Solar Hot Water - Enclosing Your Collector

Now that we have a basic idea of how solar hot water heaters work; let's take a look at building one. For our purposes we are going to build a passive system as these are the most cost effective and efficient ones. The simplest form of these would be to place a 55 gallon water barrel either on the roof, or a stand and pipe it into our house giving us hot water by mid day. This is probably the oldest form of solar hot water known, but we are going to improve on it to make it more effective and give us hot water for later when the sun has gone down.

For our system we will need to gather a few things together; none of which needs to be expensive and some of which can be gathered from you local scrap yard. Here is a list of the basic materials you will need to gather up:

2 hot water heaters: Used are good, they don't need to work just hold water.

½ inch plywood: Enough to build a box to hold your hot water tanks lying on their sides. The box will need four sides and a bottom.

A piece of Plexiglas: It needs to be big enough to cover the open face of you box.

Reflective material to cover the bottom and sides of the inside of your box: I use heavy duty aluminum foil.

Enough pipe (PVC or copper) to plumb your tanks together and to go from them to your existing tank inside your house and your cold water supply line.

Enough hardware to build your box and secure it to your roof such as small and large wood screws, hinges and a latch of some kind.

Now that you have gathered your materials we can get started. First we will build a box that is big enough to house your 2 hot water tanks laying flat on their sides. Make it roomy enough that there is some space between them, and around the sides of them for the sun to do its job. Line the inside of your box with the aluminum foil, I use spray-on glue for this. To make the box absorb as much of the sun's heat as possible; paint the outside of your box with flat black paint, black absorbs the most heat, think of the last black car your were in, when the sun was out.

When you have your box finished, it is time to mount it to the roof. It should be placed on the south facing side of your roof if possible, or if not; the side which gets the most exposure to the sun. Also it should be positioned so that the tanks are vertical, just as they would be if they were still on the floor. Make sure that you secure it well enough that it will not move under the weight of not only the tanks and box, but also all of that lovely free hot water.

We have our box built and installed on the roof, ready for the tanks. In the next article I will cover the installation of the tanks and plumbing them into our existing hot water tank. We will finish the box and have free hot water whenever the sun shines and well into the night.

Sources: www.motherearthnews.com, http://apps1.eere.energy.gov/consumer/your_home/water_heating