Indirect Water Heaters
Indirect water heaters offer a more efficient choice for most homes, even though they require a storage tank. An indirect water heater uses the main furnace or boiler to heat a fluid that’s circulated through a heat exchanger in the storage tank. The energy stored by the water tank allows the boiler to turn off and on less often, which saves energy. Therefore, an indirect water heater is used with a high-efficiency boiler and well-insulated tank can be the least expensive means of providing hot water.
Also, these integrated or combination water heating systems not only can work with forced air systems but also with hydronic and radiant floor heating systems.