[Greenbuilding] Solar Water Heater architecture

[Corwyn]

On Aug 13, 2006, at 08:22, Lawrence Lile wrote:
> Getting ready to install a solar water heater in new construction, and 
> have been agonizing about the arrangement.

Lawrence,

Here is my current plan (not done yet so take with a grain of salt).  
Water panels on the standing seam roof, mounted with S-5 connectors.  
Propylene glycol (with water, and neon colorant (to detect leaks)) in a 
loop to the tank.  Probably an El-Sid or similar PV pump.  Large site 
built 500 gallon non-pressurized tank in the basement (possibly wood 
lined with glass).  Tank holds plain water (with a different highly 
visible colorant).  I am hoping that I will be able to detect a leak 
from solar loop to tank, or tank to water supply.  More coils of copper 
tube to pre-heat DHW, and heat the thermal mass (possibly also a hot 
tub to deal with summer excess).  The solar loop should only have a few 
gallons, so that much glycol shouldn't break the bank.  Wouldn't catch 
me with ethylene glycol anywhere near my drinking water.

Open questions for me remain:
Can I get dyes that can be detected for both kinds of leaks?
Best method of building the tank (and ensuring that failures don't 
result in a flooded basement?
Control systems?  I would like to be able to control movement of heat 
based on tank temperature, house temperature, time of day, outdoor 
temperature, season, occupancy level (and probably some others I can't 
think of right now).
Cost?

Thank You Kindly,

Corwyn

-- 
Corwyn
Kermit didn't know the half of it...
http://www.greenfret.com/
corwyn at greenfret.com