Figure 22.—Except for the registers and metallic sides and back, the appearance of modified fireplaces is like that of ordinary ones. An interesting effect is secured by the mirror—the reflection of the opposite wall appears like a recess over the mantel.
However, the nature of operation, with the unavoidably large quantity of heated air passing up the stack, makes the inherent over-all efficiency of any fireplace relatively low. Therefore, claims for an increased efficiency of modified fireplaces should be understood merely as constituting an improvement over the ordinary fireplace and not over stoves or central heating plants.
When a fireplace is being selected the kind of fuel to be burned should be considered; also, the design should harmonize with the room in proportion and detail (figs. [23] and [24]).
Figure 23.—A well-designed commercial mantel that suits the room. Since it is painted the same color as the walls, it does not focus attention, as the handsomely carved formal mantel or mahogany shown in [figure 37] is intended to do.
In colonial days, when cordwood was plentiful, fireplaces 7 feet wide and 5 feet high were common, especially when used in kitchens for cooking ([fig. 25]). They required large amounts of fuel and too frequently were smoky.
Where cordwood (4 feet long) is cut in half, a 30-inch width is desirable for a fireplace; but, where coal is burned, the opening can be narrower ([fig. 26]). Thirty inches is a practical height for the convenient tending of a fire where the width is less than 6 feet; openings about 30 inches wide ([fig. 27]) are generally made with square corners. The higher the opening, the greater the chance of a smoky fireplace.