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if 20 <VN <40 m , it should be not less than 20 m /h of air.
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In areas with a volume of the room more than 40 m per 1 employee, and in the
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presence of natural ventilation (open windows and doors) air is not calculated.
In those cases, where there is no natural ventilation, the volumetric flow rate
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the per 1 employee should be not less than 60 m /h.

2) Assimilating (dissolution, dilution) harmful emissions to the maximum
permissible concentration
G
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L  , (m / h).
С  С makeup
ex
where G - the number of emissions per unit of time, which appear in the premises,
mg /h;
Cex, Smakeup - concentration of pollutants in the exhausted air and in the makeup
air.
With the simultaneous emissions in the working area air space several kinds of
pollutants, which have different influences on human health, needed volumetric

flow rate is equal to biggest volumetric flow rate of air from all volumetric flow rates,
which calculated for each harmful substance).

If there is a simultaneous emission in the working area air space several kinds
of the pollutants, which have identical influence on the human health, calculation
of summary volumetric flow rate performed by addition volumetric flow rates
required for assimilated (dilution) of each substance (1,2 ... n) to such concentrations
C1, C2, ..., that the condition:

С 1 С 2 С n 1
MPC 1  MPC 2  MPC n  ,

MPC - maximum permissible concentration.

3) The calculation volumetric flow rate of air , when there is the excess heat

6 , 3  Q
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L  , (m / h)
C   (t  t makeup )
ex
where Q - excessive heat, W (J / s).
The value of excess heat is determined by the formula:
Q   Q 1   Q 2 ,
where  Q 1 ¬- the total amount of heat entering the building (process, heat people,
etc.);
 Q 2 - the total amount of heat removed from the room (due to heat loss
through windows, doors, walls, etc.);
C - specific heat capacity of air kJ / kg ° C (1.0056 kJ/kg °C);
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ρ - density of air entering the premise, kg/m ;
tex – the temperature of the air, that removed (exhausted), °C;
tmakeup - the temperature of the incoming (makeup) air, °C.

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