Types of Central Heat
- Central heating is most often accomplished through a forced-air system involving a furnace and the distribution of heated air through a series of ducts throughout the house. Central hearing systems differ from more localized heating appliances in that they are capable of heating the entire house at the same time. As long as the furnace is properly installed and all the ducts are open, each room should receive roughly the same amount of heat. The primary differences with this type of central heating system is the fuel used to make it run.
- A gas furnace is fueled by either natural gas or propane. The indoor air flows around the heat exchanger, is heated and then circulated through the duct system. Another system of ducts returns air to the furnace where it is reheated, and the entire process starts over again. For venting purposes, additional air is drawn into the flue where it mixes with the hot exhaust gas before exiting through a chimney.
- An oil furnace uses oil burned in a combustion chamber to heat air. A fan or blower system helps to force this heat across an exchanger before it enters the duct system. A central heating system that uses oil requires more maintenance than a gas or electric furnace system. The filter should be replaced monthly, and you should hire a professional to service the oil furnace once a year.
- Electric furnaces are powered by electricity but work essentially the same as a gas furnace. Electric current passes through a heating element that warms the air passing above it. This heat causes the air to rise into the ductwork system where it is then distributed throughout the house. Electric heat furnaces use a system of heat transfer known as conduction and convection to work.
- The heat pump is another type of central heating appliance. A heat pump draws all the available warmth from the outside cold air and deposits it into a coil located on the inside of the house. When the temperature drops below a preset level, the heat pump picks up the heat from the cold air outside and expels it inside the home. The air that is expelled by a heat pump is warmer than the outside air from which it came because it has been generated by pressurizing the refrigerant.
- Central heat can also be supplied throughout a house with a geothermal heating system. Warm air is drawn from the ground through refrigerant lines only to be deposited inside the house through a process that closely resembles that of the heat pump. Warm air is released into the house where it rises only to return to the air handler system through another duct system.