Overall, the experiment worked and raised the temperature a few degrees, but some pressure issues were not fixed. Also, I don't know if only one radiator would have been enough.

Materials

A wooden box.

Black Polyethylene pipe.

Black painting.

Glass.

Nails.

Silicone

Fabrication

1.- Paint the wooden box with black painting.

2.- Makes 2 holes in one side of the box for inlet and outlet.

3.- Roll the pipe inside the box, using nails you can maintain the position of the pipe so it doesn't jump back to your face as a spring haha.

4.- Fix the inlet and outlet with silicone.

5.- Put the glass over.

6.- Go and test it.