Project 1: Build Your Own Flat Plate Collector

We are now going to make a flat plate collector. There are a number of different types of collector, all suitable for relatively simple manufacture in a home workshop. The key thing to remember about solar collectors is keeping the heat in and the cold out. This can be accomplished by using glazing on the sun-facing side of the panels and thermal insulation on the side that faces away from the sun. We need to try to
eliminate thermal bridges as far as we possibly can.

Aluminum clip fins are one of the easiest ways of assembling a solar collector quickly, as they essentially clip onto a matrix of copper pipe. Another way of constructing a solar collector is to use an old radiator painted black inside an insulated box—crude but effective! (Figure 2). This system contains more water, and as a result has a slower response time. This is because it takes more time to heat up the thermal mass of the radiator.

A home-made clip fin collector.Figure 2

            Warning.

One of the problems that solar collectors suffer from is freezing in the winter. When temperatures drop too low, the water in the pipes of the collectors expands—this runs the risk of severely damaging the collectors.