106 VETERINARY HYGIENE 



It is difficult to set an arbitrary standard for ventilation, because 

 what might be adequate in an exposed position would be notably 

 deficient for some city byres that are closely surrounded by other 

 buildings. 



It is clear that the cubic air-space per animal must be 

 sufficient to allow of satisfactory ventilation without the premises 

 being too draughty. The cubic space must not be made up by 

 giving an inordinate height to the building, that is to say the floor 

 space must be sufficient. Local authorities are recommended by 

 the Local Government Board that, in calculating air-space, no space 

 shall be reckoned which is more than 16 feet above the floor; but if 

 the roof or ceiling is inclined, then the mean height of the same 

 above the floor may be taken as the height. 



The question really depends upon the nature of the roof as has 

 been already discussed, but a good working method is to construct 

 the building so that the number of superficial feet in the floor is not 

 less than one- fourteenth to one-fifteenth of the number of total 

 cubic feet in the building. Thus in the byre dimensions suggested 

 on page 172, the floor area is 65 square feet per animal, or one- 

 fifteenth of the total number of cubic feet, and, in the case of the 

 stable for heavy horses (page 148), the floor area is 136 square feet 

 per head, or one- fourteenth of the total number of cubic feet. The 

 net cubic space per animal must be calculated by making deductions 

 for the space occupied by the animals, approximately 18 to 20 

 cubic feet per horse or cow, and by supporting pillars, if any, or 

 other fittings that appreciably reduce the available air-space. 



The position, nature, and capacity of all inlets and outlets must 

 be noted, and it is important that all calculations be made for the 

 total number of animals that the building is capable of holding, 

 not for the number present at the time of the inspection. The 

 position and proximity of other buildings must be carefully observed, 

 as these may seriously reduce the ventilating capacity of both inlets 

 and outlets. 



If the inlets are placed too high in the walls they will not be 

 so efficient as at a lower level, as air entering at a high level would 

 tend to cause the hot and foul air to fall which is not desirable 

 unless the King system of ventilation is in use. 



A ventilating system should always be tested when the building 

 has been in full occupation for some hours and, as far as possible, 

 under average weather conditions. On first entering a building an 

 ordinary observer, who does not spend the greater part of his work- 

 ing day in a badly ventilated animal building, will at once notice 

 a difference in the smell and physical character of the air inside the 



