Franco writes -

I completely changed the design of the earlier version. For this DIY Air Conditioner, I made a channel-shaped heat exchanger to optimize cooling.

Materials used:
• Aluminum repair roll ($10-15)
• Nuts, bolts, and washers ($5-10)
• Waterproof silicone ($5-10)

Total cost: $20-35

The heat exchanger is made from straight sections of aluminum (cut from the repair roll) bent into a U-shape, and bolted together, as shown (Figure 1, 2, 3). Silicone was used to seal the gaps along the edges and around the bolts.

Homemade air conditioner – Link.

Related:

Air conditioner make out of LEGOs – Link.

Homemade air conditioner – Link.

Poor Man’s Air Conditioning… – Link.

Homebrew Air Conditioning for under $25 – Link.

Homemade air conditioner – Link.