R. C. Carpenter

“ It a way, odors might be treated as pertaining to the same class of deleterious substances as dust, but they have a property not possessed by ordinary dust of affecting the organs of smell.
Odors vary greatly in character and have great effect upon the nervous organism of the human body. Many odors are, extremely pleasant, and some have an exhilarating effect, while other odors are extremely unpleasant and have exactly the reverse effect. Unfortunately, all people are not agreed as to the character of odors. Gases that smell pleasant to some people are extremely unpleasant to others. ”

“ The ventilating engineer is under the serious handicap of not having a definite standard to work by which would enable one to judge of the perfection of his work. His work is naturally of a varied character. First, he must introduce the proper quantity of air to supply the necessary amount required for the best sanitary conditions; second, he must purify that air so as to remove from it objectionable dust, smoke or odors and regulate its humidity; third, he must introduce this air at the desired temperature ”

“ Briefly, these experiments have indicated that the human subjects suffered very little or none at all by deduction in the amount of oxygen supplied to from 21 to 16 per cent, and an increase in the carbon dioxide content to nearly 5 per cent., provided the air in the enclosure in which the body is situated is kept in motion, the temperature maintained at less than 74 degrees and the percentage of humidity kept from reaching an excessive amount. If the air is not kept in motion, or if there is excessive moisture or high temperature, suffering is soon evident from the lack of ventilation. ”

“ As is well known, smoke is a product of combustion which would not occur, at least to any sensible amount, if the combustion were perfect. It is, therefore, of itself an evidence of economic waste. While I shall not have time to make any discussion whatever of the smoke problem, I would state that it is very largely preventable by the installation of proper appliances and proper methods of operation of plants which produce it. ”

“ The ventilating engineer in his work has been greatly handicapped in the past by the lack of a definite standard acceptable to all as to what constitutes good ventilation. It is the engineer's business to design machinery and processes for producing definite results rather than to decide just what character the results must have in order to produce satisfaction. ”

“ Since the year 1880 it has been known to play an important part, and instead of being a nuisance it adds much to the comforts and pleasures of life. Every cloud particle owes its origin to a growth around a nucleus of dust. As a consequence, without particles of dust clouds would be impossible. The presence of dust in the atmosphere allows the condensation of the vapor to take place whenever the air is cooled to the saturation point. If there were no dust present, condensation would not take place until the air was cooled far below that point. ”

“ As an illustration, the odor of cooking may be pleasant to some, whereas to others it may be extremely unpleasant. Odors are not necessarily harmful, and generally speaking they do good rather than harm. Odors are produced by a great variety of substances, and, as stated above, vary in quality from the most disagreeable nature, which is almost sufficient to cause sickness, to the most pleasant and delightful nature such as characterize our most expensive perfumes. A great majority of the disagreeable odors in chemical composition are complicated compounds of carbon and hydrogen. ”

“ The odorous gases, with scarce an exception, are combustible and are converted by the process of combustion into carbon dioxide, water and other non-odorous materials. Certain odorous gases like ammonia are absorbed in large quantities by water, and although by that process the odor is not removed, the air is however very greatly purified. ”

“ The air is frequently charged with smoke particles. In a general way, smoke particles are to be considered as a peculiar character of dust. They are peculiarly disagreeable because the particles are generally black in color and consequently render everything on which they settle of a disagreeable black and sooty color. The disagreeable part of smoke from the ventilation standpoint consists of the small particles of carbon which float in the air. ”

“ Air in order to be comfortable should contain some moisture. Out-of-doors air is, under usual conditions, from 30 to 70 per cent. saturated and such a degree of saturation is, in accordance with investigations, more sanitary than either extremely dry or extremely damp air. When air is saturated with moisture, water is deposited on all bodies which conduct heat readily and have a lower temperature than the air. ”

“ Time will not permit any further discussion of air conditioning processes, but enough has been said to indicate that the subject is of itself an extensive one and could profitably be made the entire subject of an evening's meeting. ”

“ Without doubt, it is true that so far as quality is concerned our best standard is the external air surrounding the building to be ventilated. Investigation also indicates that the utilization of the external air for natural ventilation by raising the windows and regularly admitting the air to the apartment to be ventilated is desirable when the conditions are favorable. Generally speaking, it is not desirable to have a system bf ventilation which will not permit the direct communication with the outside air by the opening of windows. ”

“ The washing of the dust particles from the air frequently charges the air with an excess of moisture so that the apparatus for air conditioning must be provided with means for separating or taking out excessive water if necessary. ”

“ Air conditioning usually requires the control of the temperature of the air, and this in turn requires heating coils which are under thermostatic control so as to bring the air passing through to the desired temperature. ”

“ Respiration is a common source of impurities. The air in inhabited rooms is contaminated principally from the products of respiration of the people in the room. The contamination of air by the products of respiration requires the closest investigation on the part of the ventilating engineer. ”

“ It however must be recognized that no supply of a definite amount can be obtained by merely connecting a room with the outside air by opening a window, and that as a consequence a system of ventilation which depends alone on the opening of windows will be certain to fail and will be certain to give air which will differ largely from the external air surrounding the building. ”

“ Formerly it was customary to remove dust particles by passing air through cloth filters which were kept continually wet, and such filtering processes may still be found in operation. But I believe that new filtering plants are at the present time not being installed to any great extent, while the spray washing systems are being installed to a great extent.
Air always contains water vapor. The maximum weight of water vapor which can be absorbed by the air is a function of the temperature. ”

“ Various experiments have been made on human subjects enclosed in hermetically sealed boxes provided with windows, which experiments have tended to check or verify the conclusions drawn from the physiological investigations to which I have already referred. ”

“ It is, however, certain that they cause an immense economic loss by discoloring buildings and by soiling clothing, house furnishings and everything that pertains to life. Smoke particles are frequently of considerable size and are retained in the nostrils to a considerable extent during the processes of respiration. ”