Modern realities of life in our country are by no means high technologies. Today, many countries live in an ever-increasing cost of energy. The issues of saving energy resources are very relevant, and this applies to absolutely any sector of the national economy. The energy used for heating residential and non-residential premises is no exception. SNiP strictly and clearly regulates the parameters by which air exchange in various rooms should be carried out, however, together with the outflow of air through the ventilation system, precious heat also leaves.
Partially, heat loss can be compensated for by recovery units, however, their efficiency is far from ideal and does not allow to compensate for heat losses. One of the most effective options for creating and maintaining an optimal indoor microclimate is duct heaters. These are additional devices that complete the supply ventilation systems.
History tour
This system is by no means a new development. The first such heater was developed, designed, and then created by Ammosov N.A. in 1835. It was then in St. Petersburg that the first channel heaters began to be installed in the halls of the Imperial Academy of Art. The effectiveness of one such solution was equated to 30 elements, minimally resembling modern central heating systems. In the future, these heaters began to be used to heat the Winter Palace.
However, with all its efficiency and high productivity, these air furnaces had a number of significant drawbacks. So, in the process, the equipment constantly emitted a strong hum and noise. If it rained with a thunderstorm, or pressure drops were observed, then this provoked a crack in the channels of the ventilation system. And finally, hot air, passing through the
ventilation duct, overheated these very channels, which did not have the best effect on the interiors of the royal halls.
It was because of overheating that they abandoned such air furnaces. The last heater was removed in 1912. And although this device did not meet expectations, they did not completely abandon the idea, and today duct heaters are widely used in various ventilation installations of residential, non-residential and industrial premises.
Electrical equipment
Channel heating systems of this type are designed to heat air in ventilation equipment and in air conditioning solutions. Also, these devices are widely used in drying plants. An electric duct heater is a key equipment in heating or anti-icing systems, HVAC, and secondary heating installations.
Industrial solutions are powerful systems that meet high safety features. This is very important for most sectors of modern industry - oil refining, gas, chemical.
Design feature
The complex includes several heating elements. They are made primarily of high quality stainless steels. In order to exclude contact of the heating elements, they are separated using special plates. This allows you to increase the reliability, as well as the service life and safety of the entire heater. The case is made of stainless or galvanized steel. The system is manufactured with protection class IP43. Fields of application are mainly ventilation systems with round ducts. The electric duct heater is ideally suited for use in a ventilation system of rooms with a sufficiently large area. It can be various exhibition halls and complexes, production shops, shopping centers, waiting rooms.
Operating principle
As the main element, heating elements in the form of a spiral are used. The air supplied through the supply ventilation system passes through the heaters, which give him part of their heat, and then through the ventilation system enters the room.
In order for the equipment to work during its entire service life, many manufacturers recommend operating duct heaters together with a mechanical filter - the air must be as clean as possible. On sale you can find various models that are connected to a common ventilation complex. In turn, the ventilation control software must also include heater control functions.
Be sure to provide software protection against overheating. However, many modern models have built-in protection in case of overheating. It is implemented by means of bimetallic thermal switches. There are two of them - one of them is designed to operate at 70 degrees, the other is designed to respond in case of fire and works at 130 degrees. For normal operation of the heater, the air flow must be supplied at a speed of at least 2 m / s. These devices are designed for air temperatures from 0 to 30 degrees above zero, while the humidity is up to 80%. As for the maximum possible heating, the outlet air is 40 degrees.
Water heaters
Water channel heater has a lot of fundamental differences from electrical equipment. As for the purpose, they are recommended to be installed in rectangular ventilation. However, modern enterprises offer a wide selection of models for round channels.
Device and principle of operation
The water channel heater is a housing made of galvanized or stainless steel. Inside it, the links of the empty coil made of copper or copper alloys are necessarily staggered. Also in the device of the water heater there are aluminum plates that are designed to transfer heat. A heated fluid moves in a copper coil. It can be water or glycol solution. The heat that is given through the circulation of the fluid goes to the aluminum plates, and they transfer heat already to the air from the supply system.
A rectangular duct heater will be used for a long time and effectively only if there is a filter in the line that cleans the incoming air. The latter should not contain abrasive elements, aggressive substances and other impurities. Possible operating temperatures range from 5 to 60 degrees. For the heater to operate with maximum efficiency, the pressure in the ventilation system must be at least 1.5 MPa. Often, a ducted air heater operating on this principle does not have its own autonomous control system. Unit performance is regulated by external devices. These are throttle valves with which you can change the rate of fluid circulation in the circuit. The valve opens or closes the circulation, the mixing unit allows you to adjust the amount of incoming and returning working fluid.
Advantages and disadvantages
The operation of electric heaters is accompanied by only slight pressure drops. It is very easy for them to calculate the required power. Also among the advantages: wide availability, reasonable cost, ease of installation, the ability to use duct heaters for round channels. Among the minuses of electric models, it is worth noting the large inertia in the incandescent spirals. Because of this, the equipment quickly overheats. Also a significant drawback is the operating costs. Electricity costs will be significantly higher compared to water solutions.
A liquid duct air heater is the most popular solution for most ventilation systems. Water moves in a rectangular direction opposite to air flow.
Summary
A duct air heater, or air heater, is an inexpensive and effective solution for heating, which can significantly save energy and at the same time maintain a microclimate in all types of rooms.