Sunday, September 11, 2011

Discount Air Conditioning

I have a Cruise-&amp-Carry AC unit. We have a love-hate relationship. It's heavy, blocks some of the view, and is in the way when stowed below. It snags genoa sheets. I can only use it when plugged in at the dock because of the power demand--I could run a 2000 watt genset, but that's just too much total noise and too much complication.

Lucky folks are enjoying trade wind AC about now. I don't want to hear about it. Actually, the Chesapeake is beautiful this season, but I'm writing about summer. Still air, temperatures in the mid-90s to 100s, and all the humidity you can stand.

A few years ago I was in Annapolis with my parents for an over-night.We'd finished the tourist thing, were fixing dinner, and were listening to thunderstorms grumble in the distance. We were going to watch an old movie around the salon table after dinner. However, even with the slider open, when we close the rest of the hatches it gets darn steamy fast, and the heat of cooking doesn't help. We needed to do something.

When we bough the boat it came with a 20-inch fan, hidden away in the huge under-bunk lockers. I figured it was for drying things out or something, but was clearly too big for convenient use. But desperate times call for desperate measures; I decided to set it somewhere, just to get some air moving. It fit nicely on the chart table, swiveled to point up and over into the salon, and even on low it served as a silent ceiling fan. You can still slide by into the head.

Since then we've found many uses:
  • Ceiling fan. Sit it on the cart table and aim it up. Even on low it moves a lot of area around the cabin, 10 times what the 6-inch fans can manage on low. It is also whisper quiet in that location, perfect for watching a movie.
  • Sleeping cabin fan. Place it in the door and try medium if it's really hot, low if not. It's not too high to step over.
  • Salon door. Same idea.
  • In the cockpit, if stuck in a marina and it's sizzling hot.
It draws 0.6/0.8/1.1 amps @ 110v AC (confirmed by ammeter) (about 6-12 amps at 12 volts from the batteries, post inverter) depending on the speed setting, about 66-121 watts, or about 10x less than AC. About 70 amp-hours if you run it all night on low--though generally at some point in the night we turn it off--a manageable load easily handled with a solar panel system. There are many equivalent models, probably even better models; be certain to get one that is very quiet on low and that swivels up. It moves 1400-2000 CFM: compare this to the 225 CFM and 0.3 amps of a typical cabin fan. Oddly, not as energy efficient, but much quieter than 10  6-inch fans!

One of our best finds.


  1. Great info! Our little window unit won't do much good when anchored out. We definitely need one (or more) of these!

  2. Heating season has arrived here, just a bit early. Or low Friday was 45F; the first heater use of the season.