Range boilers are usually placed alongside the kitchen range in a vertical position where they rest upon a cast iron boiler stand. When range boilers are placed horizontally they usually rest on iron brackets attached to the top or back of the range. Horizontal storage tanks are generally supported by iron bands attached to the iron floor beams above. When they are set vertically they are supported by iron frames or legs. The best way to set a hot water tank, however, is to let it rest firmly on the cement floor of cellar or basement where it is located. If there is no cement floor, a flag stone or cement base can be provided for both the heater and tank to rest upon.

Fig. 131

Proportioning Size Of Tank And Boilers

Range boilers and heater tanks are used to store water heated by water-back or water heater during periods when hot water is not being drawn. It thus provides a supply to draw upon when hot water is used faster than it can be heated by the waterback or heater. Also, it allows a smaller heater to be used than would be the case if water were drawn direct from a heater and had to be heated as fast as used.

The size of a tank for storing hot water should bear a certain relation both to the capacity of the heater and to the number of gallons of hot water used daily. If the tank is too large for the heater there will never be a supply of hot water in the tank, and if the tank is too small the water will become heated to above 212 degrees, and when released from the faucet will flash instantly into steam; also in many cases it will cause a rattling, snapping sound in the heater.

An ordinary range has a waterback with a heating surface of about 110 square inches exposed to the fire. A waterback of such a size will ordinarily heat sufficient water for an average size family. It can be used in connection with any size of boiler, from 35 to 50 gallons capacity. The size of the boiler should depend upon the probable amount of hot water that will be used daily. If the water is used uniformly throughout the day, and almost as fast as it is heated, a 35-gallon boiler will be sufficiently large. If, on the other hand the water is drawn intermittently, with long intervals between drafts, a larger boiler should be used to store the water heated during the intervals.

In public and semi-public buildings, where large quantities of hot water are used, the heater must be large enough to heat water as fast as it will probably be used during periods of average consumption, and the hot water tank should be large enough to store sufficient water for one hour's maximum supply. For instance, in an apartment house where the probable maximum consumption of hot water would equal 250 gallons per hour, and the average consumption 125 gallons per hour, the heater should be capable of heating at least 125 gallons per hour, and the tank should have a storage capacity of 250 gallons.

The size of hot water tank required for a large building depends so much upon conditions peculiar to that building that a satisfactory rule applicable to all cases cannot be formulated. An approximation that will be found sufficient for most apartment houses is to allow 5 gallons capacity in the tank for each inmate the building will accommodate. For large hotels and public institutions that have accommodations for 300 and more people, a smaller allowance, about 4 gallons per capita, will be found sufficient.