It is unlikely that anyone will argue with the fact that it is much more pleasant to live in a well-ventilated house than in a building where the air stagnates. In addition, regular airing has a positive effect on the he alth of the owners. However, along with this, a problem may arise: often the heat simply leaves the room through ventilation. To fix this, you can always use a device such as an air recuperator. This equipment will provide reliable heating throughout the house and will allow you to forget about the problem of heat loss. You can always buy such a mechanism in any specialized store, but to save money it would be much better to make a recuperator with your own hands. It is on this process, as well as on the features of this kind of equipment, that it is worth dwelling in more detail.
General concept of air recovery
Recuperation itself is a mechanism for returning some of the heat energy. And if we talk directly about the air, then this means heating the cold stream entering the room with the help of a warm exhaust exhaust. Similar designs are very common today. Their full name is the air handling unit, orsupply heat exchanger.
Here it is important to note one point: there is no mixing of incoming and outgoing air. At the same time, full recovery cannot be performed even with the most modern device (the warm-up rate varies from 60 to 80%). As a rule, the optimal parameter for warming up the air coming from outside is a temperature of 100 °C.
The principle of operation of the heat exchanger
As mentioned above, this equipment functions due to the exchange of heat flows. In simpler terms, during the cold season, the high temperature inside the room directly affects the air coming from the outside, while in summer this process is reversed. To implement such procedures, a special device called a recuperator was created.
The principle of its operation is as follows:
- air from a room moves along a square pipe;
- supply flows move in the direction transverse to it;
- mixing of hot and cold air does not occur, since there are specially designed partitions in the form of plates between them.
Types of air recuperators
In order to properly make a recuperator for your home with your own hands, you must first of all study the types of these devices. The most common of these are the following mechanisms:
- Plate heat exchanger. Based on the name, you can guess that its design consists ofspecial plates, which are combined into a single cube. The air currents that meet exchange temperature without mixing. This device has compact parameters and is widely used due to its simplicity.
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Rotor mechanism. This type of recuperator requires a source of electrical energy. Its cylinder is equipped with a rotary element that rotates non-stop among the air intake and exhaust channels. The dimensions of this device are very large, as a result of which it has received its distribution mainly in industrial enterprises. Nevertheless, the efficiency of its work is very high - about 87%.
- Equipment operating on the principle of water recirculation. According to its technical characteristics, it resembles a plate-type model, however, the device itself of this mechanism is much more complex, and the main difference is that some of its structural details can be located in different places. Either water or antifreeze acts here as a coolant, circulating exclusively forcibly with the help of electricity.
- Roof heat exchanger. This model is not suitable for residential premises and is used only for industrial purposes. The efficiency is from 55 to 68%, and the installation of such mechanisms does not require significant financial costs.
The most simple to operate and connect, as well as the least expensive is a plate heat exchanger,therefore, making it yourself will be the easiest.
Advantages and disadvantages of a plate heat exchanger
As mentioned earlier, this mechanism will be the best option for your own design. The advantages of this type of recuperator include the following:
- high efficiency (40-65%);
- the absence of any difficulties in the design of the device (the device does not have any moving elements, which significantly prolongs its service life);
- no extra cash costs, since electricity is not needed for its operation.
However, it is almost impossible to find mechanical equipment that has absolutely no negative sides. So, from the shortcomings of a plastic heat exchanger, it is customary to single out the following:
- the device is not equipped with a water exchange function, but there is only the possibility of heat transfer;
- equipment is prone to ice formation during the cold season. But this problem is solvable: in order to prevent freezing, the device can either be turned off or equipped with a special valve called a bypass valve;
- the design of such a heat exchanger has pipes crossed among themselves;
- avoiding the installation of these items will not work, and the process itself is quite difficult.
Equipment for hand-made plastic heat exchanger manufacturing
To make a plastic heat exchanger for your home yourself, you need the followingmaterials:
- 4 m² of roofing iron treated with zinc, or the same amount of sheet aluminum, textolite, copper, getinaks;
- technical plug having a thickness of 0.2 cm, which acts as a gasket between the heat exchanger plates. For these purposes, you can also use a wooden lath soaked in drying oil;
- regular silicone sealant;
- tin, metal or plywood box designed for the body of the device;
- 4 plastic flanges to match the air pipes;
- sensor displaying differential pressure;
- corner for racks;
- insulating material (mineral wool);
- electric jigsaw;
- hardware.
With all this equipment, you can start making a heat exchanger with your own hands.
The process of creating a heat exchanger
The algorithm of actions is as follows:
- The material needs to be laid out and cut into square-shaped plates so that the size of the faces is 20-30 cm. In total, about 70 units of such cassette blanks will need to be made. It is necessary to cut the material with an electric jigsaw so that the plates are perfectly even.
- Then you should prepare cork or wooden slats so that their parameters correspond to the sides of the square. They need to be glued to opposite sides of each of the blanks, with the exception of the last one. After that, it is important to wait for the glue to dry completely.
- Next, you need to start the process of assembling squares into a cassette. The heat exchanger scheme involves laying each of the sheets in relation to the previous one at an angle of 90 °. The last part of the construction will be a plate on which nothing has been glued.
- After that, the future heat exchanger needs to be pulled together with a frame. Here you will need to use the corner.
- It is important to seal all cracks with non-corrosive silicone sealant.
- Next, fasteners should be made to fix the flanges on the cassette walls. The lower part of the part must be equipped with a special drainage hole, where the condensate drain pipe must enter.
- Guides made of corners are fixed on the case walls. For carrying out any maintenance work, the cassette can always be obtained.
- The part is mounted inside the case, the parameters of which completely coincide with the diagonal of the square.
- When making a heat exchanger with your own hands, it is important to remember about laying the insulating material, which in this case is mineral wool. It is necessary to take a layer of this insulation with a thickness of 40 mm and fix it from the inside on the body walls.
- To save yourself from the problem of ice formation, the structure should be equipped with a pressure sensor, which should be installed at the place where warm air passes.
- The assembly process is completed by installing the finished heat exchanger in the ventilation system.
As a rule, the efficiency of such self-mademechanisms is approximately 65%, which is quite enough to maintain a favorable microclimate in the living room.
How to calculate the heat exchanger capacity?
When assembling such a device as a recuperator with your own hands, it is very important not only to correctly carry out all the measures for its manufacture, but also to correctly calculate the power of this mechanism.
To determine the optimal indicator of the heat energy that circulates between the plates, it is customary to take the following formula as a basis: 20 WxSdT. S in this case represents the area of the plate measured in m².
Calculate the power of the equipment using the following formula:
p (W)=0.36Q (m³/s)dT.
All variables are decoded like this:
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Q - the energy spent on heating or cooling the air flow. This parameter is calculated using the formula 0, 335 x L x (t end - t start), where:
- L is the air flow measured in m³/h. In accordance with the norms of the installation, this figure per person should be 60 m³ / h;
- t start - initial temperature indicator;
- t con - parameter obtained as a result of heat transfer.
- dT – temperature.
Ways to improve ventilation
In order for the equipment to work comfortably, there are some options for improving its functioning. These measures will certainly increase the consumption of electricity, but the efficiency will increase.
To clean the air entering the recuperator fromdust particles, its channels can be equipped with special filters consisting of aluminium, plastic or fiber. But these elements must be monitored and, if necessary, replaced.
It is possible to avoid freezing of the structure by periodically turning off the supply fan. This will cause the plates inside the movement to be warmed by the outgoing warm air and, as a result, to thaw.
Compliance with all the above recommendations will allow you to create a high-quality and reliable model of the heat exchanger, and the manufacturing process itself will not take much time and effort.
