732 



YKNT1I.ATION. 



ventilation. and in sonic instances tlioy arc combined, I location of the building itself may influence the luat- 



hot (nr cold) pure air In-ing forced in and liiul air ing and ventilating "I its rooms, while the lijJit em- 



extracted at the same time. Scientifically considered, ployed (Candle, gas, or electric) must also n-<t-ive 



one WniiM tliink that the great clasliciiy of the air attention, .MI that no sy.-ti-in i-an U- said In ! \-t-i 



would be on objection to propulsion for the reason however satisfactory ii may be under favm 



that a ruoui could be surcharged with air without m-.- dilioiig. 



eswily changing it as rapidly as, it entered; while The <//* fire, which mo.-t closely i the 



on the other hand, hy u.-piration, it would chaiii:c at sun's heat by direct radiation (and is doubtless the 



the same rate as it was extracted, on the principle that niu.-t. heallhlii!). may answer tor warming and \ci.ii- 



"ntilure abhors a vacuum.'' Theories in ventilation lating small rooms, the demands liir combustion prc- 



and wuruiing are as numerous as trees in a Ion M. and 

 it i> only by practical tests and cx|>eriuieiitti that the 

 question ran be settled. 



The question of "up-draP. " or "down-draft" is 

 equally discussed by cnginors and sanitarians, and 

 opinion is divided as to which of the two systems is 

 the best. In the first, the extraction of foul air is 

 made from the top of the room, and in the other 

 from the bottom of the room. The former is the 

 system that has been employed in the Halls of Con 

 lor over a quarter of a century, while the latter 



venting the air from becoming stagnant ami killing 

 it in constant motion towards the fire-place ; but this 

 very movement of air creates a scn.-ation of dis- 

 comfort, as a draught from the colder portions of the 

 room or from the cracks and crevices around the 

 doors and windows chills the feet and hacks of those 

 sittiiiL' in front of the fire, for it must be remembered 

 that the air itself is not warmed by the tire'. ]!y sup- 

 plementing the open fire with wanned air from other 

 sources (small furnaces, etc. V or admitting tie 

 air back of the tire-place, where it is warmed and de- 

 livered into the room (radiating prates), the dis- 

 comfort spoken of may be in great measure obviated. 

 The slurr is probably the most economical and most 

 generally used means lor warming small dwellings and, 

 when properly made, nd set with a view to ventila- 

 tion, is, next to the fire-place, the most healthful. 

 There are thousands of different pattern* of si 

 from the "thermometer stove" of Dr. Arnott. in- 

 vented in 1SSS. and the original " Franklin sto\. 



is coming into more general use in public buildings in 

 recent years. 



The change of air necessary to constitute perfect 

 ventilation and warming depends upon the sire of the 

 room and number of its occupants. As has already 

 been stated, each individual should be supplied with 

 fresh air at the rate of one cubic foot per second, and 

 to prevent the unpleasant sensation of a draught the 

 movement of air should not exceed .'! feet per second ; 

 In'tter if but 1 or H l>er second. It will be observed 

 that the inlets and exits to the room must bear a ccr 

 tain proportion to its -i/e and the velocity of the air's 

 movements; it then becomes a mere matter of mathe- 

 matics to determine the question of how much air is 

 needed and how frequently it must lie changed. 

 Parke says "it may be fairly assumed that the quan- 

 tity of air supplied to every inhabited room should be 

 great enough to remove all sensible impurity, so that 

 a person coming in from the external air should per 

 ceive no trace of odor or difference U'tween the room 

 and the outside air in point of freshness. Taking the 

 carbonic acid as the index of impurity it appears 

 f.-om experiments made by Dr. DcChaumont and 

 myself that the organic impurity of the air is not 

 perceptible to the senses until the carbonic acid (i. /., 

 the initial and respiratory carbonic acid) rises to the 

 ratio of .o per KKXI volumes, or .(Win; to each cubic fool. 

 Occasionally air may s< em pure to the senses when 

 the carbonic acid is .7 or e\en .s per KKH) volumes. 

 but the usual rule SCCI1IS to be when it exceeds ,<i the 

 air commence- to brcoine perceptibly impure. When 

 the carbonic acid reaches .'.I or I JMT KXH) vwluim-s. 

 the air is what is called close and fusty; above this it 

 becomes disagreeable." 



Mow to warm as well as ventilate a room is a ques- 

 tion of importance to a large section of our diversified 

 country. Healing without ventilation is no longer 

 deemed prudent, and the best means to accomplish 

 this double purpose is one that is still tali Jmlirt. 

 The fire-place or grate, the stove of many patterns, the 

 furnaces without number, the steam-pipes or coils. 



hot-water pipes, radiators, and what not. arc to be _ r _ ,._ 



found everywhere, while the manner of introducing ventilating shaft. The disagreeable noi.-i s n suiting 



hi aled air into large r us and public buildings, even from turning tin 1 steam into partially healed or cold 



after the kind of apparatus for heating them has coils is said to be DOW obviated by the use of but one 



ii fixed upon, is no easy question to decide. Shall (<( of pipes, the condensed steam (water) returning 



tin 1 heat lie admitted at the floor and the foul air alongside the steam from the boiler: of course this also 



racted at the ceiling, or r/V. r.r.i? shall it lie docs away with the extra valve and drip-cock at the 



forced in (plenum), or shall it be drawn in (vac distal ena of the set of oofls. 



mini)? if propulsion is used, a fan -wheel is necessary ; fiesta? Otr supplied by either furnaces, steam coils, 

 if suction is preferred, a heated ventilating shaft, or a or hot water pipes located in the basemiiit. is a \cry 



fan wheel (|H'rhaps both), will In 1 r< quired: while a common plan for heating fnshi ible dwellings, large 



combination of plenum and vacuum will certainly buildings, churches, school houses, theatres, etc., the 

 ile fan-wl,. .eh. Then the condition healed air being conveyed through duels buil; for I hat 



of the outside air has to lie considered, whether cold pur|>ose. and delivered where wanted. The general 

 or warm, moist or dry, high wind or moderate, and plan of such furnaces, coils, and pipes may be briefly 

 the point of the compass from which it cornea ; the , stated as follows : The object being to obtain as large 



earlier date, to the styles of the present day. What- 

 ever pattern is used the following points must be con- 

 sidered : The Stove should have a large healing sur- 

 face, and IK' encased, except at the top. to | i 

 direct radiation the object being to heat the air com- 

 ing into the room and not the persons immediately 

 around it. A fresh air duct from the external atmos- 

 phere delivering the pure air inside the i 

 surrounding the MOW will give an equal tempentora 

 throughout the room, while the under draft to the 

 stove will ordinarily remove the foul air by suction. 

 thoUL'h il is better to I ave an opcniiii: <m a h \el with 

 the floor, connecting with a heated ventilating shaft. 

 An urn or other vessel filled with water should be kept 

 on top of the stove. When the gas is lighted or the 

 ro< m IM-COIIICS too warm another opening (fitted with 

 a rcu'i-ter) near the ceiling nnil connecting with the 

 heated shaft may be o| died occasionally. It must be 

 remembered that the temperature of a room is trj 

 index to the purity of the air. 



Sli'nin lii'iifi'iit/ is now largely used in public build- 

 ings, hotels, offices, and in not a few private r< ridl 

 and if proper ventilation and indirect radiation i.- com- 

 bined with it. DO serious objection can l>c m 



it. or against Imt initi-r Itmtiuif (meaning there by the 

 heat radiated by pipes or coils in llic rooms ami 

 halls of buildings, and not healing from Mich pipes 

 placed in basements and coiidin led through flues to the 

 rooms aliovc). In such case.- fre.-h air from ihc out- 

 side may be delivered among the coils, thus securing 

 indirect with direct radiation, or admitted at the top 

 of the room, care being taken that liml air duels from 

 openings level with the floor be connected with a warm 



