That is a unique way to get rid of your old pop cans. I�m sure it would work quite well. But preparing all those cans, the washing, cutting, gluing together, has got to be rather tedious.
I experimented with something similar a couple years ago. I built a 4 by 8 foot box and with Styrofoam insulated the sides and back. But rather then using pop cans I added partitions to force the air to zigzag it way up from the bottom to the top.
Starting with ambient 50 degree air and with just convection moving the air through it I was getting 130-140 degrees at the outlet. Adding a small fan to force air through it there was a nice 95 degree breeze coming out.
I never did try hooking it up to the house as my south facing wall is shaded by fir trees.
The white thing stuck on the front is an obelisk that I used to get it aimed at the sun.
The nice thing about these air only systems is they are easy to construct and they actually work.
The ones that use water/antifreeze to transfer the heat have some advantages but if the plumbing develops a leak that can dampen the pleasure of having solar heat.