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Openings to the Ventilator 



The outtake flue should be properly coupled to the ventilator and reach 

 within one foot of the stable floor, so that air may come up the shaft from that 

 level. This is very important, in order that the coldest air at the floor be 

 removed during the winter, rather than the warm air at the ceiling. The 

 bottom opening should be made as large as the least cross section of the outtake 

 flue. An opening of the same size should be provided at the ceiling, however, 

 that moist air may be removed when conditions so require. 



This opening at the ceiling also provides for the escape of warm air when 

 the stable is too warm, and when it is desired to force the ventilation at the 

 expense of the heat developed by the animals. Both these openings should 

 be provided with regulating valves, so that either or both may be partly or 

 completely closed. 



Entrance for Fresh Air 



It will be noted from the different cuts shown, that in all cases the fresh air 

 enters at the ceiling. This is for the purpose of mixing it with the warmest 

 air of the stable, so as to raise its temperature before it falls to the floor. In 

 this way the heat which is rising to and is resting under the ceiling is saved. 

 The entering fresh air forces the foul air down and absorbs the excess moisture, 

 whence it can be carried off by the outlet flue. 



Provision is further made for the air to enter the intake outside midway 

 between floor and ceiling, so as to prevent the warm air being drawn out at 

 these places by suction, or to pass out directly as it would if they opened directly 

 through the walls. 



Construction of Flues 



A good form of ventilating flue is made of two layers of number one 

 matched stuff, %-inch thick, with building paper or deadening felt between, to 

 make it as nearly as possible a perfect non-conductor, thus preventing rapid 

 cooling of the air in the flue. This form of construction also makes the flue air- 

 tight, which is essential, for every hole and crack lessens the ventilating power. 



These openings should be placed on both sides of the stable, if possible, 

 in order to take advantage of the wind pressure that increases the draft. It is 

 better to have many small openings than a few large ones, because the cold air 

 is better distributed, lessening drafts. All intake flues should be equipped with 

 registers, so the air is at all times in control of the party in charge. Intake 

 flues may be made of galvanized sheets or wood. 



Intake flues should be insulated with a dead air space of one inch, as shown 

 in illustrations A and B on page 62. Unless so insulated, the cold air flowing 

 through the intake flue will condense the moisture of the warmer air of the 

 barn, and the wall and ceiling along the intake flue will be covered with 

 moisture or frost. 



