Exhaust systems are organized predominantly decentralized. Sometimes, however, may restrict only two systems: for the trading floor for the entire group of industrial buildings, except for restrooms and showers. The latter, in this case is naturally ventilated. Exhaust fans are installed in isolated areas - in attics, a special technical floor or insulated booths outside a building. The latter may be permitted only as an exception when an indispensable sound isolation booths.
Toilets and showers in all cases must be serviced self-hood with natural or mechanical drive.
Air balance premises catering, as a rule, should be positive: the total amount of fresh air more than the total extract. This is necessary in order to avoid suction of cold and unfiltered air from outside, as well as to prevent air from adjacent spaces. The latter is particularly important for industries where close to the dining room can be arranged with the guilds of harmful emissions.
Only in some rooms catering should be allowed to balance the positive air-flow prevails over the hood in the sales rooms, in lobbies, in the boot. In other areas the air balance is negative.
Part of the fresh air needed to compensate for the extraction and the creation of the overall positive balance, served in the hallways, lobbies, stairwells and other areas without hazards.
Ventilation systems catering located in industrial buildings should not be combined with the ventilation systems of these buildings.
In catering hazards are heat, moisture, gases and odors. Pylsvydeleniya virtually absent.
The main hazards, determining the value of air is excess heat from stoves and cooking equipment, tools, hot food, people, lighting and solar radiation. Vlagovydeleniya less important. Water vapor released from the hot food digesters, people and washing equipment. Gases, mostly acrolein, enter the premises when frying in hot fat, as well as for baking pastries. Smells accompany almost all processes of cooking. A special place is occupied by the evaporation of raw onions - not only fragrant, but also irritates mucous membranes.
Ventilation is performed with local suction and general exchange. Local suction in the form of veil or annular duct above the cooker is found everywhere. Local pumps are also needed from elektroskovorodok fryers and frying pies, pastry ovens, dishwashers and lukorezok. Listed exhaust local pumps in catering. Rarely satisfied with the veil over the digesters, as well as the gap pumps from hand washing. The latter should be welcomed, since fricatives pumps eliminate working at car washes from the need to inhale water vapor contaminated with lye soap.
Air in the major production areas - kitchens and other hot shops, as well as in washing - is determined by calculating how the performance of local suction and to remove excess heat. Checking the air to remove moisture is usually not performed as well as air, determined from the heat and local suction, appears to be sufficient to remove moisture. Gases are removed local suction - curtains, umbrellas, slotted suction; check general ventilation on the gas removal is not performed.
In the trading rooms of air is determined by calculation of excessive heat. Checking for vlagoudalenie also not required.
In other production areas, except for washing, ventilation and general exchange is determined by the multiplicity of exchange. As well appointed air and supporting facilities.
Featured multiplicity of exchange leads 87-50 in CH as in the supply and exhaust ventilation and the presence of only the hood. Multiplicity of exchange for the first case should
recognize the minimum necessary, provide relatively favorable conditions. Reduce air exchange during the absence of an organized flow should not be, especially for the summer. Exhaust ventilation should be designed according to uniform standards regardless of how the fresh air supply. In the cold season in the absence of the flow of heated exhaust can be reduced accordingly.