Report of the Coloured Labour Compound Commission appointed to enquire into the cubic amount of air-space in the compounds of the mines of the Witwatersrand.

Date:
1905
Catalogue details

Licence: In copyright

Credit: Report of the Coloured Labour Compound Commission appointed to enquire into the cubic amount of air-space in the compounds of the mines of the Witwatersrand. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    Appendix H. APPENDIX H. CALCULATION OF AIR-CHANGE. The following letter was received from Mr. J. R. Williams :— [Copy.] Metallurgical Department, H. Eckstein & Co. Dr. James Moir, Secretar}^, Air-Space Commission, Johannesburg. Dear Sir, I beg to send you, enclosed herewith, twelve copies of certain calculations which have been made, for the use of members of the Commission. Yours faithfully, John R. Williams. J ohannesburg, Transvaal, 14th October, 1904. [Enclosure.] Results as per Experiment for 35 Boys in Room of 8,700 c.f. of Air-Space. At I a.m.— Average internal air .. .. 0-003685 c.f. CO2 per* c.f. air. Average outside air .. .. 0-000363 do. do. Vitiation of air, difference 0-000322 do. do. in room. Room contains 8700 c.f. air. Total vitiation of air in room 8700 X 0-000322 35 boys at 0-6 c.f. per boy per hour for 2 hours 35 X 0-6 X 2 If air were not changed vitiation would now be = 2-8014 c.f. CO2. = 42-0000 do. .. 44-8014 do. At 3 a.m.— Actual condition is ;— Internal air .. .• •• •• •• 0-000640 Average external air .. .. .. .. o - 000363 Vitiation .. .. <• •• -- -- 0-000277 8700 X 0-000277 = 2-4099 c.f. CO2. Amount of CO2 vented from room in 2 hours .. Amount of CO2 vented from room in i hour Avera<^e vitiated air above outside air at i a.m. .. '’do. do. do. 3 a.m. .. 42-3915 c.f. 21-19575 c.f. 0-000322 CO2 per c.f. 0-000277 do. Average .. .. • • .. 0 0002995 Each c.f. of air vented per hour, therefore, carries away ; 0-0002995 c.f. of CO2 .-. c.f. of air which must circulate per hour. 21-19575 70770'45 0-0002995 8700 capacity of room Air changed 8.1345 times = 2022 c.f. of air circulated per boy per hour.