From Big Medical Encyclopedia

MICROCLIMATE (Greek mikros small + climate) — the complex of physical environmental factors in limited space exerting impact on thermal exchange of an organism.

The m is defined by the key physical parameters: temperature, speed of the movement and air humidity, temperature of surrounding surfaces and radiant energy. Atmospheric pressure has essential value only in special conditions of activity of the person (aircraft, lacunar works, works in mountains, etc.).

M of rooms is affected by seasonal, external climatic conditions, to-rye are very various — from roast to a severe, frigid climate. Therefore at design of buildings of different function climatic conditions of a certain region are considered. The m of rooms in essence is artificial, and the person can actively influence his parameters. The m of the open areas — natural is also defined by influence of climate of the area on vital processes of the person.

The heatfeeling of the person under the influence of M. of the environment is fiziol, the reaction protecting an organism from disturbance of a heat balance and induces to take necessary measures of protection in case of its disturbance. Thermal exchange of the person is defined by relationship between formation of heat as a result of exchange reactions of substances and return or obtaining heat from the environment. Studying of heat exchange of the person in various conditions of M. allowed to develop a dignity. M.'s norms to define degree of adaptation of an organism and to develop measures of protection from excessive influence of heat, cold and a radiant energy. Dignity. M.'s norms divide on optimum (a zone of thermal comfort) and admissible. The optimum rules are respected on objects with increased requirements of thermal comfort: in-tsakh, child care facilities, theaters, clubs, etc. There is a number of industries, in to-rykh not only on a gigabyte., but also on tekhnol, optimal conditions of M. are necessary for requirements (radio engineering, the electronic equipment, exact instrument making, etc.). Admissible norms of M. provide efficiency of the person at nek-rum tension of system of thermal control of an organism. Adhere to these norms when for a number of reasons the level of the modern equipment cannot provide optimum norms yet. Dignity. M.'s norms for objects of different function are usually developed for the cold and warm periods of year, and in some cases and on climatic zones, being based on separate determination of temperature, humidity and speed of the movement of air.

M. dwellings (see) and public buildings (see. Buildings public ) is defined by their appointment and the device in them heating (see), ventilation (see), air conditionings (see) etc. The dwelling allows people to live practically in any climatic zones of the globe. According to climate of the region and under the terms of heat exchange of rooms with the environment distinguish four types of dwellings: open, half-open, closed and isolated. The m of dwellings shall provide conditions for favorable recovery fiziol. shifts after work, i.e. conditions of thermal comfort shall be created. It presents considerable difficulties since people of a different sex, age and various professions live in dwellings. M.'s conditions in rooms in winter season generally decide by heating preferential on convection or radiant heat exchange, to-ry is defined by the device of heating devices and their placement. At the most widespread in dwellings and public buildings to convection system of heating t ° 18 ° for many years was considered as a zone of thermal comfort. However in many countries of the requirement to optimum air temperatures in rooms raised: so, in the USA they make 22,0 — 23,0 °, in England — 20,0 °, Japan — 21,8 °, Holland — 20,0 °, Finland — 21,0 — 22,0 °, Denmark — 20,0 °, Switzerland — 21,0 — 22,0 °, Germany — 21,0 °, France — 20,0 °, the USSR (moderate climatic area) — 20,0 — 22,0 °. It is established that the zone of thermal comfort lies within 21 — 23 ° at optimum t ° 22 °. Temperature of barriers and a floor, especially in the north is of great importance. The difference between surface temperature of internal walls and air about them shall not be more than 5 °. Temperature drop of air down shall not exceed 2 — 3 °, and across — 2 °. Relative humidity — within 30 — 60%. Speed of the movement of air is not higher than 0,15 m/s. Designs belong to radiant systems of heating, in to-rykh in panels pipes with the circulating heat carrier are put. At air temperature 15 — 20 ° temperature of the ceiling heating panels depending on height of the room is recommended 35 — 45 °, and at wall panels 30 — 34 °; at floor system of heating temperature of a floor depending on air temperature can be from 21 to 28 °. Great value, especially in the north, temperature of the glazed surfaces in rooms of different function has, edges it is recommended not lower than 12 °. Low temperature of barriers strengthens radiation cooling of an organism at the persons which are near them. In summertime of year, except special designs and devices on protection of buildings against an overheat, apply the air conditioning system and radiation cooling of rooms. Optimum parameters M. for summer at air conditioning are slightly higher, than in the winter, and make: air temperature 23 — 25 °, humidity of 30 — 50%, speed of the movement of air of 0,2 — 0,3 m/s. The radiation cooling system of rooms (ceiling and wall panels) is one of effective actions since it, especially in the conditions of hot climate, can be used also at open windows, and in the winter for heating.

Production M. is defined tekhnol, and differs in process and climate of the area in a big variety. It is schematically possible to allocate the most often found types M. inherent in certain groups of productions.

1. Production M. with optimal («comfortable») weather conditions, to-rye in some cases are created using air conditioning systems and radiation cooling (the cooling panels), napr, in electronic, radio engineering, textile and other types of the industry. Air conditioning system and radiation cooling finds more and more broad application in production rooms, especially in hot climatic zone.

2. The production M. which is characterized by preferential convection heat release: a) heat releases are the insignificant, not exceeding 20 kcal/m3-hour; a source of heat release are hl. obr. the people working in the workshop and cars; b) heat releases considerable (20 kcal/m3 - are higher hour); source of heat releases are the allocating warmly various cars and units (the heating microclimate).

3. The production M. which is characterized preferential by allocation of radiant heat (a radiation microclimate). Sources of radiation are heated metal, furnaces etc.

4. The production M. which is characterized by considerable moisture allocation: a) considerable moisture allocations at small heat releases or at low air temperature in the workshop; b) considerable moisture allocations at high temperature of air in the workshop.

5. The cooling M. in the presence of the low air temperature and barriers.

6. The microclimate on open working areas and territories, to-ry is defined by climate and weather of the area.

Microclimatic conditions in production activity of the person quite often are the basic: the factor defining working capacity and health working, and thereby and labor productivity. A number of the researches conducted by the Soviet and foreign specialists M. Tak establishes connection of labor productivity with conditions, spinners of textile plant at air temperature in the workshop 28 — 29 ° carry out operation on elimination of break of thread for 3 — 5 sec., and at air temperature 34 ° spend more for 1,1 sec., reducing labor productivity by 20 — 30%. In coal mines at rise in air temperature with 25 to 29 ° labor productivity decreases by 3 — 4% for each degree.

In hot workshops at air temperature St. 35 ° productivity, work decreases by 15%.

The m of various production rooms shall correspond a dignity. to norms (tab. 1, 2, 3), and also dignity. to rules, in to-rykh actions for normalization of working conditions are provided in certain industries.

Favorable M.'s creation in workshops and in workplaces is promoted by a rational structure of buildings, mechanization and automation tekhnol, process, aeration, ventilation and air conditioning, radiation heating and cooling of the corresponding surfaces, individual protection equipment, etc. In the winter protection working at the open territory is carried out by means of heat-protective clothes of of a rational work-rest schedule and heating of workers on special points. In summertime of year all actions are directed to protection working from overheating and solar radiation.

M. under clothes is important, to-ry it is formed as a result of heat exchange of the person with the environment. The air volume which is between a body and clothes at the adult makes apprx. 30 l. Temperature of this air depending on state of environment and heat-protective properties of clothes can fluctuate from 27 to 35 ° at relative humidity from 40 to 95%. In the conditions of thermal comfort at rest or works air temperature iod clothes 29 — 32 ° and relative humidity of 40 — 60% at almost still air.

During the definition a dignity. M.'s norms in modern conditions research of such optimal conditions is necessary, to-rye could establish compliance between climate of the area, on to-ry the device of thermal control of the population, and M. of production rooms and the dwelling is adjusted. In premises there is a recovery funkts, the shifts caused by M. of production and climate of the area. The dignity managed, i.e. regulated by means of special shall play a special role. - tekhn, installations, artificial M., to-ry will be widely carried out with development a dignity. technicians, in particular air conditionings, various cooling systems and heating of rooms. So, dynamic M.'s creation, e.g. for removal of exhaustion at monotonous work or for decrease in air temperature in sleeping rooms, etc.

== Tables == is possible at night in some cases Table 1. Optimum norms of temperature, relative humidity and speed of the movement of air in a working zone of production rooms (in constant workplaces) with insignificant excess of explicit heat (&20nbsp; kcal/m 3 - &chasnbsp; less) depending on category of work and the periods of year

Table 2. Admissible norms of temperature, relative humidity and speed of the movement of air in a working zone of production rooms (in constant workplaces)

Table 3. Norms of temperature and speed of the movement of air at an air dushirovaniye depending on the period of year, category of work and size of thermal radiation

Bibliography: Provincial Yu. D. and Korenevskaya E. I. Hygienic bases of conditioning of a microclimate of residential and public buildings, M., 1978, bibliogr.; To l of e of N about in and the p C. A microclimate of handling medium, in book: Ergonomics, under the editorship of V. F. Vend, the lane with polsk., page 198, M., 1971; Climate and the person, under the editorship of A. A. Gerburta-Geybovich, etc., M., 1972, bibliogr.; Malysheva A. E. Hygienic questions of radiation heat exchange of the person with the environment, M., 1963, bibliogr.; Fundamentals of bioastronautics and medicine under the editorship of O. G. Gazenko and M. Calvin’ t. 2, book 1, page 105, M., 1975; III and x and-zyan G. of X. ishleyfmanf. M. Gigiyena of a production microclimate, Kiev, 1977, bibliogr.; F anger P o’ Thermal comfort, N. Y. and. lake, 1970, bibliogr.

And. E. Malysheva.