Here's a quick look at the most common types of heating systems:
- Forced-air systems: Heats air as it passes through the furnace. A blower and a system of ducts take the warm air throughout the house, and then back to the furnace.
- Hot-water (hydronic) systems: Water gets heated in the boiler and is then circulated through pipes to radiators or convectors. The water then returns to the boiler to be reheated and begins the journey again. The water can be circulated either mechanically through the use of circulator motors (pumps) or via gravity, as is common in older homes.
- Steam systems: These resemble hot-water systems, except that the water in the boiler is heated until it becomes steam and can travel under its own pressure through the pipes to radiators. Steam radiators get much hotter than water radiators and are therefore smaller. They should be covered to prevent burn injuries.
- Electric systems: Use electrical resistance to generate radiant heat in baseboard units, or in cables embedded in the ceiling or floor.