PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Tech Log (https://www.pprune.org/tech-log-15/)
-   -   Oxygen depletion in an unventilated airliner? (https://www.pprune.org/tech-log/483311-oxygen-depletion-unventilated-airliner.html)

ZeBedie 21st Apr 2012 18:18

Oxygen depletion in an unventilated airliner?
 
If the aircraft sits on stand for some time, with no air conditioning, doors closed and a full load of passengers, how much will the oxygen/CO2 ratio change? Is this a threat to people with breathing difficulties? Have any studies been done?

Checkboard 21st Apr 2012 18:41

Google is your friend:

Endless Forms Most Beautiful » Blog Archive » Friday Fiction Facts: Trapped in an airtight room!


T = Number of hours before CO2 reaches toxic levels and your character(s) could die.

(Volume of air inside the room in cu ft) x (3% or 0.03)

T = ---------------------------------------------------------

(Number of people) x (one person's hourly production of CO2 in cu ft)
For a full Airbus A319:

Cabin length: 23.78m, Diameter: 3.7m = rough volume: 256 m³ = 9 040 ft³
Number of people: 156 passengers + 4 cabin crew
Resting CO2 rate = 0.4 ft³/hour (0.19 L/min from this NASA study)

From Wiki: Carbon dioxide - Wikipedia, the free encyclopedia

Adaptation to increased levels of CO2 occurs in humans. Continuous inhalation of CO2 can be tolerated at three percent inspired concentrations for at least one month and four percent inspired concentrations for over a week. It was suggested that 2.0 percent inspired concentrations could be used for closed air spaces (e.g. a submarine) since the adaptation is physiological and reversible.
So, time to 3% CO2 limit = about four and a quarter hours. :8

Mind you, I think someone might open a door or turn on the aircon before then :rolleyes:

Swedish Steve 21st Apr 2012 22:12

And the lav/galley vent fans and the avionic ventilation system fans are all running and pumping used air overboard.

spannersatcx 22nd Apr 2012 08:19

Also aircraft are not airtight.:eek:

Checkboard 22nd Apr 2012 10:57

Not airtight by any means - but there wouldn't be enough air exchange to matter if the packs and fans were off.

Microburst2002 22nd Apr 2012 19:48

NASA knows well. They had this question with Apollo13


All times are GMT. The time now is 22:15.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.