"></span></p>
<p class="MsoNormal" style=""><span style="font-size: 9pt;
color: gray;"> </span><span style="font-size: 11pt;"></span></p>
<p class="MsoNormal" style=""><span style="font-size: 9pt;
color: gray;"> </span><span style="font-size: 11pt;"></span></p>
<p class="MsoNormal"><span style="font-size: 9pt; color:
gray;"> </span><span></span></p>
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span
style="font-size: 10pt;"> <a moz-do-not-send="true"
href="mailto:equest-users-bounces@lists.onebuilding.org"
target="_blank">equest-users-bounces@lists.onebuilding.org</a>
[mailto:<a moz-do-not-send="true"
href="mailto:equest-users-bounces@lists.onebuilding.org"
target="_blank">equest-users-bounces@lists.onebuilding.org</a>]
<b>On Behalf Of </b>Tai Lieu<br>
<b>Sent:</b> Wednesday, June 01, 2011 11:20 AM<br>
<b>To:</b> <a moz-do-not-send="true"
href="mailto:equest-users@lists.onebuilding.org"
target="_blank">equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> [Equest-users] DHW Savings LEED NC 2.2</span></p>
<div>
<div class="h5">
<p class="MsoNormal"> </p>
<p class="MsoNormal">Hello All<br>
<br>
We're being audited on the energy model for the dhw
saving. I'm just wondering if this make sense and
from your experience if it would be acceptable to
the LEED reviewer.<br>
<br>
What I've done is taken numbers from ASHRAE Handbook
HVAC Applications DHW consumption per fixture for
office use.<br>
7.6 L / hr for lavatory fixtures<br>
<br>
Showers, kitchen sinks, and Lavatory sinks.<br>
Service sinks I'm not quite sure whether i should
include all 5 service sinks (one on each level) or
just one sinks since there won't be any mopping done
since most of the building Under floor air
distribution and i'll do a write up of course to
explain my reasoning.<br>
<br>
I took the consumptions per fixture numbers
multiplied by the amount of fixture then by the
demand factor given.<br>
<br>
7.6 L/h x 55 # of fixtures x 0.3 demand factor<br>
<br>
for each type i took the savings percentage based on
each fixture. So baseline is 2.5 and proposed case
is .5 for lavatory fixtures<br>
<br>
.5 proposed case / 2.5 base case<br>
<br>
So the proposed domestic hot water demand is 25.08 L
/ hr or 0.11 gpm.<br>
<br>
The reviewer had asked for percentage of hot water
vs cold water, and temperature at the fixtures, i
found that harder to substantiate. So I thought
this process would be a lot better.<br clear="all">
<br>
Tai Lieu</p>
</div>
</div>
</div>
<br clear="all">
This e-mail may contain information that is confidential,
privileged or otherwise protected from disclosure. If you
are not an intended recipient of this e-mail, do not
duplicate or redistribute it by any means. Please delete it
and any attachments and notify the sender that you have
received it in error. Unintended recipients are prohibited
from taking action on the basis of information in this
e-mail. E-mail messages may contain computer viruses or
other defects, may not be accurately replicated on other
systems, or may be intercepted, deleted or interfered
without the knowledge of the sender or the intended
recipient. If you are not comfortable with the risks
associated with e-mail messages, you may decide not to use
e-mail to communicate with In Posse.
</div>
<br>
_______________________________________________<br>
Equest-users mailing list<br>
<a moz-do-not-send="true"
href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org"
target="_blank">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a><br>
To unsubscribe from this mailing list send a blank message to
<a moz-do-not-send="true"
href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</a><br>
<br>
</blockquote>
</div>
<br>
<br clear="all">
<br>
-- <br>
Carol Gardner PE<br>
<style type="text/css">#avg_ls_inline_popup{position: absolute;z-index: 9999;padding: 0px 0px;margin-left: 0px;margin-top: 0px;overflow: hidden;word-wrap: break-word;color: black;font-size: 10px;text-align: left;line-height: 130%;}</style>
<pre wrap="">
<fieldset class="mimeAttachmentHeader"></fieldset>
_______________________________________________
Equest-users mailing list
<a class="moz-txt-link-freetext" href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</a>
To unsubscribe from this mailing list send a blank message to <a class="moz-txt-link-abbreviated" href="mailto:EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</a>
</pre>
</blockquote>
</body>
</html>