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2729203 
Technical Report 
Ventilation Requirements 
Yaglou, CP; Riley, EC; Coggins, DI 
1936 
NIOSH/00060332 
Pharm 
REF 10 
137-139 
The outdoor air requirements for ventilation under comfortable conditions of temperature and humidity have been determined from primary impressions of odor intensity upon entering occupied rooms and from impressions of the occupants themselves after exposures of 3 1/2 hours to the conditions investigated. Wide individual variation occurred in the amount of odor emitted by various groups of persons, according to socio-economic status, especially the bathing habits of individuals and cleanliness of clothing. Children, as a rule, gave off more odor than adults, and their bathing habits were deficient. Even healthy clean persons freshly after a bath gave off an appreciable amount of odor which required from 15 to 18cfm of outdoor air per person in order to dilute it to a concentration that was not objectionable to persons entering the room from relatively clean air. A week after a bath the ventilation requirement of children increased from 18 to 29cfm, as compared with an increase of from 15 to 20 in the case of adults. With a given group of occupants the intensity of body odor perceived upon entering a room from relatively clear air (air with threshold odor intensity) varied inversely with the logarithm of the quantity of outdoor air supplied and the logarithm of the air space allowed per person. Untreated recirculated air in any amount had no effect on odor intensity or quality of air. The usual processes of washing, humidifying, cooling, and dehumidifying recirculated air apparently removed a considerable amount of body odor and, under certain conditions, practically the maximum amount possible by the use of known processes. Under comfortable conditions of temperature and humidity, both primary and secondary impressions of air quality were found to be related closely to the concentration of odor in the air, despite the fact that the occupants themselves could not smell the odor. Based upon these impressions, two sets of ventilation requirements were derived for various groups of individuals under various conditions: requirements based on primary impressions, and those based on the impression of occupants. The impossibility of fixing any single standard that would apply under all conditions is clearly evident. Each case, it would seem, must be considered on its own merits. The concentration of carbon-dioxide (124389) in the air of occupied rooms proved to be an unreliable index of ventilation, from the standpoint of both outdoor air supply and odor intensity. Discussions with Mr. Yaglou's replies are included following the article.