I live in Phoenix where summer outdoor temperatures regularly exceed 110°F and humidity around 15% or lower is not uncommon. In this environment a mist system can easily pull the temperature down 20 to 30 or even 40 degrees in some cases. I've been toying with the idea of cooling my outdoor AC unit using mist, and did a little research.
There are several commercially-available systems to do precisely this such as this industrial unit and this residential one. But I wanted to get an idea of what other people think of these systems. In particular, I'm interested in the long-term effects of using these systems, especially with respect to mineral build-up and corrosion. The vendors of the commercial systems claim to have these factors under control, but I'd rather hear it from a neutral POV.
I'm not particularly interested in unfounded FUD or enthusiasm, and comments like, "if it works so well then we'd all be using it" are particularly unhelpful. Instead, I would like to know how these units actually fare in real-world usage. Also, bear in mind that this is Phoenix, not New Orleans; in the dry summer heat nothing stays wet for more than a few seconds. Factors like mold are an absolute non-issue.
Best Answer
Mineral build-up is going to be dependent on your water. Do you have a Water Quality Report? Mine looks like this:
http://www.acwd.org/story_detail.php5?story_id=157
Hard water starts around 10 grains per gallon or 170 ppm. In other words, 1 liter of water will have 0.17 grams of calcium/magnesium. I didn't see any water usage estimates for coolnsave aside from 6 cents per day. Also, they sell a water treatment filter which could take some of the minerals out but there aren't any details provided.
The thermodynamics behind coolnsave are sound and the price is reasonable. Your best bet if no one here has any personal experience is to just try it yourself, keeping a daily inspection schedule for the first month to be sure you aren't coating your condenser with something that you can't remove.