please give me the basic idea.
There can be various types of heating systems : 1. Heaters directly installed across the path of the air 2. Hot water heaters exchanging the heat with the air 3. A heat pump reverse to refrigeration cycle where sink is the heated area and source is the atmosphere.
Fuel is used to heat piping or tubing that has some heat transfer medium (air, water, steam) enclosed in it. For air, it is just circulated through the house. For water or steam, it is piped into heat exchangers that are used to heat the air. The cool water or condensed steam is returned from the heat exchanger (a radiator or convector) to the furnace where it is reheated. Electricity is also used for heat. The simplest is resistance heat which just has a heater that gets hot when current flows through it. That heats the air in the house. There are also heat pumps which operate like an air conditioner in reverse to take heat from outside and increase its temperature by the compressor. The higher temperature heat then heats the house. Heat pumps usually provide more heat for the energy they use than resistance heat unless it gets really cold outside (<20 F). Most heat pump systems have resistance heat built in for those cold days.
