Combination Boiler and Indirect Water Heating
Combination boilers and water heaters provide both space heat and hot water. Combination units operate the same way as standalone boilers or water heaters; they differ in that combination units often require extra equipment in order to serve dual roles.
Boiler-based combination systems are most effective in single-family homes located in northern climates. Water heater-based combination systems are most effective in small residences, such as apartments or condominiums, as the heater might not be large enough to provide enough space heat for larger single-family homes.
III Equipment Options
Codes may require the use of a heat exchanger so that potable (drinking) hot water does not mix with water used in the space heating equipment; mixing is not an issue for indirect water heaters. Space heat can be distributed by a radiant floor, fan coil, baseboard, or a combination of the above.
1. Equipment Manufacturer Database
2. Natural Gas Efficiency Consortium