ok, so I'm only 6 months late on this discussion, better late than
never...
The HVAC guys here are correct in that there are off the shelf
solutions and that they're relatively expensive. However, what you're
looking for isn't all that bad.
You've got desuperheaters designed to be spliced into A/C systems of
the size common in home use, such as:
http://www.packless.com/desuper/desuper.html
and you've got parts like:
http://www.doucetteindustries.com/desuperheater.html
see the docs which diagram the entire thing:
http://www.doucetteindustries.com/ac_desuperheater.pdf
also, see: (geothermal based hot water)
http://www.hydrodelta.com/images/brochures/Magnum.pdf
That gets you a water cooled assist/heat extractor for your A/C.
Research indicates that you have the benefit of increasing your A/C
efficiency by 5%-10% or considerably more. By extracting the heat from
your coils, your A/C doesn't have to work as hard, extending its life
and increasing its efficiency.
see also
http://www.osti.gov/energycitations/...sti_id=5308598
You've also got the geothermal companies selling high priced
desuperheater units. As others have mentioned see Florida Heat Pump,
WaterFurnace, ECR tech. for examples.
http://www.ecrtech.com/content/inter...rheating.ht m
http://www.waterfurnace.com/watertowater.asp
An experienced A/C tech would be able to install the desuperheater for
you. Don't try this at home since you have to splice into the
refrigerant lines.
As others have noted, you now have to get the pool water to the
desuperheater without eating it up. Again, that isn't a big deal. Every
pool heater sold has a heat exchanger that circulates chlorinated water
without self-destructing.
Circulate the heated water/antifreeze from the desuperheater in a
closed loop through a heat exchanger. Circulate the pool water through
that heat exchanger. All your loops are closed and the nasty chemicals
kept where they won't damage the expensive stuff. If you have to
replace the heat exchanger, it's just a heat exchanger. If you don't
want to worry about corrosion, then get a titanium heat exchanger meant
for high chlorine pool use. Unfortunately the heat transfer
characteristics of SS and Ti are relatively poor, so often
copper-nickel (cupro-nickel) is used as long as you aren't going to use
TOO high chlorine levels.
see:
http://www.heatexchangersonline.com/poolheaters.htm
As for being super expensive, people use that vague term but don't
define what it means. Well, here's one concrete example for one
component:
http://www.southern-dist.com/Pricelist.html
Desuperheater - $465
You need to add the circulation pump and labor to the equation. Even if
the desuperheater complete system costs you a couple $k to make, the
payback would only take a couple years not including the cost savings
from improving the efficiency of the A/C unit. The thing to keep in
mind is that complete standalone packages are expensive because in
manufacturing, one typically uses a 4x-6x multiplier to figure sales
price from parts costs. If a commercial unit runs a few grand, then the
wholesale parts costs will be ~$750. So, if you can get the parts,
maybe they'd cost you $1500 (allowing for 50% wholesale discount).
Then again, you could save all the playing around, forget the idea of
heating using waste heat, and buy a normal heat pump for your pool for
$3k... depends how much of a geek you are (spoken from a true geek who
would spend several weeks playing with something to learn how its done)
Best of luck.
By the way, if you actually tried something out already, let us know!
Richard J Kinch wrote:
Pumbaa writes:
In general I seem to be getting a lot of
cautious/negative feedback on the idea. BUT, I have not heard one
thing
from someone who HAS actually tried to do this. It makes me
wonder, how
come nobody thinks it will work when nobody has even tried.
Look, it's been tried. It works. But not cost-effective. More
complex,
more expense. Forget it.