In the conditions of the cold season, autonomous heating of the production premises provides the employees of the enterprise comfortable conditions for work. The normalization of the temperature regime also has a beneficial effect on the safety of buildings, machine tools and equipment. Heating systems, with the unity of the task facing them, have technological differences. Some use hot water boilers for heating industrial premises, while others use compact heaters. Consider the specifics of industrial heating and the effectiveness of the use of various systems.

Requirements for heating industrial premises

At low temperatures, heating of industrial premises, as required by labor protection, should be carried out in cases where the time spent by workers there exceeds 2 hours. The only exceptions are premises in which the permanent stay of people is not necessary (for example, rarely visited warehouses). Also, they do not heat structures, being inside of which is equivalent to carrying out work outside buildings. However, even here it is necessary to provide for the presence of special devices for heating workers.

Labor protection imposes a number of sanitary and hygienic requirements on the heating of industrial premises:

• heating indoor air to a comfortable temperature;
• the ability to regulate the temperature due to the amount of heat released;
• inadmissibility of air pollution with harmful gases and unpleasant odors (especially for furnace heating of industrial premises);
• the desirability of combining the heating process with ventilation;
• ensuring fire and explosion safety;
• reliability heating system during operation and ease of repair.

During non-working hours, the temperature in heated rooms can be reduced, but not below +5 °C. Wherein industrial heating should have sufficient power to start work shift time to restore normal temperature.

Mechanical ventilation - the standard for an energy efficient building

IN last years we pay more and more attention to the energy standard of the building in which it is built. These energy savings, in addition to the corresponding thermal insulation materials, use technologies and design solutions that reduce the building's energy consumption. The better the walls, roof and windows are insulated, the more the role of ventilation losses in the overall energy balance increases. The basis for reducing energy losses is supply and exhaust ventilation, which allows you to control the supply and exhaust of air from the room.

Calculation of autonomous heating of a production facility

When calculating the autonomous heating of a production facility, one proceeds from general rule that in the workshop, garage or warehouse a constant temperature should be maintained, without strong drops. For this, a central boiler room is being built, and heating radiators for industrial premises are installed in the working area. However, at some enterprises there is a need to create separate zones with unequal air temperatures. For the first of these cases, a calculation is made for the use of a central heating system, and for the second - for the use of local heaters.

In practice, the calculation of the heating system of the production room should be based on the following criteria:

• area and height of the heated building;
• heat loss through walls and roofs, windows and doors;
• heat loss in the ventilation system;
• heat consumption for technological needs;
• thermal power of heating units;
• the rationality of the use of a particular type of fuel;
• conditions for laying pipelines and air ducts.

Based on this, the need for heat energy is determined to maintain optimal temperature. More accurate calculation heating systems for industrial premises is facilitated by the use of special calculation tables. In the absence of data on the thermal properties of the building, the heat consumption has to be determined approximately according to specific characteristics.

When making a choice among various types of industrial heating systems, one should take into account the specifics of production, heat engineering calculations, the cost and availability of fuel, and build feasibility studies on this. Most closely match autonomous heating modern industrial premises of the system of infrared, water, air and electric types.

Infrared heating of industrial premises

To create the necessary thermal comfort in the workplace, infrared heating of industrial premises is often used. Infrared (IR) local heat emitters are mainly installed in workshops and warehouses up to 500 m² in area and with high ceilings. In each of these devices, a heat generator, a heater and a heat-releasing surface are structurally combined.

Advantages of infrared heating of industrial premises:

• there is only heating of the floor, walls, workshop equipment and directly the people working in the room;
• the air does not heat up, which means that the consumption of thermal energy is reduced;
• dust does not rise into the air, which is especially important for enterprises in the electronics, food industry and precision engineering;
• the cost of designing and installing heating is minimized;
• infrared heaters do not take up usable space.

Infrared heaters are divided into stationary and portable, and depending on the installation location, into ceiling, wall and floor. If it is necessary to influence individual workplaces, directional infrared radiation is used using small wall-mounted heaters. But if you mount film infrared heating on the ceiling of the production room, then the heating will be uniform over the entire area. Often they also arrange warm floors based on panels with built-in IR heaters, but with such a system, energy consumption increases.

Infrared gas heating of industrial premises is also used at enterprises. These heaters are fueled by natural gas, which is cheaper than electricity. The main advantage of gas infrared emitters is their efficiency.

Radiators for infrared gas heating systems for industrial premises are available in several types:

• high-intensity (light) with a heat transfer temperature of 800–1200 °C;
• low-intensity (dark) with a temperature of 100–550 °C;
• low-temperature with a temperature of 25–50°C).

A limitation in the use of industrial IR heaters is the requirement not to place them in rooms with a ceiling height of less than 4 m.

Water heating of industrial premises

If the enterprise will use a water heating system, for its installation it is necessary to build a special boiler room, lay a piping system and install heating radiators in industrial premises. In addition to the main elements, the system also includes means of ensuring operability, such as shut-off valves, pressure gauges, etc. To service the water heating system of industrial premises, it is necessary to constantly maintain special personnel.

Based on your device water heating industrial premises are:

• one-pipe- regulation of the water temperature is not possible here, since all heating radiators for industrial premises are installed in series;
• two-pipe- temperature regulation is permissible and is carried out using thermostats on radiators installed in parallel.

Heating boilers serve as heat generators for the water heating system. According to the type of fuel consumed, they are: gas, liquid fuel, solid fuel, electric, combined. For heating small industrial premises, furnaces with a water circuit are used.

It is necessary to choose the type of boiler based on the needs and capabilities of a particular enterprise. For example, the ability to connect to a gas main will be an incentive to purchase a gas boiler. In the absence of natural gas, a diesel or advanced solid fuel unit is preferred. Electric heating boilers for industrial premises are used quite often, but only in small buildings.

At the height of the heating season, failures or accidents in gas and electricity supply systems can occur, so it is advisable to have an alternative heating unit at the enterprise.

Industrial premises are much more expensive, but they are equipped with several types of burners: G Azov-wood, gas-diesel, and even gas-diesel-electricity.

Air heating of industrial premises

The air heating system at each specific industrial enterprise can be used as the main one, or as an auxiliary one. In any case, the installation of air heating in the workshop is cheaper than water heating, since it is not necessary to install expensive boilers for heating industrial premises, lay pipelines and mount radiators.

Advantages of the air heating system of the industrial premises:

• space saving working area;
• energy efficient consumption of resources;
• simultaneous heating and air purification;
• uniform heating of the room;
• safety for the well-being of employees;
• no risk of leaks and freezing of the system.

Air heating of a production facility can be:

• central- with a single heating unit and an extensive network of air ducts through which heated air is distributed throughout the workshop;
• local- air heaters (air-heating units, heat guns, air-heat curtains) are located directly in the room.

In the centralized air heating system, to reduce energy costs, a recuperator is used, which partially uses the heat of the internal air to heat the fresh air coming from outside. Local systems do not carry out recuperation, they only warm the internal air, but do not provide an inflow of external air. Wall-ceiling air heaters can be used for heating individual workplaces, as well as for drying any materials and surfaces.

By giving preference to air heating of industrial premises, business leaders achieve savings due to a significant reduction in capital costs.

Electric heating of industrial premises

When choosing the electric heating method, two options for heating workshops or warehouses should be considered:

• using electric heating boilers for industrial premises;
• using portable electric heaters.

In some cases, it may be advisable to install small electric furnaces for heating industrial premises with a small area and ceiling height.

Electric boilers have an efficiency of up to 99%, their operation is fully automated due to the presence of a programmable control. In addition to performing the heating function, the boiler can serve as a source of hot water. Absolute purity of air is ensured, since there is no emission of combustion products. However, the numerous advantages of electric boilers are crossed out by the too high cost of the electricity they consume.

Electric convectors can successfully compete with electric boilers in the field of industrial premises heating. There are electric convectors with natural convection, as well as with forced air supply. The principle of operation of these compact devices is the ability to heat rooms by heat exchange. The air passes through the heating elements, its temperature rises, and then it completes the normal cycle of circulation inside the room.

Disadvantages of electric convectors: they dry out the air excessively, they are not recommended for heating rooms with high ceilings.

Heating radiant panels in a relatively short time managed to demonstrate their excellent energy-saving characteristics. Outwardly, they are similar to convectors, but their difference is manifested in the special design of the heating element. The advantage of electric radiant panels is their ability to act on objects in the room without needlessly heating the air. Automatic thermostats help maintain the set temperature.

Whichever of the heating systems of the production premises the owner of the company decides to install, his main task should be to take care of maintaining the health and performance of all the company's personnel.

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SANITARY DESIGN STANDARDS FOR INDUSTRIAL ENTERPRISES - SN 245-71 (approved by Decree of the USSR State Construction Committee dated 05-11-71 179) (2017) Actual in 2017

5. Requirements for heating, ventilation and air conditioning

5.1. The design of heating, ventilation and air conditioning of industrial buildings and structures of enterprises, as well as ventilation air emissions into the atmosphere and its purification before release, should be carried out in accordance with the requirements of these Norms and the chapter of SNiP on the design of heating, ventilation and air conditioning.

5.2. Ventilation, heating and air conditioning of industrial buildings and structures (including crane cabins, control panels rooms, etc. isolated rooms) should be designed to provide meteorological conditions at permanent workplaces and in the working area during the main and maintenance and auxiliary works ( temperature, relative humidity and speed of air movement), as well as the content of harmful substances in the air in accordance with the requirements of sections 10 and 11 of these Norms.

5.3. In rooms with heat emissions, it is allowed to provide for the use of excess heat for heating and ventilation, taking into account the requirements of paragraphs 5.14 - 5.17 of these Norms.

5.4. The amount of air required to provide the required parameters of the air environment in the working area should be determined by calculation, taking into account the uneven distribution of harmful substances, heat and moisture along the height of the room and in the working area:

a) for rooms with heat release - by excess sensible heat;

b) for rooms with heat and moisture release - by excess sensible heat, moisture and latent heat, with a check to prevent moisture condensation on the surfaces of building structures and equipment, taking into account the requirements of clause 3.13 of these Standards;

C) for premises with gas emissions - by the amount of harmful substances released, from the condition of ensuring maximum permissible concentrations.

Notes. 1. The amount of industrial hazardous substances released into the premises, heat and moisture should be taken according to the technological part of the project or the technological design standards.

2. In the absence of data on the amount of industrial hazards released into the premises in the technological part of the project or the norms of technological design, they can be determined according to field surveys of similar enterprises or sanitary and hygienic characteristics indicated in the passports of the enterprise adopted in the project technological equipment, as well as through calculations.

3. With the simultaneous release of harmful substances, heat and moisture into the premises, the amount of supply air in the design of ventilation should be taken larger, obtained from the calculations for each type of industrial emissions.

5.5. It is not allowed to determine the amount of air for ventilation by the frequency of air exchange, except as specified in normative documents agreed and approved in the prescribed manner.

5.6. Emissions into the atmosphere of air removed by general ventilation, containing harmful and unpleasantly smelling substances through concentrated devices (pipes, shafts, deflectors) or through dispersed devices (opening lantern openings, window transoms and other openings), and the calculation of the dispersion of these substances should be provided as follows: so that their concentrations do not exceed:

a) in atmospheric air settlements - the maximum one-time, specified in section 9 of these Regulations.

Note. In the absence in the table. 3 values ​​of the maximum one-time concentrations of harmful substances should be taken when calculating the dispersion of the average daily concentrations indicated in this table as the maximum one-time.

B) in the air entering buildings and structures through the intake openings of ventilation and air conditioning systems and through openings for natural supply ventilation, - 30% of the maximum permissible concentrations of harmful substances in the working area of ​​industrial premises specified in Section 10 of these Regulations.

5.7. The air removed by local exhausts and containing dust or harmful and unpleasantly smelling substances is subject to cleaning before being released into the atmosphere to meet the requirements of clause 2.15, taking into account the requirements of clauses 5.6 and 5.8 of these Norms, the chapter of SNiP on the design of heating, ventilation and air conditioning air, as well as industry regulations approved in the prescribed manner.

For the residual content of harmful substances in ventilation emissions during incomplete purification, as well as in the absence of technical means of purification, it is necessary to provide for the dispersion of harmful substances in the atmospheric air in compliance with the same requirements.

With an insignificant gross amount of ventilation emissions containing harmful substances or their low concentration in the emitted air, it is allowed not to provide for its purification, if by dispersing harmful substances in the atmospheric air under the most unfavorable conditions for the area (direction and strength of winds, precipitation, pressure, etc.) .p.) the above requirements will be met.

In the absence of technical means for cleaning the exhaust air, it is recommended to provide for the possibility of building cleaning devices at the enterprise in the future.

5.8. In calculations of atmospheric air pollution generated by ventilation emissions in settlements and on the territory of enterprises, it is necessary to take into account the maximum total emissions of harmful substances in the ventilation air, the concentrations of these substances in the atmospheric air from technological emissions according to the technological part of the projects and the background (existing) concentrations of harmful substances in construction area, information about which should be obtained from the bodies of the sanitary and epidemiological service of the USSR Ministry of Health and the Main Hydrometeorological Service.

Note. The calculation of dispersion in the atmosphere of harmful substances contained in ventilation emissions is carried out as part of the ventilation project of the enterprise.

5.9. In industrial premises with a volume per worker of less than 20 cubic meters. m should design the supply of outdoor air in an amount of at least 30 cubic meters. m / h for each worker, and in rooms with a volume of more than 20 cubic meters per worker. m - not less than 20 cubic meters. m/h for each worker.

In rooms with a volume of more than 40 cubic meters per worker. m in the presence of windows or windows and lanterns and in the absence of the release of harmful and unpleasantly smelling substances, it is allowed to provide for periodically operating natural ventilation (opening the sashes of windows and lanterns).

When designing buildings, industrial premises and their separate zones (sections) without natural ventilation (ventilation) with only outside air supplied to them by means of mechanical ventilation, the volume of outside air must be at least 60 cubic meters. m/h per worker, but not less than a single air exchange (over the entire volume of the room) in 1 hour.

When using mechanical ventilation and air conditioning systems with recirculation for these buildings, industrial premises and their individual zones, the volume of outdoor air supply must be at least 60 cubic meters. m/h per worker, but not less than one air exchange per hour with an estimated air exchange rate of 10 or more.

With a lower calculated air exchange rate (and the use of recirculation), the volume of outdoor air supply must be at least 60 cubic meters. m/h per worker, but not less than 20% of the total air exchange.

Notes. 1. If the calculated air exchange rate is less than 10 and recirculation is used, it is allowed to reduce the volume of outdoor air supply to 10%, if it is planned to supply more than 120 cubic meters per worker. m/h of outside air.

2. Buildings and premises without natural ventilation should include buildings and premises in which supply of fresh air is designed only by means of mechanical ventilation, without special openings for aeration. Zones (areas) of premises without natural ventilation should also include zones (areas) of aerated premises located at a distance of more than 30 m from external walls with aeration openings.

3. The "absence of emission of harmful substances" should be understood as such a quantity of them in the process equipment, with the simultaneous release of which into the air of the premises, the concentration of harmful substances in it will not exceed the maximum allowable limits established for the working area.

5.10. general exchange supply and exhaust ventilation rooms without natural ventilation should be designed, providing for at least two supply and two exhaust ventilation units with a capacity of each of at least 50% of the required air exchange. It is allowed to design one supply and one exhaust unit, equipped with a backup fan, which turns on automatically when the operating one stops. Blocking is also allowed. ventilation systems of this room with systems serving neighboring rooms to ensure at least 50% of the required air exchange when the main system fan stops.

5.11. If, according to the technology, isolated rooms without natural ventilation for the period of shutdown of supply or exhaust general ventilation can be connected to adjacent rooms by openings that provide sufficient suction or air displacement, then for such rooms it is allowed not to provide backup fans specified in clause 5.10 of these Standards, and to have the necessary stock to replace failed fans during the day.

5.12. An unorganized inflow of outside air to compensate for the exhaust during the cold season when designing ventilation can be taken in the amount of no more than a single air exchange per 1 hour. internal surfaces external walls, coatings and glazing of openings, the angle of inclination of which to the horizon is less than 55 degrees.

5.13. It is allowed to provide for the intake of air from adjacent rooms if no harmful and unpleasantly smelling substances are emitted in them or if harmful substances belong to hazard class 4 and their content in the incoming air does not exceed 30% of the maximum permissible concentrations in the air of the working area.

At the same time, it is necessary to provide for the balance of air according to the organized supply and exhaust in adjacent rooms interconnected by ventilation and compliance with the requirements of these Standards for air purity.

Note. Device exhaust ventilation with mechanical stimulation, not compensated by organized air flow, in buildings and structures with furnace heating not allowed.

5.14. When designing ventilation and air heating, it is allowed to provide for air recirculation during the cold and transitional periods of the year.

For air conditioning systems, it is allowed to provide air recirculation at all times of the year.

When using air recirculation, the amount of outdoor air supplied to each worker must comply with the requirements of clause 5.9 of these Standards.

5.15. The use of recirculation for air heating, not combined with ventilation, is allowed to be provided within the same room, if there are no emissions of harmful substances that sublimate when in contact with the heated surfaces of process equipment and air heaters of the air heating system.

5.16. For recirculation, it is allowed to use the air of rooms in which there are no emissions of harmful substances or if the emitted substances belong to hazard class 4 and the concentration of these substances in the air supplied to the room does not exceed 30% of the maximum permissible concentrations. In this case, the requirements of paragraph 5.17 of these Regulations must be taken into account.

It is allowed to provide for the operation of supply systems for recirculation during non-working hours, if the possibility of residual emissions of harmful substances of hazard classes 1 and 2 is excluded in the premises.

5.17. The use of air recirculation for ventilation, air heating and air conditioning is not allowed to be provided in the premises:

a) the air of which contains pathogenic bacteria, viruses and fungi;

b) in which there are pronounced unpleasant odors;

C) in the air of which harmful substances of 1, 2 and 3 hazard classes are released.

Note. Air recirculation may be provided for in cases where the amount of harmful substances in the process equipment is such that, if they are simultaneously released into the room air, the concentrations in it will not exceed the maximum allowable limits established for the working area.

5.18. For rooms in which a local increase in temperature and speed of movement of the supply air can lead to an increase in the concentration of harmful substances in the air of the working area above the prescribed norms, it is necessary to provide for measures in the devices of supply ventilation, air heating and air conditioning systems that exclude the possibility of increasing the concentration of harmful substances in indoor air.

5.19. The supply of supply air to ventilated premises with natural ventilation should, as a rule, be provided for in the warm season at a level of no more than 1.8 m and in the cold season - at least 4 m from the floor to the bottom of the ventilation openings.

The supply of unheated air during the cold season at lower elevations is allowed, provided that measures are taken to prevent direct exposure to cold air on workers.

5.20. The temperature and speed of air discharge from the air distributors of ventilation, air conditioning and air heating systems should be determined by calculation in order to ensure that the working area is provided with weather conditions in accordance with section 11 of these Regulations.

5.21. Air or air-thermal curtains (air curtains with air heating) should be provided at gates that open more than five times or for at least 40 minutes. per shift, as well as at technological openings of heated buildings and structures under construction in areas with an estimated outdoor air temperature for heating design - 15 degrees. C and below, in the absence of tambours-locks, as well as with appropriate justification and at higher design outdoor temperatures and for any duration of opening gates and other openings.

5.22. Air and air-thermal curtains should be designed so that at the time of opening the gates, doors of technological openings, the air temperature in the premises at permanent workplaces is not lower than:

A) 14 degrees. C with light physical work;

b) 12 deg. C for moderate work;

c) 8 deg. C for hard work.

In the absence of permanent jobs near the gates, doors and technological openings, it is allowed to lower the air temperature in this zone when they are opened to 5 degrees. C.

The temperature of the air mixture passing through the gates, technological openings and doors should not be lower than the air temperatures specified in this clause.

5.23. Combining into a common exhaust unit suction of dust and easily condensing vapors, as well as substances that, when mixed, can create harmful mixtures or chemical compounds, is not allowed.

5.24. Local exhausts that remove hazardous substances of hazard classes 1 and 2 from process equipment should be blocked with this equipment in such a way that it cannot work if local exhaust ventilation is inactive.

If it is not possible to stop the production process when the local exhaust ventilation is turned off, or when the equipment (process) is stopped, the release of harmful substances into the indoor air in quantities exceeding those specified in Note 3 to Clause 5.9 of these Standards continues, then provision should be made for the installation of backup fans for local exhausts with automatic switching them.

5.25. Emergency ventilation should be provided in accordance with the norms of technological design and the requirements of departmental regulatory documents approved in the prescribed manner in industrial premises in which a sudden release of large amounts of harmful substances (except dust) into the air of the working area is possible. Emergency ventilation should be designed in accordance with the requirements of the SNiP chapter on the design of heating, ventilation and air conditioning, as well as other regulatory documents approved in the prescribed manner.

If departmental regulatory documents do not contain instructions on emergency ventilation air exchange, then it should be provided that, together with permanent ventilation, it provides air exchange in the room, if necessary, at least 8 exchanges per 1 hour according to the internal volume of the room.

5.26. Emergency ventilation should, as a rule, be provided by exhaust.

Air removal by emergency ventilation (exhaust and supply) should be provided outside.

Compensation for the air removed by emergency exhaust ventilation should be provided mainly due to the intake of air from outside.

5.27. Ejection openings of emergency ventilation should not be located in places of permanent residence of people and placement of air intake devices of ventilation and air conditioning systems.

5.28. The projects should, as a rule, provide for blocking emergency ventilation with gas analyzers tuned to allowable concentrations of harmful substances.

In addition, the start of fans and the opening of openings for the removal of air by emergency ventilation should, as a rule, be designed remotely from accessible places both inside and outside the premises.

5.29. Heating, ventilation and air conditioning installations should not create permanent workplaces in industrial buildings and in the serviced area of ​​auxiliary buildings, noise exceeding the permissible sound pressure levels, and vibration exceeding those established by these Standards.

5.30. In tunnels intended for periodic work or movement of people, as well as in rooms of technical floors, natural or artificial ventilation with calculated air exchange.

5.31. For heating buildings and structures of enterprises, systems, devices and heat carriers that do not create additional production hazards should be provided.

5.32. The use of radiant heating with infrared gas emitters is allowed to be provided with the complete removal of combustion products into the atmosphere (outside).

5.33. Heating systems should be provided with control devices for rooms in which a change in heat transfer is necessary.

5.34. When permanent workplaces are located near windows, protection of workers from falling cold air flows should be provided.

5.35. In panel heating systems average temperature heating surface should be provided not higher than:

a) on the heating surface of the floor - 26 degrees. C, with the exception of floors in lobbies and other rooms with temporary stay of people, where the temperature on the heated floor surface can be provided up to 30 degrees. C;

b) on the heating surface of the ceiling at the height of the room:

2.5 - 2.8 m - 28 deg. C;

2.9 - 3.0 m - 30 deg. C;

3.1 - 3.4 m - 33 deg. C;

C) on the heating surface of partitions and walls at a height of up to 1 m from the floor level - 95 degrees. C, and above 1 to 3.5 m - 45 degrees. C.

5.36. Heating devices in industrial premises with significant dust emissions should be provided with smooth surfaces that allow easy cleaning.

5.37. Placement of supply heating and ventilation equipment, air conditioners serving rooms in which air recirculation is not allowed should be provided in isolated rooms.

When designing exhaust ventilation systems, measures should be taken to prevent the penetration of exhaust air into the supply air. ventilation units, air conditioners, in rooms intended for ventilation equipment, and in production rooms.