Measuring the efficiency of used oil furnaces is difficult because a clean furnace burns more efficiently than a dirty one. Ash residue from the combustion of used oil builds up inside the combustion chamber and gradually reduces the amount of heat transferred from the combustion chamber to the room air. This means that the precise efficiency level of any used oil furnace is constantly changing depending on the amount of ash build up, in addition to other factors.

When making a comparison between equivalent competing furnaces over a proscribed number of hours, you will find a striking difference with a Clean Burn furnace – a considerably lower stack temperature. The lower the stack temperature; the greater the furnace efficiency.

A low stack temperature means less heat is being lost out the stack and more heat is radiated out to the room environment -- this all due to Clean Burns innovative, heavy construction, multi-pass heat exchanger.