[RE-wrenches] SHW - parallel tanks

[Solar Energy Solutions]

For years we installed, "Double Whammy" bypass valves enabling folk to go 'solar only', 'solar preheat', or 'primary only', hoping folk would bypass and turn off their primaries during the summer season.  We did this ourselves for years.  However, going back on those 'DW' systems years later and asking the owners if any of them ever, ever used them even after having paid for them... and the answer was always, 'no'.    Like Jeremy says, just turn off the primary and the boiling hot water from the solar tank should keep the primary tank nice and hot.  
 
In the mean time we have moved to a 120 gallon Rheem single tank DB system with a steca controller and a digital Intermatic timer that only turns the heater on for an hour twice a day in the winter and is kept off all summer long.
 
Smiles,
 
Andrew Koyaanisqatsi 
President 
Solar Energy Solutions, Inc. 
Since 1987, 
Moving Portland and Beyond  
to an Environmentally Sustainable Future.  
503-238-4502 
http://www.solarenergyoregon.com/  
  
"Better one's House too little one day 
than too big all the Year after." 
  
 

________________________________
 From: Kirk Herander <kirk at vtsolar.com>
To: RE-wrenches <re-wrenches at lists.re-wrenches.org> 
Sent: Tuesday, September 24, 2013 3:19 PM
Subject: [RE-wrenches] SHW - parallel tanks
  


Hi,
 
Every summer I get a few calls from annoyed hot water customers who can’t stand hearing their boiler fire merely to keep the indirect tank up to setpoint temperature, when of course the solar preheat tank is at 160 degrees or better at mid-day. So what’s the best way to transfer heat, in essence temporarily putting the tanks in parallel, from the solar tank to indirect? I can think of a few possibilities using a circulator and temperature controller, and a additional connection between the tanks, such as the tank drains plumbed together as a return line, but where is the best place to locate the circulator in a standard preheat arrangement (i.e. hot output of solar preheat plumbed to cold input of indirect tank)?
 
Kirk Herander
VT Solar, LLC
dba Vermont Solar Engineering
NABCEPTM Certified Inaugural Certificant
NYSERDA-eligible Installer
VT RE Incentive Program Partner
802.863.1202
 
_______________________________________________
List sponsored by Home Power magazine

List Address: RE-wrenches at lists.re-wrenches.org

Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out participant bios:
www.members.re-wrenches.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20130924/e79e0848/attachment-0004.html>