Beer Can Solar Heater

Why should you consider building/using a beer can passive solar heater?

• Accelerate the heating of a cold room without relying on your home furnace
  
• Reusing (instead of recycling) perfectly good cardboard and beer cans (soda cans are OK too) instead of trashing them
  
• Keeps you from having to stand in line to get your deposit back on your cans
  
• Wacky conversation piece with your friends and neighbors
  
• Instead of buying a sheet of aluminum for $24 at home depot, you get to drink $24 worth of beer
  
• You don't have to perfectly shape a sheet of aluminum. Instead you poke holes in beer cans and stack them.
  
• Gives you another good use for duct tape
  
• Family fun in constructing beer can towers
  
• Educate your kiddies to the various kinds of beer by using the project as a sorting drill. (eg: MGD goes in this stack, Hamm's goes in that pile.)
  
• Makes your neighbors thankful you didn't build an external unit onto the outside of your house.
  
• Makes women jealous that their man didn't think of doing it. Actually, they're jealous that their men didn't DO anything - and that you did!
  
• Your wife loves that you actually got off your butt and did something constructive.
  

A passive solar heater is simply any device that spreads heat from the sun's rays. So you could easily just hang a black metal panel in the window and it (technically) would be a passive solar heater - but not a very optimized good one.

Also, passive solar heater doesn't use a motor or fan to force air or water through or around the device. That's active solar heat - not passive.

Some passive solar heaters are intended to heat air only, others are intended to heat water. And unless I'm mistaken, a passive solar water heater, in theory, could radiate enough heat to heat the air.

However, for our purposes, and because we're dealing with beer cans - we're going to focus on heating the air that enters our beer can passive solar heater.

First we emptied 56 cans of beverage. Then we rinsed and let air dry the cleaned cans.

My wife, son, and I formed a processing line where my son fetched the clean, empty cans, I used a mini-wonderbar and hammer to tap an 'x' into the bottom of the can, and my wife used a socket extension to widen the 'x' in the can bottom and also pry-back the flap at the can's to opening.

(No, those aren't her hands in the photos below...)

We should've used gloves when handling the aluminum cans.
No incidents occurred. But they could have.

Tap the wonderbar firmly with the hammer.

Remove, rotate 90 degrees, and tap again.

This completes making the cross.


Socket extension fat end.

Above: tapped into can and rotated to push the flanged aluminum
from the 'x' up into the can (away from fingers).

Socket extension skinny end.

Inserted into top of can mouth to push back the flap that was originally
pushed in by the tab when the can was opened.

For our purposes, we used aluminum adhesive to adhere the cans in stacks.

After the aluminum adhesive was drying I gently placed the cans in the cardboard
frame. Then I painted the cans with flat-black stovepaint.

Some of you may wonder which column of cans heats better than the others?
Schlitz? Icehouse?

Keep guessing...

After the paint dried on the cans, I cut a couple sheets of styrofoam
and placed strips of duct tape across to help keep the cans from slipping
during the cellophane wrapping stage.

Here's the styrofoam with duct tape.

A photo from one perspective of the cans.

A a photo from another perspective.

With cellophane wrapped around the cans.

Cellophane wrap was used in order to 'lightly' bind the can silos together
to the duct-taped styrofoam. Now they can be placed into the carbard frame.

A closeup of the bottom of the stacks.

The cans are sitting on a 1x1x? small piece of styrofoam to ensure the cans
aren't sitting on the cardboard (for better cold-air-intake).

Bottom of can stacks, from outside.

See how the vent in the bottom of the box allows cold airflow directly into
the bottom of the can stacks (most of them).

Raising the cans by the 1x1x? styrofoam allows air to reach the outermost stacks
since the vent (for cardboard strength purposes) isn't as wide as the box or stacks.

Hard to see but the slot is there.

Look carefully for the slot on the back of the top of the box.

Instead of a cutting a hold in the top of the box, I cut one in the back
of the box. Again, I did this because I thought it would leave the box structure
stronger than if the vent was in the top.

I could've glued the stryofoam to the cardboard. But because I thought I might need to tinker more, I attached small lightweight magents to the back of the styrofoam, and also the to the inside of the cardboard box (opposite poles attract, remember).

Then, with two bungees looped at the top of the box, I hung the box in the window.

We have windows facing southeast, and some facing southwest.

Bungees at top to attach to "HEAVY DUTY" blinds.

Don't try this with any lightweight curtain rod. Your wife will be ticked,
and you'll have to fix your mistake anyway.

It's easy to see the thermometer beneath the window.

Beneath the window it measures the temperature of cold-air going into the device.

Not-so-easy-to-see (if at all) is the thermometer inside the top of the box,
which is what measures the output temperature.

Does it work for me? Absolutely.

Actual results are below...

Temperatures reached with sun shining through old
and inefficient (Non-Low-Z) window glass.

The entire unit weighs a paltry 4 lbs. 3 ounces.

Here's how it breaks down:

We had a blast building the unit, and building this page. We know you probably had a chuckle, and shook your head too.

I now have plans to build a similar device with a clother dryer exhast hose and see how it compares to the beer can solar heater. Make sure you add us to your favorites so you can check back easily when we put the link to the new lens.

Also, I'll continue to provide the actual temperature readings from this device in future days, in the space above. With specifics about time of day, window direction (Southeast/Southwest), input and output temperatures.

Check back later for more!

I hope you've enjoyed!

Please give us 5 stars! And then tell your friends about us!

It's funny how many people enjoy seeing something this oddball.