The solar collector is used to absorb the energy of solar radiation, so that later it is concentrated, converted and used by man.
- The principle of operation and scope ↓
- Advantages and disadvantages ↓
- Kinds ↓
- Flat collector ↓
- Tubular (evacuated) ↓
- How to do it yourself? ↓
- Necessary materials and tools ↓
- Tips ↓
The generated energy is used for:
- Ensuring water heating and starting heating systems for residential premises.
- Provisions in pools of various types with constantly warm water.
- Greenhouse heating.
- For heating process water used in industry.
The principle of operation and scope
The design and the materials used to create it are aimed at the maximum possible consumption of solar energy. After which it is converted into heat, and transferred for its further use. Coolant in this system, there may be both air and a special liquid with non-freezing properties.
Its circulation can be natural and compulsory.
Collectors are used in various countries with any climate.
Their scope is quite large:
- For summer houses, cottages and private houses.
- Various production complexes, regardless of occupation and scale.
- At car washes, gas stations.
- In children's and medical facilities.
- At the railway facilities.
- In hotel, shopping and entertainment complexes.
- In catering establishments and offices.
Advantages and disadvantages
Collectors have a large number of advantages, they include:
- Reducing the cost of maintaining the heating system at home, and providing it with hot water.
- The possibility of heating the house and hot water during interruptions and temporary lack of electricity and gas supply.
- Reducing the load on the heating systemas a result of which there is an increase in its service life.
- Saving natural resources and conservation of ecology.
- Environmental friendly system does not have a negative effect on humans.
The downside is the rather high cost and difficult installation of this equipment.
Two types of these devices can be distinguished. Each of them has certain characteristics and principles of action.
Such collectors are made in the form of a panel, up to 2.5 meters in size, in the center of which an absorbing plate is placed. It is made of heat-conducting metals, copper or aluminum are the most used for this. It is coated with a low emissivity.
This is required for the greatest conversion of sun rays in the form of thermal energy, while its release into the environment should be minimal. This absorbent layer is connected to the tubes. It is through them that propylene glycol most often circulates, which acts as a coolant.
Also, antifreeze can be used or water. A heat-insulating layer is located under the tubes. A special protective solar glass is located above the absorber. It is characterized by a minimum iron content for maximum throughput, and the case is reinforced with sheet steel with thermal insulation or aluminum.
This type is used for installation on pitched or flat roofs. But it can be mounted in any place and position. This type is the most common and has been widely used for heating systems and for heating water.
It consists of separate tubes. Their number can be from 5 to 30 pieces. Each of the tubes according to the principle of action is a mini-collector. All of them are combined in one panel.
Inside the tube is another smaller part of the same size. A vacuum has been created between them. The upper part consists of helioglass and performs the function of protection. An absorber plate consisting of copper or aluminum is built into it. A smaller tube is located under the plate; coolant circulates in it. Vacuum in this case plays the role of a heat insulator.
Such a solar collector acts much more efficiently compared to a flat one, in conditions of low atmospheric temperatures. But their cost is much higher.
The tubular manifold, in turn, is of two types, different in design. Distinguish type with a heat pipe and direct-flow. The advantage of the first type is the preservation of effective performance at temperatures up to -30 degrees Celsius, and in some cases even up to -40.
Distinctive features of the direct-flow collector is the possibility of its installation in any position, as well as minimal heat loss during operation.
How to do it yourself?
This device can be made with your own hands to save energy. There are many options for execution in this case. For example, it can be made from a window frame, an old electric boiler, a refrigerator, and even plastic bottles.
Consider one of the simplest collectors made with parts from an old refrigerator. To carry out such a collector will be heating water for technical needs.
Necessary materials and tools
- Capacitor taken from an old refrigerator.
- Bars of wood, 5/5 cm.
- Rubber mat.
- Glass (suitable from the window frame).
- Sheet of foil.
- Screws, nails.
Before carrying out work, the coil from the refrigerator must be washed with a detergent and running water. This is necessary to cleanse it from freon oil.
Next, you must follow the instructions:
- From the bars to knock the frame with nails, the dimensions are slightly larger than the capacitor.
- A rubber mat is attached as the back wall.
- On the bottom of the frame, from the inside, lay a layer of dense foil or foil thin sound and heat insulating material.
- Glue all the cracks where the foil and the body join, glue with tape.
- For maximum rigidity and reliability, nail reinforcing bars on the back of the collector.
- In the frame, make the holes necessary for the output of the coil tubes.
- The heat exchanger is mounted on the same holders that were removed with it from the refrigerator.
- Cover with glass of suitable size. Sealing with adhesive tape.
- Screw several screws from the inside into the frame, which will prevent the glass from sliding.
- The collector must be placed at an angle and for natural convection bend the top tube up. The storage tank must be above the collector level.
- If both tubes are lowered, then forced convection is required. It can be carried out using a small aquarium pump. With such a device, the location of the tank will not matter.
Tests have shown that this unit is able to heat about 20 liters of water at 20 degrees in two hours of operation. The ambient temperature during the experiment was +25 degrees Celsius.
Of course, such a device has low efficiency and the probability of failure due to airing of the heat exchanger, but nevertheless, it brings certain benefits.
Since, solar collectors have an efficiency that depends on reflectivity and absorbing features of the material, to increase these features were invented special coverings.
Each of them is suitable for a specific material on which they will be applied. There are coatings for copper, aluminum, etc. Their application is carried out in a rather complicated way, so they do not have wide access.
- When choosing a collector must be consideredthat its vacuum models are more fragile compared to flat ones, but with damage it is much easier to fix the first option. To do this, you just need to replace the failed tubes when, as if in a flat one, you have to replace the entire absorbent system;
- Powergenerated with a single collector is enough to heat several living rooms and heat water.
- The service life of the collector is up to 30 years. But when buying this unit, you need to consider that the vacuum type is less durable compared to others.
- You can install this equipment yourselfusing the instructions that came with the device. This process is quite time-consuming and difficult, but it allows you to save on the costs necessary to attract specialists.