If you've been looking around for a new conditioner, you couldn't have failed to catch a couple of ads from LG for their latest, a solar air conditioner. They picture a pretty girl standing next to a large outdoor unit with a small solar panel on top.
The thing is, the best that that solar panel can do is put out perhaps 100 W. That air-conditioner needs at least 1500 W of power. What on earth is that solar panel going to do? Well, you could say that it's a gimmick. LG wants to get in on the "solar air conditioner" hoopla without actually making something that really helps. But there are other products that do more.
For instance, Lennox has a new product out called the SunSource. Each air-conditioner they sell comes with a huge solar panel. Lennox says that the SunSource system can run on half as much power as a conventional air-conditioner. But even that doesn't seem entirely believable. Their solar panel puts out about 200 W of power. While that's better than what LG has, it's still very little compared to what your air-conditioner needs. Apparently, their solar panel can take care of both fans in your air-conditioner the one on the indoor unit and one of the outdoor unit.
Basically, if you really want to run a full proper air-conditioner with solar power, that's going to be quite expensive. You are going to have to cover your entire roof in solar panels. There's really no reason to call it a solar air conditioner. It's just air-conditioner hooked up to a solar panel.
Some people like to describe a swamp cooler or evaporative cooler as a solar air-conditioner. Don't let that fool you though. An evaporative cooler does not cool the way an air-conditioner can, at all. It only works under certain conditions when the weather is dry and not very hot.
Gratefully, there are some real new solar air conditioner techns out there. Coolerado is a company that manufactures very powerful air conditioners that run on the 20th the power of conventional air-conditioner would need. For instance, Coolerado has a 12,000 BTU solar unit that just takes 50 W of power. That's so little, you couldn't run a fan on it. And yet, this is an air-conditioner that actually works.
These air conditioners certainly do have something in common with swamp coolers. They do use the evaporative cooling power of water. The difference is that these units don't send you the cooled air directly. They dehumidify it first. So what you get is cool air that's dry. Unless you happen to live in Texas or another very hot place, these systems do work.