- #1
CCWilson
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What are the calculations to figure out how long someone can live in a sealed room of a certain volume? Please check mine.
Let's say that the room is 30 feet by 20 feet by 8 feet, or 4800 cubic feet.
I believe that high carbon dioxide levels will kill you before low oxygen levels will. Inhaled carbon dioxide is 0.04% by volume, exhaled is a bit over 4%. Inhaled oxygen is 21%, exhaled 15%, a difference of 6%.
A person breathes about 6 liters per minute, or roughly 9000 liters/day or roughly 300 cubic feet/day. Thus that person will decrease room oxygen by 300 x 6% = 18 cubic feet/day.
He will increase room carbon dioxide by 300 x 4% = 12 cubic feet/day.
Comfortable carbon dioxide levels are less than 1000 ppm (parts per million) (0.1% of room air).
Dangerous levels are above 10,000 ppm, especially above 30,000 ppm. Let's take 30,000 ppm (3% of room air) as our death point, although obviously that's arbitrary.
0.03 times 4800 = 144 cubic feet of carbon dioxide in the room would be deadly.
144 / 12 (cubic feet of CO2 exhaled per day) = 12 days to death in that sealed room.
Originally there were 4800 (room cu ft) * 0.21 = 1000 cu ft of oxygen (rounded)
After 12 days, 18 (cu ft/day of oxygen decrease) x 12 = 216 cubic feet oxygen lost.
That leaves 784 cubic feet of oxygen in the room, or 784/4800 = a little over 16% oxygen in the air. While people will have symptoms at 15% or less, it would be rare to die with oxygen levels above 10%.
So my conclusion is that in the above scenario, a person would die in around 12 days, and from carbon dioxide toxicity rather than oxygen deprivation. Are my calculations correct on this? Thanks.
Let's say that the room is 30 feet by 20 feet by 8 feet, or 4800 cubic feet.
I believe that high carbon dioxide levels will kill you before low oxygen levels will. Inhaled carbon dioxide is 0.04% by volume, exhaled is a bit over 4%. Inhaled oxygen is 21%, exhaled 15%, a difference of 6%.
A person breathes about 6 liters per minute, or roughly 9000 liters/day or roughly 300 cubic feet/day. Thus that person will decrease room oxygen by 300 x 6% = 18 cubic feet/day.
He will increase room carbon dioxide by 300 x 4% = 12 cubic feet/day.
Comfortable carbon dioxide levels are less than 1000 ppm (parts per million) (0.1% of room air).
Dangerous levels are above 10,000 ppm, especially above 30,000 ppm. Let's take 30,000 ppm (3% of room air) as our death point, although obviously that's arbitrary.
0.03 times 4800 = 144 cubic feet of carbon dioxide in the room would be deadly.
144 / 12 (cubic feet of CO2 exhaled per day) = 12 days to death in that sealed room.
Originally there were 4800 (room cu ft) * 0.21 = 1000 cu ft of oxygen (rounded)
After 12 days, 18 (cu ft/day of oxygen decrease) x 12 = 216 cubic feet oxygen lost.
That leaves 784 cubic feet of oxygen in the room, or 784/4800 = a little over 16% oxygen in the air. While people will have symptoms at 15% or less, it would be rare to die with oxygen levels above 10%.
So my conclusion is that in the above scenario, a person would die in around 12 days, and from carbon dioxide toxicity rather than oxygen deprivation. Are my calculations correct on this? Thanks.