This section is from the book "A Treatise On Architecture And Building Construction Vol4: Plumbing And Gas-Fitting, Heating And Ventilation, Painting And Decorating, Estimating And Calculating Quantities", by The Colliery Engineer Co. Also available from Amazon: A Treatise On Architecture And Building Construction.
299. Fig. 90 shows a good arrangement of heating and ventilating apparatus in a small frame dwelling. This house represents a class which is very numerous in the country and suburban districts. It is two stories high, except the part containing the pantry, which is a one-story addition.
The heating is performed by a hot-air furnace d, and the ventilation is secured by an aspirating chimney f. The draft in this chimney is aided by the heat emitted from the furnace smoke pipe e, which passes up through the center of it. In order to be durable, this pipe must be made of cast iron; common wrought-iron or galvanized pipe is worthless, being quickly destroyed by corrosion. The smoke pipe from the kitchen range should be connected into this pipe, so as to aid ventilation when the furnace is not in use.
The hot-air registers are located near the ceiling and in the extreme outer corners of the rooms; the foul-air outlets into the chimney are made near the floor. A second set of outlets near the ceiling are provided for use in summer time. It will be noted that the vertical hot-air ducts are carried up inside the room, instead of between the studding in the interior of the walls. The reason for this is that the walls are usually too thin to permit the use of a proper-sized flue, or to permit it to be properly protected against loss of heat. In the arrangement shown, a layer of good non-conducting material 1 inch thick is interposed between the wall and the ducts, as shown at a, b, and c. The other surfaces of the ducts are merely painted, or papered, or encased with thin wood, so as to present a satisfactory appearance, and also protect them from injury.
The best non-conductors for this purpose are either coarse wool or hair felt, or thin slabs of magnesia, sometimes called "mackite." If these are too expensive, a good sound pine board, free from knots or resinous spots, may be used instead. Paper will not afford sufficient resistance to the escape of heat, unless it be applied in many thicknesses, forming a layer at least half an inch thick. Common mortar or plaster is of very little use for this purpose.
300. Instead of connecting each vertical duct to the furnace by a separate pipe, as furnacemen usually insist upon doing, only one leader is used to supply each group; this should be covered with non-conducting material. The second-story flues are throttled at the bottom where they join the leader, so that they will not take an undue share of the hot air.
The hot-air register in the hall is placed in the floor, instead of in the wall, so that it may serve conveniently as a foot warmer, etc. The draft at this register is likely to be good, unless there is a considerable infiltration of cold air through the walls and around the outer door and windows.
The kitchen range is provided with a hood and a ventilating pipe k, which extends upwards to a point above the main roof and is provided with a proper cowl. This pipe should be provided with a damper, to prevent a back draft of cold air during the night time, when the fire is low, and to prevent loss of heat during cold weather. This arrangement adds greatly to the comfort of the kitchen, and more than repays for the extra outlay incurred.
301. The cold-air flue extends from the front to the rear of the house, and is provided with a tight shutter or slide at both ends, h and i. It is carried along overhead under the floorbeams, and is connected to the base of the furnace by inclined pipes g, which dodge the hot-air pipes and the smoke pipe.
In order to make a success of this system of ventilating and heating, the building must be made as nearly air-tight as possible. The walls must be made impervious at all points, and the circulation of the air between the joists and floors must be stopped. The windows and outer doors should be made wind-tight by means of packing or weather strips. It is essential, also, that the aspirating chimney f should be extended well above the main roof, and the top should be provided with a cowl, or so constructed that the wind will aid rather than impede the draft. The success of the whole system depends upon having a good draft in this chimney.
302. Hot-air furnaces are always objectionable, because they vitiate the air with gas to a greater or less extent; a much better quality of air can be secured by using a hot-water heater instead. The radiating coils may all be concentrated in one box, which is located in the same place as the furnace, and the warm air may be distributed by the pipes shown. Fairly good results may be achieved by using radiators in each room, but in this case each radiator should have an independent supply of fresh air, and should be encased so as to deliver the warm air at the top of the room, as described in a previous article.
303. Figs. 91 to 95 show the arrangement of flues and apparatus for ventilating and heating a suburban residence of moderate size. The ventilation is effected by an aspirating chimney, and the heating is performed by indirect hot-water apparatus.
The aspirating chimney a is 25 inches square inside, ana the draft is aided by a 10-inch smoke pipe from the boiler, which passes up through it. Another aspirating chimney b is provided in the kitchen for the use of the rear part of the house. This latter chimney is made 18 inches square, and the smoke pipe within it is 8 inches in diameter. The water closets are vented locally by this chimney instead of the other, so that effective ventilation may be had at all seasons of the year. Figs. 91 and 92 are both basement plans, one showing the radiator stacks i and hot-water piping, and the other showing the cold-air ducts k and the main foul-air flues which discharge into the central chimney. The flow pipes are shown in solid lines, while the returns are indicated by dotted lines. The boiler is shown at c.