Making a Homemade Air Conditioner

Here's a cheap and simple way to build anexcellent conductor of heat.
air-conditioning unit using simple household items. ToLastly, place the fan in front of the opening, and put
build the unit, the items and materials you will needa sheet or whatever you have (which serves as a
are:lid) on top of the duct, leaving a small opening for the
· Fanair to blow out of, after making its way around the
· Wood (pieces of 2x4)duct. You may also want to seal part of the opening
· Metal container (such as a garbage can,above the fan with an old newspaper so that there's
approximately 15 inch tall by 13 inch diameter)no unnecessary gap above the fan where air can
· Circular sawescape before being cooled. This is a crude design
· Nails and a hammerfor sure, but it allows for easy fine-tuning, before
· Aluminum metal repair roll, thin sheet (18 inch xmaking something more permanent.
5 ft, available as a standard size at a hardware store)Now, turn the fan on and the air coming out should
At this point you may want to go to my website Itbe cooler. For my own unit I measured the exiting air
will give you a better understanding of what's goingas 2-3 degrees cooler than the air going in (I used a
on, as there are pictures there for you to look at.digital kitchen thermometer to measure). The ice in
The fan I used is roughly 8 inches in diameter. Thisthe container should last a few hours, and when
diameter will roughly dictate the size of the openingyou're done you can dump the water down the drain.
for the duct (but fan size is not critical). This openingThe advantage of this design is that you are utilizing
will be made out of pieces of 2x4.the entire surface area of the metal container to cool
Using the circular saw (making sure to wear eye andthe air.
ear protection and following safe operatingThe dimensions and sizes I used work together
procedure) cut pieces of 2x4 and nail them togethernicely. But of course, many variations are possible.
to make an 18 inch x 8 inch frame. The aluminum rollSome tips:
will attach to this frame, to form a spiral duct.· You can put salt (NaCl) into the container along
To form the spiral duct align the outermost end ofwith the ice. Due to the endothermic reaction
the aluminum roll with one of the 18 inch sides of thebetween salt and water, you will get a further
18x8 inch frame, such that the inside surface of thelowering of temperature. It may be a useful
roll touches the side of the frame. Adjust theexperiment, to see how much salt to add to get a
alignment so that the edges of the roll and frame aretarget drop in temperature.
flush, and then nail them together. Now, align the· Setting fan speed on low rather than high may
other end of the roll to the other side of the frame,result in cooler air coming out since the air stays in
such that the outside surface of the roll touches thecontact with the cold container longer.
side of the frame. Once again, make sure the edges· Well-placed fins inside the duct may help to
are flush and nail them together. You should nowimprove the flow and mixing time, thus improving the
have a spiral shaped duct.amount of cooling. This would be a good project for
Next, put the metal container inside the spiral duct,future work.
adjusting its position and that of the opening so that· In winter you can make blocks of ice outside,
the air blows roughly tangentially past the containerand store them in your freezer for when you need
on its way in, and with ample room to exit. Now, fillthem in the summer. I figure that to hold you over
the container with cold water and put a lot of ice inon those really hot days you need around 30 ice
it. The temperature of the water should drop to ablocks, each 4x8 inches, and one block for each
few degrees above freezing. The outside of thesitting. Remember, this is free ice and you won't be
container will quickly become cool, since metal is anloading your freezer.