A room has been occupied for one hour, at the end of which the total carbonic acid present was found to be 1·1 per 1,000 parts. The carbonic acid in the open air amounting to ·0004 per cubic foot, find the quantity of air supplied per hour.
- Here x = ·0011.
- p = ·0004 and P = ·6.
- Hence ·0011 = ·0004 + ·6 ∕ A.
- Therefore A = 857 cubic feet.
If six persons are in a room containing 3,000 cubic feet, and there is a supply of 2,000 cubic feet of air per head per hour; how much carbonic acid is there in the air of the room at the end of 4 hours?
- Here p = ·0004.
- P = ·6 × 6 × 4 = 14·4.
- A = 2,000 × 6 × 4 + 3,000 = 51,000.
- x = ·004 + 14·4 ∕ 51,000 = ·000682 = 6·82 parts CO₂ in 10,000 of air.
The air of a room occupied by 6 persons and containing 5,000 cubic feet of space, yields 7·5 parts of CO₂ per 10,000 parts of air. How much air is being supplied per hour?
A = P ∕ (x - p) = ·6 x 6/(·00075 - ·0004) = 10,280 cubic feet.
In the same room what would be the condition of the air at the end of 4 hours?
x = ·0001 + ·6 × 6 × 4/(10280 × 4 + 5,000)
= ·0004 + 14·4 ∕ 46,120 = ·000712 = 7·12 of CO₂ in 10,000 of air.
Given two sleeping rooms, Y 10 ft. by 15 ft. and 10 ft. high, Z 15 ft. by 20 ft. and 12 ft. high, with three adults in each; how much fresh air would you supply in each? What would be the condition of the air of each of the rooms after, ¼;, ½, 1, and 2 hours respectively?
Amount of fresh air to be supplied in Y—
A = P ∕ (x - p) = ·6 × 3/(·0005 - ·0004) = 9,000 cubic feet per hour.