Filed under: Comfort at Camp, Preparation & Readiness, Summer 2011
THE POOR MAN’S AIR CONDITIONER – It is easy to make this one!
It has been a hot day. The temperature has hovered near 100 since mid morning. An early afternoon thunderstorm has added to the already stifling humidity. Clouds have moved out of the sky and there is no breeze. Welcome to a typical summer day in Central Virginia.
Our camper is sitting on a site in one of Virginia’s State parks – Lake Anna. We have no hookups and generators are not allowed after 8:00 p.m… The Ranger made his rounds about an hour ago and reminded us to silence the machines. The night air retains the heat and humidity of the day.
When we decide to go to sleep for the night I lay on the bed as the sweat pours out of my body, soaking the sheet below. I cannot sleep. It is too darn hot and the fan next to me doesn’t move enough air to evaporate the moisture on my skin.
Does this sound familiar? It doesn’t have to be this way – you can be cool and comfortable with a simple to make “Poor Man’s Air Conditioner” sitting at the foot of your bed.
The Poor Man’s Air Conditioner is nothing new. The concept has been around for decades – use a fan to blow air across a mass of ice. Just how cool the air becomes is dependent upon the airflow from the fan and the surface area of the ice. Of course, how long the cooling lasts will also depend on how much ice there is and how long it takes to melt.
This is how I built our Poor Man’s Air Conditioner. My design was dictated by the cooler, fans and tools I had to work with. The neat thing is that you can elect to use most any battery-powered fan and design the openings in the top panel to suit your materials.
A few more words before I get to the design: Block ice works the best. If you are planning ahead, you can freeze empty 1/2 gallon juice cartons in a freezer. The next best choice is ice cubes or large chunks of crushed ice. Last are the ice cubes with holes in the middle – these melt the fastest. If you need colder air, you can sprinkle ice cream salt over the ice. Just be advised this reduces the time you will have cold airflow.
Our 48-quart cooler packed full of ice cubes will give us at least four hours of cool air on a hot night – more than enough to get to sleep. The larger the cooler and the greater the volume of ice the longer it will last before it melts. We close the door in our fifth wheel RV’s bedroom to confine the cooler air. The Poor Man’s Air Conditioner will work well in a tent, Pup or any sleeping area where room allows the cooler to reside.
The battery for my fans is a $25.00 Wal-Mart 12-volt lawn and garden equipment battery (not pictured). It will power the fans several nights before it needs to be recharged. You can also find flashlight battery powered fans that work well in the camping section of most any Wal-Mart. I saw a 10″ model powered by D-cell batteries or an external 12 volt battery that would work great. I used the surplus computer fans because they were free. I like things that are free and always try to re-purpose them into something useful :).
A piece of 1/4″ thick plywood is cut to lay on the top rim of the cooler.
Here I have cut holes in the plywood for both the air intake fans and the cool air outlets. There are no set dimensions for the plywood top or the openings. You can make these round or rectangular – it is all up to you and the “parts” you may have on-hand.
I used four 12 volt “muffin” fans that came out of old desktop computers. They are 4″ square and use very little current. I used a hot glue gun to mount the fans to the underside of the plywood top and wired all of them in parallel to a single set of power wires about 3′ long with battery clips on the ends.
I packed our cooler full of chunks of ice. The round plastic vents were found at our local RV dealership in the parts department. You really do not need the vents, but having them allows me to direct the cool air as needed. They just lay in the openings. The red streamers are there so you can see that there is a significant flow of cool air out of the vents.
Purchasing enough bagged ice is kind of expensive since it takes two 20 pound or three 8 pound sacks to fill the cooler. That is about $9 to $12 from a convenience store. But, considering the low to no cost to make the contraption and the misery you can avoid it is, as the TV commercial touts, PRICELESS on a hot night.