Home & Garden

Obviously, a solar water heater creates hot water by absorbing energy from the sun. But what happens in the winter when there is less sun, or on overcast days?
Well, to some extent, the heater will still work, but the chances are that you will accumulate less heat, which means that you will probably need an alternative form of heating.

Many hot water cylinders have two independent heat exchangers. One is connected to the solar heater and the other connected to a conventional boiler. Additionally, many cylinders have an aperture for an electric immersion heater.

How you use the hot water that you create from your solar heater is entirely your choice. One idea I had was to create two heating panels supplying different parts of the house (bathroom and kitchen). In the bathroom, we would obviously prefer to have a constant supply of hot water, which means that we would probably need a dual heat exchanger cylinder. For the kitchen, however, it is less critical because we don’t use nearly as much hot water in the kitchen as we do for showers and baths.

The washing machine is not fussy. If it is supplied with hot water, it uses it. If it is supplied with cold water, it heats it up to the required temperature. So if the hot water tank is emptied of hot water, the washing machine will still operate, albeit less efficiently. Today’s modern detergents work in lower temperatures anyway, so they are already saving us energy.

My reasoning behind having two solar heaters is that I have two prime locations for the collectors and they happen to be convenient for the both the bathroom and the kitchen. It also means that if we run the washing machine, it will not affect our ability to have a bath or shower.

If you think this is all a little ad hoc, it doesn’t really matter. The investment in home-made water heaters is little enough that they will pay for themselves in a very short time period.