the controlled exchange of air in an area; also, the equipment and installations creating such an exchange. Ventilation is designed to provide the necessary purity, temperature, humidity, andcirculation of air. These requirements are determined by health standards: the presence of noxious substances in the air (gases, vapors, or dust) is restricted to permissible concentrations(those which are harmless to human health); and the temperature, humidity, and circulation of the air are determined in relation to the conditions required for optimum human comfort. For manyindustrial areas (shops for the assembly of precision instruments, radio-electronics equipment, and so on), air purity, temperature, and humidity are also determined by the special requirementsof the technological processes involved. In a number of cases (museum storage facilities, archives, or warehouses) the air temperature and humidity in an area must correspond to theconditions required for the best preservation of objects and materials, equipment, or construction components contained in it.
In industrial areas, the principal source of emission of noxious substances, heat, and moisture is the technological process taking place within the area. In residential dwellings, these emissionsoccur primarily in lavatories and kitchens, especially during the use of gas ranges. The activity of the human organism is also accompanied by the emission of noxious substances (carbondioxide), odors, heat, and moisture. The preparation of food, bathing, and the washing of dishes and clothing raise the temperature and humidity of room air and increase its dust content andbacterial contamination (particularly if sick persons are present). All of these substances may be removed by means of ventilation. In cases of pollution of the air basin (for example, by exhaustfumes from automobile traffic or industrial discharges), noxious substances may enter room areas with the outside air.
Solar radiation (chiefly through windows) and artificial lighting are sources of additional heat accumulation. The reduction of emissions of noxious substances and of excess heat and moisture isan important factor in improving the condition of the air in industrial environments, and it also creates more favorable conditions for the operation of ventilation. Nontoxic or low-toxicity materialsare used for these purposes in industrial processes, production equipment and distribution supply lines are hermetically sealed, and surfaces that give off heat are covered with thermalinsulation. The reduction of excess heat is achieved by the use of window-mounted sun protection devices, heat-absorbing glass, the use of forced heat-dissipation lamps for lighting, and othermethods. Current health standards in the USSR specify that the air of living spaces must be as follows (during the winter season): temperature, 18°–22° C; relative humidity, 40-60 percent;circulation, 0.1-0.2 m/sec; and maximum C02 content, 0.1 percent. Noxious gas contaminants are not permitted in the air.
A distinction is made between forced, exhaust, suction-and-exhaust, general-exchange, local, natural, and mechanical types of ventilation.
In industrial areas, the principal source of emission of noxious substances, heat, and moisture is the technological process taking place within the area. In residential dwellings, these emissionsoccur primarily in lavatories and kitchens, especially during the use of gas ranges. The activity of the human organism is also accompanied by the emission of noxious substances (carbondioxide), odors, heat, and moisture. The preparation of food, bathing, and the washing of dishes and clothing raise the temperature and humidity of room air and increase its dust content andbacterial contamination (particularly if sick persons are present). All of these substances may be removed by means of ventilation. In cases of pollution of the air basin (for example, by exhaustfumes from automobile traffic or industrial discharges), noxious substances may enter room areas with the outside air.
Solar radiation (chiefly through windows) and artificial lighting are sources of additional heat accumulation. The reduction of emissions of noxious substances and of excess heat and moisture isan important factor in improving the condition of the air in industrial environments, and it also creates more favorable conditions for the operation of ventilation. Nontoxic or low-toxicity materialsare used for these purposes in industrial processes, production equipment and distribution supply lines are hermetically sealed, and surfaces that give off heat are covered with thermalinsulation. The reduction of excess heat is achieved by the use of window-mounted sun protection devices, heat-absorbing glass, the use of forced heat-dissipation lamps for lighting, and othermethods. Current health standards in the USSR specify that the air of living spaces must be as follows (during the winter season): temperature, 18°–22° C; relative humidity, 40-60 percent;circulation, 0.1-0.2 m/sec; and maximum C02 content, 0.1 percent. Noxious gas contaminants are not permitted in the air.
A distinction is made between forced, exhaust, suction-and-exhaust, general-exchange, local, natural, and mechanical types of ventilation.
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