Apeil 30, 1915] 



SCIENCE 



635 



recirculation of the air used for ventilation. 

 The New York State Commission on Venti- 

 lation, established through the generosity 

 of Mrs. Elizabeth Milbank Anderson, has 

 been actively interested in this work, and 

 worthily so, for should it prove practical 

 the cost of ventilating would be materially 

 reduced. At one of the first meetings of 

 the commission arrangements were made to 

 carry on research work in this field. It was 

 found that experiments along this line had 

 been conducted by Dr. J. H. McCurdy, at 

 the International T. M. C. A. College Gym- 

 nasium, at Springfield, Mass., and at the 

 Jackson School, Minneapolis, by Professor 

 Frederic Bass. With the direction and 

 support of the commission both of these 

 experiments were continued under im- 

 proved conditions. 



In the former case use was made of the 

 plant installed for ventilating the building, 

 which was readily adaptable to the purpose.^ 



This system included motor-driven supply 

 and exhaust fans, heaters and an air washer 

 of 36,000 to 40,000 cubic feet per minute 

 capacity, or over 300 cubic feet per minute 

 per occupant. It is such a system as is 

 usually used for ventilating such buildings, 

 and not an experimental plant, except that 

 the volume of air used was larger than 

 usual. By the manipulation of dampers 

 the air could be supplied entirely from out- 

 of-doors air, the air could all be recirculated 

 or part outdoor air and part recirculated 

 air could be used. The air could be washed 

 or not, as desired. Experiments were made 

 under all of these conditions, the subjects 

 being the college students at exercise in the 

 gymnasium, usually about 70 in number. 



The carbon dioxide content of the air, the 

 humidity and the temperature were care- 

 fully studied. Also studies of the efficiency 

 and results of air washing were very care- 



1 Described by G. P. AflBeek in Am. Phys. Educ. 

 Beview, April and June, 1912. 



fully made by Mr. M. C. Whipple, of Har- 

 vard University. 



The conclusion was reached that there 

 seemed to be no appreciable difference be- 

 tween washed recirculated air and outdoor 

 air similarly treated so far as bodily com- 

 fort is concerned. Naturally the propor- 

 tion of carbon dioxide is greater when using 

 the recirculated air, but no significance is 

 attached to this fact. Mr. Whipple con- 

 cludes "that recirculation provided a 

 plentiful supply of air with no apparent 

 sacrifice of wholesome properties, and that 

 it is a safer source of supply than outside 

 unwashed air." 



During the winter of 1913-14 further 

 studies were made at Springfield under the 

 direction of the Ventilation Commission, 

 the results obtained from recirculated air 

 being equally as satisfactory as those ob- 

 tained from the use of outdoor air. Win- 

 dow ventilation failed to give satisfaction. 



Odors were not noticeable to those 

 occupying the room during the use of re- 

 circulated and washed air, although some- 

 times barely notieeable to one entering 

 from out-of-doors. 



Conclusions were based upon the results 

 of physiological examinations and comfort 

 votes of the students. 



In the second case a special plant was 

 installed for one room of the school build- 

 ing, the pupils in the room serving as sub- 

 jects. The air was introduced into the room 

 at the top of each desk through a 2-ineh 

 vertical riser from a duct below the floor, 

 emerging through a funnel-shaped, nearly 

 horizontal orifice, at a velocity which was 

 barely perceptible at a distance of two feet 

 from the opening.^ Air was also introduced 

 at the top of the blackboards at the ends 

 of the room. The air was exhausted 

 through fifteen 3-inch openings evenly 



2 Described in paper read by Professor Bass be- 

 fore Am. See. H. and V. Engineers, July, 1913. 



