Duct heaters of air: advantages and disadvantages

The modern realities of life in our country are by no means high technologies. Today, many countries live in a constantly growing cost of energy. The issues of saving energy resources are very relevant, and this applies to absolutely any branch of the national economy. No exception, and the energy that is spent for heating residential and non-residential premises. SNiP rigidly and clearly regulates the parameters by which air exchange should be carried out in different rooms, however, along with the outflow of air through the ventilation system, precious heat also leaves.

Partly, it is possible to compensate for heat loss by recuperative installations, but their efficiency is far from ideal and does not allow replenishing heat losses. One of the most effective options for creating and maintaining an optimal microclimate in the room are channel heaters. These are additional devices that supply ventilation systems.

Excursion to the history

This system is by no means a new development. The first such heater was designed, designed, and then created by A.A. Ammosov in 1835. It was then that the first channel heaters began to be installed in the halls of the Imperial Art Academy in St. Petersburg. The effectiveness of one such solution was equated to 30 elements, minimally reminiscent of modern central heating systems. Later these heaters were also used to heat the Winter Palace. However, for all their efficiency and high productivity, these air furnaces had a number of significant disadvantages. So, in the process of working equipment constantly produced a strong rumble and noise. If it was raining with a thunderstorm, or pressure drops were observed, then it caused a crack in the channels of the ventilation system. And finally, the hot air, passing through the ventilation duct, greatly overheated these very channels, which did not have the best effect on the interiors of the royal halls.

It is because of overheating from such air furnaces that they refused. The last heater was removed in 1912. And although this device did not justify the hopes, the whole idea was not abandoned, and today channel heaters are widely used in various ventilation systems of residential, non-residential and industrial buildings.

Electrical equipment

Channel heating systems of this type are designed for heating air in ventilation equipment and in air conditioning solutions. Also these devices are widely used in the composition of drying plants. Duct heater electric is the key equipment in heating or anti-icing, HVAC, secondary heating systems. Industrial solutions are powerful complexes that meet high safety standards. This is very important for most branches of modern industry - oil refining, gas, chemical.

Design feature

There are several heating elements in the complex. They are made mainly of high-quality stainless steels. In order to avoid contact of the heating elements, they are separated by means of special plates. This makes it possible 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. Areas of application are mainly ventilation systems with round air ducts. The duct heater is ideal for use in a room ventilation system with a large enough area. It can be various exhibition halls and complexes, production halls, shopping centers, waiting rooms.

Operating principle

The heating element is used as the main element in the form of a spiral. Air flowing through the supply ventilation system passes through the heaters, which give it some of its heat, and then through the ventilation system enters the room. To ensure that the equipment can work throughout its life, many manufacturers recommend the use of duct heaters along with a mechanical filter - the air must be as clean as possible. For sale, you can find various models that connect to a common ventilation system. In turn, the software that controls the ventilation should also include the heater control functions.

It is mandatory to provide software protection against overheating. However, many modern models have built-in protection in case of overheating. It is realized by means of bimetallic thermoswitches. There are two of them - one of them is designed for triggering at 70 degrees, the other is designed to respond in the event of a fire and fires 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 temperature from 0 to 30 degrees above zero, while the humidity is up to 80%. As for the maximum possible heating, the air output is 40 degrees.

Water heaters

The water channel heater has a lot of fundamental differences from electrical equipment. As for the destination, they are recommended to install in rectangular ventilation. However, modern enterprises offer a wide range of models for round channels.

The device and the principle of operation

The water channel heater is a housing made of galvanized or stainless steels. Inside it, the links of the empty inside the coil of copper or copper alloys are staggered. Also in the device of water heater there are aluminum plates, which are intended for heat release. The heated coil moves in the copper coil. It can be water or a glycol solution. Heat, which is given through the circulation of the liquid, goes to the aluminum plates, and they transmit heat to the air from the supply system already.

A rectangular duct heater will be used for a long time and efficiently only if there is a filter in the line that cleans incoming air. In the latter there should be no abrasive elements, aggressive substances and other impurities. Possible operating temperatures range from 5 to 60 degrees. In order for the heater to operate with maximum efficiency, the pressure in the ventilation system must be at least 1.5 mPas. Often, a ducted air heater, operating on this principle, does not have its own autonomous control system. The capacity of the unit is regulated by external devices. These are throttling cranes, by means of which it is possible to change the speed of circulation of liquid in the circuit. The valve opens or closes the circulation, the mixing unit allows you to regulate the amount of incoming and outgoing 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 possibility to use channel heaters for round channels. Among the minuses of electric models it is worth noting the great inertia in the filament spirals. Because of this, the equipment quickly overheats. Also a significant drawback - the cost of operation. The cost of electricity will be significantly higher compared to water solutions.

The liquid channel air heater is the most popular solution for most ventilation systems. Water moves in a rectangular direction, opposite to the air flow.

Summary

A ducted air heater, or air heater - is an inexpensive and efficient heating solution, which allows you to save considerably on energy resources and at the same time maintain a microclimate in all types of premises.