On Sat, 29 Mar 2008 07:19:16 -0700, "Bill" wrote:
"ransley" wrote in message
If you have the time get another tank, put it outside with bypass
valves, when nightime temps are above incomming water temp
let the tank fill, the sun will heat it fast
Actually for the summer, I am thinking about running a bunch of plastic
pipes in my attic which gets to be very hot. Plastic because I will need to
drain it each fall to prevent the pipes from freezing.
You'd probably be dollars ahead to simply get that heat out of your attic and reduce
the load on your AC.
Also with this idea, I am thinking of installing another insulated water
tank and using a solar powered pump to circulate water slowly from the
insulated tank through the attic pipes and back to the insulated tank.
Why would you waste money on an under-powered and over-priced solar pump that quits
working when the sun goes behind a cloud when a conventional pump works so well and
draws so little power?
Solar water heat from the roof works well but generally, the tubing itself needs to
be exposed to the solar radiation. Radiative energy transfer is much more effective
than convective in this situation.
I did a similar system on my restaurant's flat tar roof. I simply laid several
hundred feet of direct burial black PVC pipe directly onto the tar. I tried
industrial black garden hose before that but it wasn't sufficiently UV-resistant to
last very long.
On bright sunny days, the water would almost boil. In all cases when the sun was
shining, this system made all the hot water the restaurant needed. There was a
NG-fired tankless heater for other times, of course. This system used no tank and no
fancy plumbing. City water went in one end of the tubing and hot water came out the
other. A three-way valve let me quickly switch the solar heater in and out as
needed. All manual control which was good enough.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com -- best little blog on the net!
Tellico Plains, Occupied TN
I don't speak Stupid so do speak slowly.