Heating in private buildings is supported by a boiler. For example, buying a boiler of St. Petersburg is not a problem, however, to create with heat losses? It is not good, entering the radiator, is lost where the sharp, since the building is not separated in the proper way. The number of energy spent on heating will be dependent on the insulation of the house. What means is much better insulation, due to this, there will be active costs. As a rule, the thermal power of the radiator is selected subjectively.