Carbon Dioxide Concentration in Rooms Occupied with People (original) (raw)

The carbon dioxide concentration in a room can be used to indicate air quality.

Carbon dioxide - people and concentration in rooms

The Carbon dioxide concentration in a room filled with persons after a time - t - can be calculated as

c = (q / (n V)) (1 - (1 / en t)) + (c0 - ci) (1 / en t) + ci (1)

where

c= carbon dioxide concentration in the room (m3/m3)

q= carbon dioxide supplied to the room (m3/h)

V= volume of the room (m3)

e= the constant 2.718.....

n= number of air shifts per hour (1/h)

t= time (hour, h)

ci= carbon dioxide concentration in the inlet ventilation air (m3/m3)

c0= carbon dioxide concentration in the room at start,t=0(m3/m3)

Note that this equation can be used to calculate the concentration of any pollution as long as the pollution substance is homogeneous mixed with the air.

CO2 Concentration Calculator

*) normal carbon dioxide concentration in outside air is aprox. 400 ppm (0.0004 m3/m3).

Example - Carbon Dioxide Concentration in a Cinema

With an approximately carbon dioxide emission per person in a cinema of 0.05 m3/h - the CO2 emission from 100 persons can be calculated to approximately 5 m3/h.

If the carbon dioxide concentration when people enters the room - and in the inlet air - is close to zero, the CO2 pollution concentration in a 500 m3 cinema after one hour and with one air shift per hour, can be calculated as:

c =((5 m3/h) / (1 h-1) (500 m3)) (1 - (1 / e((1 1/h) (1 h))) + ((0 m3/m3) - (0.0004 m3/m3)) (1 / e(1 1/h)(1 h)) + (0.0004 m3/m3)

= 0.0067 m3/m3 (6700 ppm)

Carbon dioxide concentration in cinema or theatre with people

Note! - that with 6700 ppm(0.0067 m3/m3) of CO2 in the air - adverse health effects may be expected. One air shift per hour as used in this example is not enough.

Carbon Dioxide - Liquid Properties

Properties of saturated liquid Carbon Dioxide - CO2 - density, specific heat, kinematic viscosity, thermal conductivity and Prandtl number.

Human Need of Air

Fresh air is required for respiration and for transport of heat and vapor emitted from the human body.

Pollution Concentration in Rooms

Concentration of a pollution in a limited space as a room depends on the amount of polluted material spread in the room, supply of fresh air, outlets positions and construction, principles used for supply and outlet from the space.