These units were tested thoroughly by the University of Waterloo and
the Goodlife Fitness chain. They post quite impressive results and
stats online. Very thorough and very impressed with them.
No personal experience.

"Doctor Drivel" wrote in message
reenews.net...

"daestrom" wrote in message
...

"Derek Broughton" wrote in message
...
Ron Purvis wrote:

I think you are off on your figures. According to
http://www.fsec.ucf.edu/solar/apps/sdhw/dhwsave.htm the typical
home
uses
20 gallons of hot water per day for the first two persons and 15
gallons
of hot water for each additional person. That would be 25,550
gallons of
hot water per year for a family of four.

OK, I'll accept those numbers. Anyone got a better figure on the
average
cost of heating water? My numbers for heat required are, if
anything, on
the low side, but at $25/million BTU, and only 25,000 gallons per
year,
you're talking $250/year (somebody else said $20/month, so same
ballpark).
Still plenty to make a commercial solar water heater pay off.


I cut my DHW heating by somewhere between 1/3 and 1/2 by
installing a
waste-water heat-exchanger. Running hot water for a shower and
letting
all the energy go down the drain (literally), just doesn't make
sense. Of
course, this system only recovers heat from *running* water, so
baths and
dish washing doesn't affect it.

I have one of the largest units and it is a two-pass type so is
not the
most efficient model they have. Mine cost only about $270, did
the
installation myself.

http://www.gfxtechnology.com/

What was the payback period?