<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML xmlns:ns0 = "http://schemas.microsoft.com/sharepoint/soap/workflow/"
xmlns:ns1 = "http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:ns2 = "http://schemas.microsoft.com/office/2004/12/omml" xmlns:ns3 =
"http://schemas.openxmlformats.org/package/2006/relationships" xmlns:ns4 =
"http://schemas.microsoft.com/exchange/services/2006/types" xmlns:ns5 =
"http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:ns6 =
"urn:schemas-microsoft-com:"><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2800.1615" name=GENERATOR>
<STYLE>@font-face {
font-family: Wingdings;
}
@font-face {
font-family: Garamond;
}
@font-face {
font-family: Arial Narrow;
}
@font-face {
font-family: Calibri;
}
@page Section1 {size: 8.5in 11.0in; margin: 1.0in 1.0in 1.0in 1.0in; }
A:link {
mso-style-priority: 99
}
SPAN.MSOHYPERLINK {
mso-style-priority: 99
}
A:visited {
mso-style-priority: 99
}
SPAN.MSOHYPERLINKFOLLOWED {
mso-style-priority: 99
}
P {
mso-style-priority: 99
}
P.MsoNormal {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
LI.MsoNormal {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
DIV.MsoNormal {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
H1 {
FONT-WEIGHT: bold; FONT-SIZE: 16pt; MARGIN: 12pt 0in 3pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
H3 {
FONT-WEIGHT: normal; FONT-SIZE: 12pt; MARGIN: 6pt 0in 0pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.5pt
}
A:link {
COLOR: blue; TEXT-DECORATION: underline
}
SPAN.MsoHyperlink {
COLOR: blue; TEXT-DECORATION: underline
}
A:visited {
COLOR: purple; TEXT-DECORATION: underline
}
SPAN.MsoHyperlinkFollowed {
COLOR: purple; TEXT-DECORATION: underline
}
P {
FONT-SIZE: 12pt; MARGIN-LEFT: 0in; MARGIN-RIGHT: 0in; FONT-FAMILY: "Times New Roman"
}
P.alist {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.15in; FONT-FAMILY: "Times New Roman"
}
LI.alist {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.15in; FONT-FAMILY: "Times New Roman"
}
DIV.alist {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.15in; FONT-FAMILY: "Times New Roman"
}
P.ahead3 {
FONT-SIZE: 12pt; MARGIN: 6pt 0in 0pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.5pt
}
LI.ahead3 {
FONT-SIZE: 12pt; MARGIN: 6pt 0in 0pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.5pt
}
DIV.ahead3 {
FONT-SIZE: 12pt; MARGIN: 6pt 0in 0pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.5pt
}
P.StyleaparaJustifiedAfter0pt {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Arial Narrow"; TEXT-ALIGN: justify
}
LI.StyleaparaJustifiedAfter0pt {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Arial Narrow"; TEXT-ALIGN: justify
}
DIV.StyleaparaJustifiedAfter0pt {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Arial Narrow"; TEXT-ALIGN: justify
}
P.alistnead {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial
}
LI.alistnead {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial
}
DIV.alistnead {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial
}
P.anumlist {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
LI.anumlist {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
DIV.anumlist {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: "Times New Roman"
}
P.aHead1 {
FONT-WEIGHT: bold; FONT-SIZE: 16pt; MARGIN: 0in 0in 6pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.25pt; TEXT-ALIGN: center
}
LI.aHead1 {
FONT-WEIGHT: bold; FONT-SIZE: 16pt; MARGIN: 0in 0in 6pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.25pt; TEXT-ALIGN: center
}
DIV.aHead1 {
FONT-WEIGHT: bold; FONT-SIZE: 16pt; MARGIN: 0in 0in 6pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.25pt; TEXT-ALIGN: center
}
P.StyleHeading3Left0Firstline0 {
FONT-SIZE: 12pt; MARGIN: 6pt 0in 0pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.5pt
}
LI.StyleHeading3Left0Firstline0 {
FONT-SIZE: 12pt; MARGIN: 6pt 0in 0pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.5pt
}
DIV.StyleHeading3Left0Firstline0 {
FONT-SIZE: 12pt; MARGIN: 6pt 0in 0pt; FONT-FAMILY: Arial; LETTER-SPACING: -0.5pt
}
P.a-text {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Garamond; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
LI.a-text {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Garamond; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
DIV.a-text {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Garamond; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
P.apara {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.35in; FONT-FAMILY: "Times New Roman"
}
LI.apara {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.35in; FONT-FAMILY: "Times New Roman"
}
DIV.apara {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.35in; FONT-FAMILY: "Times New Roman"
}
P.StyleHeading1Centered {
FONT-WEIGHT: bold; FONT-SIZE: 16pt; MARGIN: 0in 0in 6pt 0.5in; FONT-FAMILY: Arial; LETTER-SPACING: -0.25pt; TEXT-ALIGN: center
}
LI.StyleHeading1Centered {
FONT-WEIGHT: bold; FONT-SIZE: 16pt; MARGIN: 0in 0in 6pt 0.5in; FONT-FAMILY: Arial; LETTER-SPACING: -0.25pt; TEXT-ALIGN: center
}
DIV.StyleHeading1Centered {
FONT-WEIGHT: bold; FONT-SIZE: 16pt; MARGIN: 0in 0in 6pt 0.5in; FONT-FAMILY: Arial; LETTER-SPACING: -0.25pt; TEXT-ALIGN: center
}
P.Styleapara1TimesNewRomanFirstline025 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.25in; FONT-FAMILY: "Times New Roman"; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
LI.Styleapara1TimesNewRomanFirstline025 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.25in; FONT-FAMILY: "Times New Roman"; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
DIV.Styleapara1TimesNewRomanFirstline025 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; TEXT-INDENT: 0.25in; FONT-FAMILY: "Times New Roman"; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
P.PPAhead {
FONT-SIZE: 16pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial
}
LI.PPAhead {
FONT-SIZE: 16pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial
}
DIV.PPAhead {
FONT-SIZE: 16pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Arial
}
P.aparabullet {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.25in; FONT-FAMILY: "Times New Roman"; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
LI.aparabullet {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.25in; FONT-FAMILY: "Times New Roman"; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
DIV.aparabullet {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 0.5in; TEXT-INDENT: -0.25in; FONT-FAMILY: "Times New Roman"; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
P.AAbulllist1 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Garamond; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
LI.AAbulllist1 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Garamond; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
DIV.AAbulllist1 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt; FONT-FAMILY: Garamond; LETTER-SPACING: -0.25pt; TEXT-ALIGN: justify
}
P.AAbulllist2 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 1in; TEXT-INDENT: -0.25in; FONT-FAMILY: "Times New Roman"
}
LI.AAbulllist2 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 1in; TEXT-INDENT: -0.25in; FONT-FAMILY: "Times New Roman"
}
DIV.AAbulllist2 {
FONT-SIZE: 12pt; MARGIN: 0in 0in 0pt 1in; TEXT-INDENT: -0.25in; FONT-FAMILY: "Times New Roman"
}
SPAN.EmailStyle33 {
COLOR: #1f497d; FONT-FAMILY: Calibri
}
SPAN.EmailStyle34 {
COLOR: black
}
DIV.Section1 {
page: Section1
}
OL {
MARGIN-BOTTOM: 0in
}
UL {
MARGIN-BOTTOM: 0in
}
</STYLE>
</HEAD>
<BODY lang=EN-US vLink=purple link=blue bgColor=white>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Hi Peter, Darryl, Dean, et al,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>You have good info in searching for a
tankless machine that is a temperature modulated machine. In the old days
of only natural draft tankless you could choose between flow modulated and
temperature modulated (and perhaps other mechanisms of which I am not aware).
Today, while there are still natural draft tankless water heaters
readily available which exhibit, in the words of one of the
manufacturers, "mission critical reliability", the larger
capacity units are primarily power vented tankless water heaters. All of
the "big five" in the tankless arena that market to North America (Bosch,
Noritz, Rinnai, Paloma, and Takagi) offer power vented machines. IMHO, the
only commonality between natural draft tankless and power vented tankless are
they both use gas as a fuel source. Full stop. Venting and the requirement
for electric power are the biggest differences.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>To the best of my knowledge, all current
production power vented machines utilize an inlet water temperature sensor
(as well as an outlet water temperature sensor) and would therefore be suitable
for use with preheated water. The rub comes when your preheat water only needs a
bit more heat. Since none of the tankless available today can modulate to zero
there is a (sometimes) noticeable step when the "backup" tankless heater
adds it's minimum contribution. Since both the Vaughn Sepco and
Rheem/Ruud heat exchange tanks both offer electric elements as standard (no
additional cost) as do off-the-shelf electric tank water heaters,
the use of the electric elements as backup did not cost you any more in initial
expense. Unfortunately, when the preheat isn't sufficient you are using electric
to heat the entire (usually large) tank and you are blessed with
standby losses that are costing you out of pocket money. The tankless and
preheat are really a perfect match in so far as heating only when (and as
much as) necessary albeit the step or perhaps better described as the
stumble when/if only a bit of additional heat is necessary and the obvious
detractor - the cost of the tankless when the electric tank elements
are already in place. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>A high turn down ratio is commendable but the
absolute low end of burner performance is perhaps one way to choose
preheat backup tankless. The use of code compatible thermostatic mixing
valve(s) (e.g. Honeywell AM-1 series) is one more practical tool. The more stuff
that goes into the system, the more possibility there is for a failure.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>One aspect of the tankless that all too often is
overlooked is the opportunity to put the machine close to the load. If you have
widely separated loads then one solution is to put in two
smaller machines-one close to each load. Thereby eliminating the wait
or need for any recirc system. The practice of putting the new power vented
tankless where the old tank was or on the inside of an outside wall (in freezing
climates) simply to minimize the venting issues demonstrates to me a
lack of good design/planning/understanding.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Apologies for the tardy reply.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Caveat emptor, YMMV, Sincerely,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Bill Loesch<BR>Solar 1 - Saint Louis
Solar<BR></FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=peter.parrish@calsolareng.com
href="mailto:peter.parrish@calsolareng.com">Peter Parrish</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=re-wrenches@lists.re-wrenches.org
href="mailto:re-wrenches@lists.re-wrenches.org">'RE-wrenches'</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, December 07, 2008 5:02
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [RE-wrenches] SDHW and Tankless
Heaters</DIV>
<DIV><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face="Times New Roman" color=black size=3><SPAN
style="FONT-SIZE: 12pt; COLOR: black">We do a few SDHW systems and only for
customers that purchase a PV system from us and want SDHW as well. We want to
recommend a tankless heater where it makes sense (very old gas hot water
heater or we need the space to swap out the existing gas water heater for the
solar storage tank, new construction, etc.).</SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" color=black size=3><SPAN
style="FONT-SIZE: 12pt; COLOR: black"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face="Times New Roman" color=black size=3><SPAN
style="FONT-SIZE: 12pt; COLOR: black">I went to a seminar on the subject a few
years ago and one of the key issues was choosing a tankless heater that
“modulates on input water temperature”. The only one I was aware of at the
time was a small Bosch system with ˝ Cu lines. Are there big fellows that
“modulates on input water temperature” and could someone recommend one?
</SPAN></FONT></P>
<P class=MsoNormal><FONT face="Times New Roman" color=black size=3><SPAN
style="FONT-SIZE: 12pt; COLOR: black"></SPAN></FONT> </P>
<P class=MsoNormal><FONT face="Times New Roman" color=black size=3><SPAN
style="FONT-SIZE: 12pt; COLOR: black">- Peter</SPAN></FONT></P>
<DIV>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Peter T. Parrish,
President<BR>California Solar Engineering, Inc.<BR>820 Cynthia Ave., Los
Angeles, CA 90065<BR>Ph 323-258-8883, Mobile 323-839-6108, Fax
323-258-8885<BR>CA Lic. 854779, NABCEP Cert.
031806-26<BR>peter.parrish@calsolareng.com</SPAN></FONT><FONT face=Arial
color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">
</SPAN></FONT></P></DIV></DIV>
<P>
<HR>
<P></P>_______________________________________________<BR>List sponsored by
Home Power magazine<BR><BR>List Address:
RE-wrenches@lists.re-wrenches.org<BR><BR>Options &
settings:<BR>http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org<BR><BR>List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org<BR><BR>List
rules & etiquette:<BR>www.re-wrenches.org/etiquette.htm<BR><BR>Check out
participant bios:<BR>www.members.re-wrenches.org<BR><BR>
<P>
<HR>
<P></P>No virus found in this incoming message.<BR>Checked by AVG.
<BR>Version: 7.5.552 / Virus Database: 270.9.15/1837 - Release Date: 12/8/2008
9:38 AM<BR></BLOCKQUOTE></BODY></HTML>