Carbon Dioxide Concentration in a Room with People

Carbon dioxide concentration in a room can indicate air quality and ventilation system efficiency

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

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)

CO2 Concentration Calculator

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

V - volume of the room (m3)

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

t - time (hour, h)

ci - carbon dioxide concentration in the make up air*) (m3/m3)

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

*) 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)

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.

Related Topics

• Physiology - Human physiology, air quality and comfort temperatures, activity and metabolic rates, health effects of carbon monoxide and more
• Fluid Mechanics - The study of fluids - liquids and gases. Involves velocity, pressure, density and temperature as functions of space and time
• Ventilation - Systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more

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