Solar Water Heating

You can generate hot water for use in showers, baths in your home with solar water heaters. In any climate you can have solar water heating systems and the fuel that they use is free sun light. Solar water heating (solar thermal) panels shouldn’t be confused with solar electric panels which produce electricity from sunlight.

Solar water heating systems are categorized in two different types; first one is the active one which has circulating pumps and controls another one is passive one which doesn’t. Some form of external power is required for operation in active systems. Active ones are also two types; direct circulation systems and indirect circulation systems.

Direct circulation systems work well in climates where it rarely freezes and in this system pumps circulate household water through the collectors and in to the house. Indirect one heats the water then flows into the house and mostly they are popular in climates prone to freezing temperatures. In this system plumps circulate a non freezing fluid through the collectors and the heat exchanger. When we compare the prices of passive and active solar water heating systems passive ones are less expensive than active ones but they are not as efficient as active ones.

Solar Collectors

Solar Collectors

Solar collectors are categorized in three different types; first one is flat plate collector, second one is integral collector storage systems and the third one is evacuated cube solar collectors. Evacuated cube solar collectors have evacuated tubes each with a liquid filled copper conductor inside. In flat plate collectors before water returning to the cylinder it passes through the whole plate where it is heated.

Evacuated tube collectors are generally more expensive and efficient. In the world the most widely used kind of collector for domestic solar water heating is flat plate collector. These durable and effective collectors are the standard to which all other kinds of collectors are compared. An integral collector storage unit has the solar hot water storage tank as the solar absorber. The tank is painted black or coated with a selective surface and it is mounted in an insulated box with glazing on one side.

The sun is warming the water inside the tank. These types of collectors are mostly used around the world in climates that never experience freezing conditions and they work great. Your roof has to be strong enough to hold tank’s weight because these collectors are very heavy. There are also pool collectors and concentrating collectors.

The best place to store collectors is inside a building. If they are well covered collectors can be stored outside. Collectors can get very hot if they have direct sun and can cause burns when you touch with bare hands especially if they are evacuated tube collectors. They never should be covered with plastic because they will get too hot. You can mount your collector array either on a roof or on a rack on the ground.

Collector tilt is very important because solar collectors will perform at optimum efficiency and maximum output if directly facing the sun. You should choose a permanent mounting angle that will be best for year round performance. For a solar water heater that will be used only during the summer or that will be used year round, a tilt angle will be different. You also should look for shading from trees, chimneys or other buildings.

The best way is having the top of the array as far up the roof as possible. The amount of snow will also reduced behind the collectors with this way. There are brass unions and copper couplers for attaching collectors together. Copper couplers are harder to use than brass unions. Solar water heaters have a life span of 40 years and over.

When the system has been sized correctly it can provide %50-75 of all your hot water requirements throughout the year.

Passive Solar Systems

Passive Solar Systems

Passive systems have two basic types such as integral collector storage passive systems and thermosyphon systems. First type system works very well in areas where temperatures rarely fall below freezing and in households with significant daytime and evening hot water needs.

Thermosyphon systems reliable but have a heavy storage tank. When warm water rises as cooler water sinks water flows through the system. Conventional storage water heaters usually provide backup as a part of the solar system package for cloudy days and times of increased demand. Back up heating usually provided by electricity or gas.

Passive heating systems are simple and need no electricity to operate so most of the systems installed worldwide are passive.