What you need to do to build your solar powered heater.
A simple solar panel is backed with black pond liner, which is water proof and also an excellent solar absorber. The panel is sealed with plexi-glass and so it is water tight. You will then need a tube to connect the bottom of the bucket to the bottom of the panel, and another tube connects the top of the panel to the top of the bucket.
As the sun shines down , the panel heats up thus heating up the water which then rises up the path until it reaches the top and passes over into the bucket.
The solar panel is made as pictured toward the top of this article. It is backed with black pond liner which is both waterproof and an excellent solar absorber. The panel is sealed with plexiglass and so it is water tight. A tube connects the bottom of the bucket to the bottom of the panel, and another tube connects the top of the panel to the top of the bucket.
When the warm water leaves the panel, more water gets sucked back into the bottom of the panel. This is colder water from the bucket, therefore the cycle continues; hot water being passed from the panel into the bucket, and cooler water being passed from the bucket into the panel to be heated further. It is a good idea to keep the bucket well insulated and kept shelltered from the wind so that heat is not wasted.
Make sure that you find a good location for your heater, for maximum solar exposure. Find a sunny south facionbg location , and try and keep iot close to the back up heater to minimize the piping distance. Placement and orientation are the single most important considerations. Remember that the sun is high in summer and low in winter.
Once you have found your sunny location, you need to determine where your heater will be installed-roof, platform, wall or ground- keeping in mind that a your tank is going to weigh a lot when filled with water. For most applications it is best to keep a large solar heater on the ground on a specially built platform. Ground mounting is easier as you can control the weight easily.
Now its time to choose what type of tank you are going to use, the most efficient are thin cylinders because they have the greatest ratio of surface are to water volume. You can get these cheaply by looking out for used electric water heater cores. Wire brush your tank, and paint it with rust-resistant flat black paint.
You can actually order glass lined electrical water heater cores brand new, that’s if you are picky about using a second hand one.
Make sure that your system will retain heat. There are a number of options for glazing the top and the south facinbg wall of your unit, including single and double paned glass or fibre glass and plastics designed for extended solar exposure. In most cases, you should use two layers of your chosen glazing ]material with an air space between to provide maximum heat retention.
Glass is generally a suitable glazing for owner-built heaters, unless you get severe hail. Twin-wall polycarbonate is a tough alternative. Be sure to flash the glazing carefully to avoid leaks and to glue and seal the panes to avoid condensation, which can limit energy capture.
Now you need to make sure that size of your heater is appropriate, to do this you will need to allow 30 gallons of hot water per person in your household, if you think this is too much you may be able to cope with 10 gallons per person.
You should plan for 1 to 2.5 gallons of water per square foot of glazing as a general ratio for good heating. A smaller water to glazing ratio speeds up the gain of heat by a considerable amount but can also increase the freezing risk. A smaller system will still provide economical solar water pre-warming and conserve nonrenewable energy and cash.
You are planning to use this through out winter, make an efficient freeze resistant connection to the back up system. Minimize the pipe runs and be sure to insulate the pipe carefully using foam or fibre glass with the aluminum jacketing.
It can take up to 72 hours at 12 degrees to freeze an exposed water heater tank; but pipes are much more vulnerable. In other words, you can leave the hot water on slightly to keep the pipes from freezing. In very cold winter temperatures, drain the collector tank and pipes in the fall.
Set the system up so that you can turn off the backup heater and run solar hot water straight to the users, and so that you can shut it down in winter when you want to drain it.
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Posted under Articles, Climate, Gardening & Outdoors, Gas & Electricity, House & Home, How To's & Guides, Money & Finance, Renewable Energy
This post was written by Xavier Tikadar on July 30, 2008