Читать книгу Mechanics of the Household - E. S. Keene - Страница 42

—It is customary to place the conducting pipes for the first floor in such a way as to use only the shortest connections. The flues used for the second floor produce, as in a chimney, a greater velocity of flow to the air and as a consequence larger horizontal pipes are used at the furnace. All horizontal pipes should have upward slant, as much as the basement will permit.

The velocity of the air in the conducting flues will depend on two factors: the height of the flue, and the temperature of the air. To prevent the loss of the temperature of the air, the flue should be covered with at least two layers of asbestus paper bound with wire. Wall flues are commonly flattened and occupy a place in the wall between the studding. Each flue should have a damper at the furnace, that will permit the heat to be shut off from any part of the house.

Rules for proportioning of registers and conducting flues to suit rooms of various sizes are entirely empirical. The sizes of registers and flues found satisfactory in practice is generally a guide for the designer. The following table is taken from a manufacturer’s catalogue and gives a list of sizes that have proven satisfactory under a great variety of conditions and may be taken as good practice:

First Floor
Sizes of registers in inches	Diameter of pipes in inches	Size of rooms in feet	Height of ceilings in feet
12 by 15	12	18 by 20	11
10 by 14	10	15 by 15	10
9 by 12	9	14 by 15	9
8 by 12	9	13 by 13	9
Second Floor
10 by 14	10	18 by 20	10
9 by 12	9	16 by 16	9
8 by 12	8	13 by 13	8
8 by 10	7	12 by 12	8

The furnace is not only a means of heating the house but may be a means of ventilation as well; to this end it is desirable to arrange the air supply of the furnace to connect with the outside air. This arrangement assures a supply of oxygen even though no special means is arranged for discharging the vitiated air from the rooms.

Fig. 47.—Interior construction of a combination hot-water and hot-air furnace.