Heating apparatus using useless heat for reducing oil

A heating apparatus comprising a boiler adapted to burn an energy source while discharging exhaust gas produced when the energy source is burnt, the boiler including an exhaust port, and a distribution board, the apparatus using waste heat to reduce the consumption of the energy source while being environmentally friendly, further comprising:

• at least one flue connected to the exhaust port of the boiler, the flue extending through an indoor space, and having a discharge port arranged outwardly from the indoor space;
• at least one fan unit installed in the flue, and adapted to forcibly move, through the flue, exhaust gas generated from the boiler while containing a large amount of noxious substances, thereby discharging the exhaust gas into the atmosphere after filtering the exhaust gas to contain a reduced amount of noxious substances, using a mist filter formed in the flue due to a temperature difference between the flue and the exhaust gas, or without any filtration of the exhaust gas by the mist filter;
• and
• at least one water drainage port provided at the flue.