Multicoil Water Heaters
Sometimes the size of a structure or its use will result in a greater demand for hot water than a conventional water heater can supply. When this is the situation, it is recommended that a multicoil, or large-volume, water heater be installed. These water heaters resemble instantaneous heaters externally but differ by containing more than one heating coil. The separate heating coils are connected to manifolds operated by a thermostat inserted in the storage tank.
Because multicoil water heaters have large storage tanks, they are suitable for use in restaurants, clubs, and structures of similar size and use.
Multiflue Water Heaters
The multiflue water heater was developed for commercial uses to satisfy the need for greater heat transfer surface and to efficiently remove the higher volume of noncombustible gases resulting from the higher gas inputs. The dia- gram of a gas-fired multiflue water heater is shown in Figure 4-5. Compare this with the diagram of the oil-fired multiflue water heater illustrated in Figure 4-4. Each is essentially a vertical fire-tube boiler enclosed in an insulated jacket.
Multiflue water heaters are characterized by a relatively high hot-water recovery rate. These heaters are used in conjunction with auxiliary storage and
