Originally Posted by zootjeff
In theory this does work. People warn about minerals in the water eating away at the coils. Some AC units actually pump the water from the indoor coil to a pool of water under the outdoor coil do do this very thing and benefit from the evap cooling. Every window based unit does this, so why not do it on your central AC unit?.. It does help some, if it's worth it or not is a judgment call. Here is a company that sells kits for this:
While the condensate from an evap coil is dirty. It does not contain the minerals that water does from your faucet/house piping. So comparing the 2 is not an apples to apples comparison.
The coolnsave is not as great of a thing as many think. And quite a few people have paid for the damage their water has done to the condenser coil. In the way of either higher cost to clean the coil, higher electric bills as the extra minerals coat/closed off the air flow, or caused leaks.
They work ok in some areas, not in others, so people should be aware that they should regularly(weekly) inspect their condenser if they decide to use one of those misters.
For condensers set on large concrete areas. Simply keeping the concrete wet/damp will lower the air temp draw into the condenser, and leave n o deposits on the condenser.