Plastic ventilation ducts for hoods: calculation and installation features

In the duct system, the ventilation pipes are the basic element. When they are made use thermal insulation, and the profile can be very different. As an optimal solution, the ventilation ducts are made of plastic for extraction, which have a rectangular or circular cross-section.

Carrying out of calculations

In order to ensure the normal operation of ventilation, it is first necessary to determine the purpose of each part of the system. Fittings, sectional shapes, pipes, as well as material for air ducts or hoods must be selected individually. Acquisition and installation work are always carried out after the drafting. The wizard should consider the installation, location and functioning of the system. This includes temperature regimes, room area, performance of elements, humidity and acoustic discomfort. Only in this way will it be possible to ensure the normal vital activity of man. When performing calculations it is necessary to take into account that rectangular and round pipes of insignificant diameter are capable of producing more impressive noises than wide-profile ones.

Determination of the section area

If you will use plastic ventilation ducts for drawing, then as the most suitable area of the duct section you need to take a value that is calculated by the formula a = 25s. At the same time, the flow rate should be equivalent to 3 meters per second. The letter "a" is the cross-sectional area expressed in square centimeters, while s is the air flow rate. These two values correlate with the constant (25). This indicates that 75 square centimeters are the most suitable cross-sectional area. If you use the course of school geometry and the formula (a = π × r²), then you can easily calculate the necessary dimensions. When choosing plastic ventilation ducts for drawing, you should prefer those that have a diameter of 2.8 cm. A certain length is also selected for this indicator. When using rectangular pipes, the calculation is made by a similar method. If the ventilation pipes are to be installed on the roof, and there is no possibility or desire to conduct calculations independently, then it is recommended to entrust these manipulations to specialists.

Features of the installation

It should be noted that the polymers do not have the qualities of fire resistance. In this case, you should use the combined mounting technology and additionally install the blowing fans, which contribute to the forced acceleration of air movement. Specialists who are engaged in the installation of ventilation systems, as a rule, use the method of combining galvanized metal and plastic. In this case, you can combine rectangular, round and other sections. Such solutions are used for the installation of extended systems that go from technical rooms and pass through places where a large number of people are clustered.

Here you can include restaurants, fitness centers and clubs. If ventilation pipes are installed on the roof, then the experience of consumers should be used. Thus, the most popular sections are those that refer to a range that is the limit of 55 to 110 millimeters. While the most often purchased pipes are those that have a length of 0.5 to 1.5 m.

Recommendations of the installation specialist

If in the process of laying the ductwork system, plastic ventilation ducts for exhaust ventilation will be used, it should be taken into account that the greatest efficiency can be achieved with the maximum straight line of the arrangement of the elements. If there are corners, the hardware costs will be increased, and the total amount of repairs will be quite impressive. When choosing the shape of the pipes, it is necessary to take into account that the rectangular cross section is able to withstand more air flow than the round one. And the technological process of fixing the docking involves more hassle.

Factors in favor of failure of plastic pipes before installation

If you want to use plastic pipes, the price of which is not so impressive in comparison with analog solutions, then before beginning the repair, it is necessary to familiarize yourself with all the minuses of the described material. Among the shortcomings can be identified low fire resistance, which is the main disadvantage. This characteristic significantly limits the scope of use. As a result, the ventilation system may not be accepted by fire services under the verification act. That is why plastic pipes are rarely used at production facilities. The use of this material is impractical for the transport of steam or excessively hot air. One can not but note the rather laborious installation, because the technology assumes that the master has the necessary skills and knowledge. Among other things, plastic pipes must be installed in tandem with special fittings and fittings. However, the most profitable is the plastic pipe. Pipes for stretching, the dimensions of which you can calculate by the above formula, correspond to the budget decision and allow you to reduce the cost of construction, without damaging the aesthetics of the building both inside and outside.

Nuances of mounting

Plastic pipes for extracting in the kitchen are used quite often. They can be painted in any color, and also to make an independent installation. As for the general duct system, the outlet provides for the installation of a steel pipe, the diameter of which should be 160 millimeters. This part needs to be supplemented with pipe outlets. Before connecting plastic pipes, it is necessary to take into account some recommendations for work. In accordance with the rules of fire and sanitary standards, the system can be equipped with a pumping and suction fan that can pull air masses. The use of a pipe with a diameter of 225 millimeters or more is advisable in the event that non-standard solutions take place. Here you can highlight the need to reckon with the technological or architectural features of a building, facility or a particular room. While solving such problems, engineering shortcomings and miscalculations may well be revealed, however, specialists are able to solve such questions quickly enough and for a moderate fee.

Selection of structural features of the pipe before installation of the system

If you use a profile plastic pipe , you need to choose the right diameter, which should not be less than the outlet hole at the outlet. Otherwise, the performance of the device will be reduced, the noise level will be higher, and the load on the engine will also increase. In this case, failure of the hood is possible. If the ventilation duct of the building has a diameter that is smaller than a similar characteristic characteristic of the exhaust holes, the whole sense of mounting the air duct of a more impressive diameter will be lost. When installing the pipe for drawing, remember that it should not be too curved and long. In the presence of a right angle, productivity is reduced by 10%.

Conclusion

With a more impressive bend, incorrect airflow can be triggered, as well as an overload of the motor. Plastic pipes, the price of which can start from 40 rubles per running meter, is the best solution for the duct system not in all cases.