Bill,
The water is quite hard (30 grains/gal), but there is a softener on
the DHW that lowers the CaCO3 level significantly. I thought that
this might have been a contributing factor with the previous mixing
valve, but replacement (~2 years ago) didn't address the problem.
Other than hardness minerals are quite low.
-Kelly
Kelly Keilwitz, P.E.
Whidbey Sun & Wind
Renewable Energy Systems
ke...@whidbeysunwind.com
360-678-7131
On May 19, 2010, at 6:26 AM, Bill Loesch wrote:
Hi Kelly,
Is water quality an issue in that location?
More than one tankless manufacturer lists max levels of all or some
of the
following:
pH - 6.5 - 8.5
TDS (Total Disolved Solids) - 500 ppm
Total hardness - 6 grains
Aluminium - 2.0 ppm
Chlorides -250 ppm
Copper - 10 ppm
Iron - 0.3 ppm
Manganese - 0.05 ppm
Zinc - 0.5 ppm
as qualifying for the addition of a water conditioner or softener.
In my experience, many folks, even with conditioning/softening
equipment
installed (oftentimes inop), are blissfully ignorant of the effects of
water quality until something stops the hot water.
I personally like Bob-O's approach of a warning label at the hot
faucet for
solar applications. The code officials in my neck of the woods do
not share
my enthusiasm for this approach.
Because here in STL, we additionally have a chloramine presence in
the water
this adds a requirement for specialty o-rings, etc. for control
items in the
water path.
Hope this helps,
Bill Loesch
Solar 1 - Saint Louis Solar
----- Original Message -----
From: "Kelly Keilwitz, Whidbey Sun & Wind" <ke...@whidbeysunwind.com>
To: "RE Wrenches listserve" <re-wrenches@lists.re-wrenches.org>
Sent: Wednesday, May 19, 2010 1:14 AM
Subject: [RE-wrenches] SWH - mixing valves
Thermal wrenches,
I'm having an ongoing issue with mixing valves in my own system not
keeping a steady mix domestic HW temperature as the tank temperature
varies with solar heating. If I set it for (say) 122˚F mix when the
tank is 135˚, it seems to hold that differential at all tank temps -
i.e. when the tank is hotter the mix is too hot (sometimes
dangerously
so), and when colder the mix is too cold for a comfortable shower.
Thus, I need to change the setting all the time.
I'm now using a Honeywell valve with a 90˚ - 145˚ range. This is a
replacement for a valve with a wider range that acted the same way.
Any ideas, suggestions for better valves, or....?
This has me wondering how many of our SWH customers are
experiencing a
similar thing, but just aren't bothered enough to say anything. We
seem to have encountered many plumbing situations where the mixing
valve allowed weird backflow or siphoning situations to mess with
system operation, especially with HW recirculation. I thought I had
all such causes eliminated on my system, but maybe not.
Thanks for sharing your experience with such matters.
-Kelly
Kelly Keilwitz, P.E.
Whidbey Sun & Wind
Renewable Energy Systems
ke...@whidbeysunwind.com
360-678-7131
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options & 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
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options & 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
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options & 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
