A hatchway cut through a roof is convenient when high chimneys are repaired or cleaned, especially when access to the roof is difficult. The hatchway should be located so that it will not be necessary to crawl over the roof to reach the chimney and so that a ladder placed on the attic floor will not be too steep for safe ascent. A watertight cover with hooks to prevent its blowing off is essential. Such a hatchway is best provided when the building is erected but can be readily built at any time.
A fireplace is ordinarily considered appropriate to a living room, dining room, and bedroom; however, basement, porch, and outdoor fireplaces are gaining in favor with the householder. Also public dining places, offices, etc., frequently have fireplaces for the comfort and for the air of informality they provide.
All fireplaces should be built in accordance with the few simple essentials of correct design given herein if satisfactory performance is to be realized. They should be of a size best suited to the room in which they are used from the standpoint of appearance and operation. If too small, they may function properly but do not throw out sufficient heat. If they are too large, a fire that would fill the combustion chamber would be entirely too hot for the room and would waste fuel.
The location of the chimney determines the location of the fireplace and too often is governed by structural considerations only. A fireplace suggests a fireside group and a reasonable degree of seclusion, and therefore, especially in the living room, it should not be near doors to passageways of the house.
The principal warming effect of a fireplace is produced by the radiant heat from the fire and from the hot back, sides, and hearth. In the ordinary fireplace practically no heating effect is produced by convection, that is, by air current. Air passes through the fire and up the chimney, carrying with it the heat absorbed from the fire; at the same time outside air of a lower temperature is drawn into the room. The effect of the cold air thus brought into the room is particularly noticeable farthest from the fire. Heat radiation, like light, travels in straight lines, and unless one is within range of such radiation, little heat is felt. Tests made by the Bureau of Agricultural Chemistry and Engineering showed that about five times the amount of air required for even liberal ventilation may be drawn into a living room by the operation of a fireplace. Such excessive ventilation may cause chilling drafts. Persons located at advantageous points in the room will be comfortable under such conditions, but those out of the radiation zone will not.
