Army manual of hygiene and sanitation, 1934 / [War Office].

Date:
1941
Catalogue details

Licence: Public Domain Mark

Credit: Army manual of hygiene and sanitation, 1934 / [War Office]. Source: Wellcome Collection.

    64/310 (page 66)
    the shape of the room and the position of doors and windows demand it. These measures necessitate good barrack room discipline and constant supervision on the part of officers and non-commissioned officers of the unit, who should ensure that such measures receive precedence over any desire to achieve smartness by regular dressing of beds under equip- ment shelves. Ventilation.—Good ventilation means the provision of gently moving fresh air at a suitable temperature and humidity ; it also implies the provision of a sufficient amount of cubic space and fresh air therein to ensure that the occupants of the room do not suffer from the effects of impurities in the air, such as gases and germs. The composition of air and the effects of breathing into the air have been explained in Chapter II and it is therefore only necessary to repeat that the feeling of stuffiness and dis- - comfort in a badly ventilated room is due to the stagnation of the air, together with a rise of temperature and humidity result- ing from respiration. A healthy comfortable atmosphere in a room depends on (a) a temperature of about 60° F. (o) a relative humidity not exceeding 75 per cent. (c) a continuous gentle movement of the air at about three feet a second. It is calculated that each person in a room requires 1,000 cubic feet of fresh air every hour, but, if the air is replaced oftener than three times an hour by incoming air more than 5° cooler than the air of the room, a feeling of draught results. A cubic capacity of 600 cubic feet for each person with the air changed twice an hour will give a little over the necessary 1,000 cubic feet of fresh air without a feeling of draught. Ventilation may be either natural or artificial, but usually a combination of both is employed, especially for large rooms and theatres, and on board ship. Natural ventilation is normally employed in barracks and is obtained by diffusion, wind movement and movement of the air by inequality of temperature, the air being replaced through doors, windows or specially made openings. Diffusion takes place through bricks and other building materials, most of which are slightly porous, but it is too slow to be of practical importance. . Wind movement acts by perflation and aspiration. In perflation the wind blows into rooms through windows, or other openings, and to get the best effect rooms should be cross-ventilated, that is to say, there should be windows, or other openings, on opposite sides of the room so that the