The systems often applied in the global market are three types.
1- Parabola system: It is a solar heater that is distinguished by the fact that the tank is the same as the solar collector and is located within an external container and includes reflectors that reflect the solar radiation on the tank in the center of the external container (the outer structure)
This type is distinguished to withstand difficult operating conditions such as places where it is difficult to install normal systems, or the consumption of hot water is unstable relative to times such as chalets or country houses, where the user does not consume hot water for long periods and therefore a very high temperature and therefore high pressure.
One of its most important advantages is that it is easy to install and easy to maintain, there are no malfunctions
One of the most important specifications of a parabola is to withstand working pressure of up to 10
2- Flat Plate Systems
, Which is the most popular system as a result of people accustomed to it for more than 60 years
In fact, the system is very popular in Egypt because the customer got used to it and knew its features and somehow trusted the product.
One of its most famous specifications is that it is relatively easy to install, and the efficiency of the complexes does not exceed 80% at its best, due to the isolation method used. And its price is relatively high because of the type of raw materials manufactured from it, the assemblies are often made of copper and selective aluminum.
The tank is of two types:
Pressurize Tank and from it there are multiple types and brands, the best of which is the ceramic-coated tank or Enameled coating to withstand hard water and to contain a magnesium column in the case of hard water or demoralized salt for its extreme popularity of interaction with minerals and has several types, including double jacket or Tube heat exchanger
It is preferable that the connections be made of treated and insulated copper, and that the assemblies be a Selective coating and consist of two circuits. The first is a special circuit (closed) containing the thermcouple and the second is the cycle in the tank.
An open circuit with low pressure or normal flow cannot handle pressure
And it was in force in the local market for not long ago and is still in effect in many countries such as Greece, Turkey, Jordan, Syria and others.
The difference between the compressed and uncompressed systems
The first works on a network that operates by pressing the network or water lifting valve, and the second works by natural flow (air pressure) and does not bear any pressure in the feeding line and often has an auxiliary tank to avoid drying the system.
3- Vacuum Tube System
It is a less flexible system in handling "during installation only" relative to the flat panel system
It takes technicians knowledge to choose the right system for the right place
(Here is the core of the problem in the Egyptian market) and its types are as follows:
- Low pressure system: It is, as in the system of low pressure or open circuit in flat panels, but it is often provided with a control panel consisting of a level and temperature sensor and a valve for filling and compensation.
The technician should consider placing the sensor and the valve in the right place to avoid common mistakes
One of the most important recommendations in its composition is that the place be permanently in the presence of water, otherwise it will be exposed to dehydration and thus damage to the pipes. (Attached to the picture)
Coil Pressurize System
, Of which the first two types are SWH with coil, which is very similar to the low pressure system, but add a heat exchanger or Coil, as the tank contains the liquid responsible for maintaining the thermal output, and the hot water is delivered to the consumer through an internal heat exchanger or Coil that exchanges heat between The water inside the exchanger (consumption water) and the thermal liquid inside the device
Often the internal fluid is normal water or rare cases Glycol, or depending on the nature of the place
It is considered one of the best solar heaters for home use at all (in my view), because the high temperature in the solar system does not affect plumbing networks and does not constitute a rise in pressure. And its control panel is useful for automatic maintenance and protection of the system from drought. And it is almost a system without defects if the correct installation conditions are observed.
Heat Pipe Pressurize System
It is very similar to the compact system in flat panel systems, but it consists of one circuit (consumption circuit only)
The heat transfer medium shall be a liquid embedded with a copper tube inside the vacuum tubes, which shall be connected to the tank in special pockets called the Heat Pipe.
In general, opinions differ between the above mentioned types, but the scientific opinion is "the most important".
The vacuum tubes system is generally better than flat panels
Because of the relatively low cost of production with flat panels and higher efficiency
It searches for the efficiency of vacuum tubes to absorb up to 94%.
I will accompany the pictures as much as possible to explain