alt.energy.homepower

On Mon, 23 Jul 2007 12:30:58 -0700, wmbjkREMOVE@ wrote:

>On Mon, 23 Jul 2007 18:40:56 -0000, Scott < @ >
>wrote:

>>Anyway, anyone have an idea of how cold the water should be to make a
>>cooling system viable in the summer?

I'm thinking that you could expect about a 10 degree F drop across the
coil. So if duct temperature is 75, you'd need water 65 or colder.

>>Source of a pump?

Once you figure out total head and gpm, check the curves of applicable
circulators. I expect the right one might only cost about $150.

>>Look into how high a pump can pull the water to get where my AC heat
>>exchanger is located. I anticipate the water would flow through there
>>to use the existing ductwork and fans. My home is not terribly far
>>horizontally or vertically from the lake (perhaps 8' vertical, and 40'
>>horizontal), but the AC equip is on the attic of second level, so that
>>would be a bit of a pump.

That height and distance is trivial.

>> I don't know if it makes more sense to have a
>>closed loop or open loop. Closed would not "muck up" as fast, the
>>lake water does have alge. Perhaps a copper coil would work and then
>>PVC or something like that to keep costs down on the rest of the
>>pipes.

Sure. Don't forget to allow for heat loss in the plumbing.

>>I have also an ample supply of southern sun, and have looked at PV
>>panels and a grid tied solar system, but w/o any significant tax
>>incentives the payback was not good enough, over 10 years. Maybe a
>>change in presidents for '08 will solve that problem.

No sense waiting for pandering politicians. Solar water heating is
relatively cheap, you could start there. A good DIYer can put together
a decent setup for about $1000. Heck, if the line feeding your water
heater was run through the attic during the warm season you'd get an
appreciable gain.

Wayne