next best thing to geothermal A/C

[oil pan 4]

We all know geothermal is the way to go for A/C. But if you dont have thousands of dollars to dig up your yard and lay pipe this could be the next best thing, depending on where you live.
I was considering useing some ducting and water mist injection on the condencer coils of a home A/C unit.
If you live some where the humity is 100% all the time it might not work so well. The water mist could collect on the condencer coils and leave behind hard water deposits (bad).
Now where I am the humity is around 25% or less most of the time, and swamp coolers can make the inside of the house sticky some times.
What I would do is set up a few feet of ducting leading to the inlet of the condencers just enough distance to evap the water, so any deposits act like dust more than anything.
I would build the mist system out of the biggest water mist injection nozzles (15gph@100psi) for vehicle applications and use a 12v surflo agro pump to boost up the pressure to about 60psi.
Turning the pump on and off would be easy, just have to use the power going to the condencer fan to flip a relay or use it to straight up power a transformer for the water pump.
Has any one tried anything like that?

[Daox]

Yep, its been done. I think they even sell kits to do it.

If you're real interested in home efficiency, I suggest you check out the EcoRenovator Forum. Its EcoModder's sister site for home efficiency. We even have a guy who is doing a DIY geothermal system. His target is to stay under $2k and he is doing it so far. He has the loop field in and is working on the heat pump itself.

[bikin' Ed]

I've seen on a home show, a similar item. It mounted to the top of the a/c unit, connected to a garden hose, had a large paddle, and used the airflow from the compressor fan to actuate the mister. I'm not sure, but I think it was This Old House.

So you weren't the first to think of it.... It still sounds like a good idea.

[JasonG]

The Carrier AirV unit has a ring around the fan blades.
The ring sits in the condensate and flings it through the condenser coil.
On all but the most humid of days, it uses all of the condensate this way.
Worked extra good as the condensate is free cooling (~40-50 deg F) and free water.

[oil pan 4]

Here is what I am thinking. Since sending water mist into the condencer coil is not a great idea (scale build up) it would require a tunnel to give the water time to fully evaporate. That would work great in NM. It would still be kind of bulky. As an alternative I was considering placing a mini swamp cooler forward of the condencer air stream. This would even work some what in humid climates, it wouldn't be highly effective but it would be a better option than water mist that would likely leave scale build up on the condencer.

Plus the swamp cooler rig could use waste water off the evaporator.
It would be cheaper than a geothermal unit and work on an existing house A/C unit.

I have seen little wind units that use condesate to help cool the condencer but they are still not very efficient. Its so dry in NM that there will never be enough water coming off the evaporator to give the condencer a steady supply of water.

I have seen a few very small almost like a personal swamp cooler for sale in northern tool or tractor supply. They would make a good starting point since they would have the water level control, pump and wetted media all rolled into one package.