for those of you driven outdoors by no power... you might consider a water misting hose.. they work pretty well down here, even in the high humidity... we use them with a pop up tent canopy for cross country runners...

I'd prefer a soak in a decent size kiddie pool myself (add ice as needed for maximum cooling effect), although no power often means no water (or ice) for a lot of people. We've been very fortunate and have not lost power in all the recent storms in our area, but it has flickered off and on too many times.

I have one of those wrapped around my air conditioning condenser and turn it on during the hottest part of the day when it's going to be one of those 90+ days.

Helps make the A/C more efficient.

(for those of us with power)

Interesting idea Unimogbert. Can you share more info, pictures?

Have you taken any measurements to support your theory? Any sort of anecdotal evidence to share? Not trying to be argumentative, I'm truly interested in your idea.

i worked as a security guard while going to school. one of the places i guarded it was the job of the guard to go turn off the sprinklers on the roof after the sun went down when it was hot because the A/C was unable to keep up with the load. the building engineer had rigged up a sprinkler on the coils to use when it was unusually warm.

sprinkling the coils is an ac condenser cure-all. lowers the microclimate temp in hot spells, melts the ice off and raises the temp in cold spell heat exchange mode: potential downside-scale buildup from hardwater.

learned discussion by engineers

All three of my window AC's use the outside blower fan to sprinkle water from condensation from the cold coils, up onto the hot coils, presumably to cool them.

Several people have answered since I posted.

I'm an Engineer (thus the 'bert' in my screen name). We learned about the latent heat of vaporization pretty early.

Water spray = cooler air = lower starting air temperature going into the condenser airflow = better thermal efficiency.

I don't know how much water it uses. I just turn the water faucet on a little so it's probably well under 1 gpm possibly in the range of 1 gph.

(Sorry. No pictures. I don't own a digital camera.)

I have done similarly with large scale industrial A/C, it undoubtedly works.
The electric power used by the compressor declined, but only slightly, AFAIR by a few %
The cooling output increased significantly, one could watch the chilled water temperature drop significantly.

The purpose of A/C is of course to remove heat, and the evaporation of water takes away a lot of heat.

Despite these gains it is probably not a good idea on a regular basis, as the water evaporates it leaves behind lime scale and other impurities, this fouls the condensor and reduces the efficiency in the long term.
Rainwater would be better than most city water or well water.

Take great care that water can not enter electrical parts, outdoor equipment is of course designed to withstand rain, but might be damaged by water sprayed sidewise and potentialy into places that rain can not reach.

I think I mixed 2 concepts - cooler intake air, and latent heat of vaporization. Both are at work on this rig.

Latent heat is the energy it takes to drive liquid water to vapor. It's why sweating works- it removes energy from the skin as the water evaporates.

I have a friend whose company builds a somewhat similar clever rig for commercial energy conservation. During the night, when electric rates are low, the system chills down a volume of water into ice. Then, during the heat of the day, the ice is used as the means to cool the A/C condensor thus greatly increasing effectiveness of the A/C system - at least as long as the ice lasts and the water stays cool.

There are definite issues with scale buildup and perhaps algae.
I see a little scale on my unit but with 5% humidity on 100F days and not running the water continuously, no algae can grow.