They are units made up of a flat solar collector and an accumulator tank, which make it possible to take advantage of all the available solar energy to increase the temperature of the drinking water.
Solar collectors (solar water heaters) are used to heat water, which can be used for showering, washing dishes, in underfloor heating systems or radiators, and for industrial processes. With these equipments temperatures of 50 ° C in winter and 80 ° C in summer are obtained.
Having a solar hot water tank reduces the annual consumption of energy required (gas or electricity) by up to 70% for the production of sanitary hot water. They do not require a pump or electrical connection for their operation. They also have a long service life and low maintenance.
How do they work?
The solar water heater produces the heating of cold water through a principle called "thermosyphonic or thermosyphonic effect" that takes place in the vacuum tube collectors.
The cold water housed in the vacuum tubes will heat up because they have the property of absorbing solar radiation. As the water housed in the vacuum tubes heats up, its density decreases noticeably and therefore it is directed through the tubes towards the accumulator tank generating a counter circulation of cold water from the tank towards the tubes, to repeat the heating cycle once and again until all the water has been heated.
The vacuum tubes absorb not only direct solar rays but also diffuse solar radiation, allowing the water to be heated even on cloudy days with sun.
When water is not consumed for a long period of time, the water does not overheat since the solar water heater has a vent that ensures that the water does not increase its pressure or reach a maximum temperature. Also in extremely long periods without water consumption, it is recommended to place a cover over the collector.
The installation of the solar water heater is always better to do it in the direction that provides a greater amount of solar radiation. The best orientation of the solar hot water tanks is towards the north, and in the central zone of Argentina, an inclination of 40 or 45 degrees.
The tanks of the solar water heaters have a capacity of 200 liters, with a coverage of 50 liters per person (that is, 4 people).
Although the temperature that the solar rays provide is generally much higher, it is controlled for the supply, mixing with cold water. The pressure that the solar water heater tolerates is between 0.3 and 1.0 bar depending on the case.
With information from: http://solarproargentina.com http://www.sustentator.com