#6 Fuel Oil Facts
29 November 2009
Number 6 fuel oil is used primarily for heating large buildings like commercial buildings and apartment buildings, so unless you are familiar with large-scale heating, chances are you have not heard of it. Home heating oil is known as number 2 oil which is the same thing as diesel used in cars and trucks, except a little dirtier. So what is number 6? Literally, it is the bottom of the barrel. If you remember fractional distillation from high school science you can visualize what happens with crude oil when it is refined. The cleaner fuels rise to the top, and the heavy ones fall to the bottom. The only product heavier than number 6 in the distillation process is asphalt.
Number 6 is known as residual fuel oil. It is dirty, heavy, difficult to handle, and cheap. It is high in sulfur and has the highest proportion of carbon, which becomes CO2 when combusted, of any fuel type available. Number 6 is also heavy, or viscous. Handling it is like handling tar, in fact it needs to be heated to make it move. The trucks that deliver it are heated, the tanks that store it in the basements of buildings are heated, etc.
This of course begs the question of why it is used. The answer is simple...it is cheap, and it has a high BTU per gallon content. New York City has many older buildings that are trapped in the number 6 heating infrastructure. It is unfortunate. It is also literally a "dirty secret." Few tenants who are judicously recycling, watching energy consumption, and reducing their carbon footprint realize they are living in a building with technology only slightly better than a coal plant.
What to do? Seems to us if you could reduce your consumption by 15% to 20% that would be a great start.
