Homemade, Off-Grid Air Conditioner

Make a homemade air conditioner using a small fan, a plastic tote, and some frozen jugs of water.

June/July 2017

By Robert D. Copeland
Photos by Russell Mullin

off-grid air conditioner
The "Chillbilly" air cooler is backwoods, off-grid, and dirt-cheap. Photo by Russell Mullin.

I’ve been accused of being a lot of things: a cheapskate, a hermit, a used-car salesman, and one lady thought I was the ghost of country singer Keith Whitley. But I’ve never been accused of being someone who would buy something new and expensive when I could either make one myself, splice a few old gadgets together, or do without. DIY is my thing, y’all.

It gets hot here in Texas. And nobody wants to sit around all day in the 100-degree-Fahrenheit heat for four months out of the year. If you live off-grid like I do, work in your shop or barn all day, or worry that your animals are getting too hot outside, cooling your space can be a challenge. I run my cabin and farm on batteries, solar panels, and a homemade wind generator (which you can learn how to build), so cranking up traditional air conditioning is really too much of a drain on my small 12-volt electrical system. I’m trying to use less juice, not more. But when July rolls around here in the northern territories of Texas, I’m looking to cool off just like the next guy.

Fortunately, I do have a freezer, and in that freezer, you’ll find at least a dozen 1-gallon jugs of ice. One night, when it was still 100 degrees at 8 p.m., I thought I’d put a few in with the chickens to see whether it would cool them off a bit. When I peeked in the coop later that night, they were all sitting within a few inches of the milk jugs. Chickens are smart.

I figured if I could cool off the chicken coop, then I could cool off my tiny home made of straw bales and earth plaster. It’s only 15 feet by 24 feet, with a 15-foot-high peak, and the suction fan upstairs draws the accumulated heat out while a box fan in an opposite ground-floor window brings fresh air in. That fresh air can get up to 95 degrees in the shade, though, so I came up with a cheap, efficient, and low-voltage way to cool my cabin.

How to Make an Off-Grid Air Conditioner

I call it the “Chillbilly” for the simple fact that it’s backwoods, off-grid, and dirt-cheap. The Chillbilly cools off my house for approximately five hours with a single batch of ice jugs, bringing the inside temperature down into the 70s or low 80s during the hottest part of the day. Giving it a try will cost you all of 30 bucks. And even if it won’t cool off your big house or barn, it’ll cool off a cabin, a shed, or a coop long enough to survive the dog day afternoons.

Materials

• Plastic tote large enough to hold six 1-gallon jugs (18-gallon totes work well)
• 12-volt fan, preferably a small, high-velocity fan with louvers (a small 120-volt fan will also work)
• 4- to 6-inch round grate or, if your fan doesn’t have louvers, a small household floor vent with louvers
• Towel or pad for the tote to sit on to prevent condensation from getting on your floor, table, or stand
• Six 1-gallon jugs of frozen water

Tools

• Marker
• Sharp utility knife
• Duct tape (optional)

measure for fan

1) On one of the small ends of your tote, trace around the outer case of your fan. Then, on the opposite end of your tote, trace around your vent.

hole for fan placement

2) Carefully cut along the traced lines with the utility knife.

install fan and secure

3) Place the fan inside the fan hole, with the air flow directed either into the tote (if your fan doesn’t have louvers) or out of the tote (if your fan has louvers), and secure with duct tape if necessary. Now, place the vent in the hole at the other end so that it’s facing out from the tote. Secure the vent with duct tape if needed.

frozen water jugs

4) Place frozen jugs of water inside the tub, and replace the lid.

5) Plug the fan into a 12-volt electric source and turn it on. The air flows through the tub, cools off as it comes into contact with the jugs of ice, and is blown into your cabin or coop (depending on who you plan to spoil first).

6) When the ice has all melted, and the day is over (hopefully), replace the jugs in your freezer overnight for use again the next day, or keep extras to trade out with the spent ice jugs and keep ’er runnin’ all night.

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