While looking for products to sell for the Mapawatt OpenSky store, I found a pretty cool (no pun intended) product called Cool-N-Save. The product sends a spray of mist over your Air Conditioner's condenser coils, which helps the heat transfer between the coolant flowing through them (which removes heat from your home) and the outside air. Their website has a nice section on how it works. Even though I've seen a similar system in practice as Southface Institute here in Atlanta, I was slightly skeptical at first, until I saw that the Cool-N-Save has been studied by the Mechanical Engineering department at Tulane University! They advertise that the product can save up to 30% on cooling bills.
The result of the study basically says the Cool-N-Save works as advertised! It obviously works better in less humid environments (more humidity in the air reduces evaporation of the mist from your condenser coils which reduces the heat transfer). The Cool-N-Save works on very similar principles that an evaporative cooler uses. I'll warn you though, the Tulane study is a Mechanical Engineering study (it reminds me of the good 'ol days of lab reports) and is a little hard to read for the non-engineer. What I'd really like to see is a comparison of the electrical power consumption a unit operating with the Cool-N-Save and without it (you'd have to make sure all external variables - temperature, humidity, thermostat setpoints, inside starting temperature, etc. - are the same).
Since I just found out about the product and air conditioning season in Atlanta is slowly winding down, I plan on purchasing a unit next spring and testing it out for next summer. In any case, I definitely believe this product is worth investigating some more if you want to save money on your summer cooling bills.
To do a very unscientific analysis: I estimate that I spend about $300-400 per year on cooling my home. The Cool-N-Save unit costs $99. I have 2 AC units, so if I wanted to get Cool-N-Save's for both units I would spend $200. If it saves me 20% on cooling costs, in two seasons then I've almost paid for the units. Chances are many families spend much more than I do on cooling.
The biggest issue with the Cool-N-Save seems to be water sediment clogging up the misters. This forum has one person who didn't like the Cool-N-Save and one who did, but I think it demonstrates some of the issues people may have. They offer a water treatment system with 3-month ($29.95) and 6-month filters ($49.95) they recommend if you have hard water (high mineral content in your water). If you have a shorter summer you'd go with the 3-month filter. Keep in mind that this would be an annual purchase.
My original plan for the OpenSky store was that I would only promote items I've tested. While I haven't tested the Cool-N-Save, I believe the Tulane study and the fact that I've seen the same thing at work at at Southface gives us reason enough to add it to the store .
The below video shows how the Cool-N-Save sets up on your AC unit with your favorite Green TV show host, Ed Begley. He was also featured in a video we showed on our post on the GreenSwitch.