Oil furnaces are a popular alternative to propane or gas furnaces. Oil furnaces burn a petroleum-derived hydrocarbon oil related to diesel fuel or kerosene. The oil is stored in a tank, sprayed onto electrodes and ignited. This spark is contained in a combustion chamber, which transfers the heat to a heat exchanger. This heats the air in the ductwork, which travels through your home to provide heat.
Oil Furnace Advantages
One of the most popular aspects of oil furnaces is their lifespan. Manufacturers usually guarantee ten years of heat from their furnaces, but most people report 15 to 20 years of service.
The efficiency of furnaces is measured by AFUE, which stands for annual fuel utilization efficiency. It is a rating of the percentage of fuel that is converted to heat. Oil furnaces are one of the most efficient models available, with an average of 83 percent annual fuel utilization efficiency. They are generally less efficient than gas heaters, however, and therefore long-term oil furnace cost tends to be higher than gas systems.
Additionally, oil furnaces are clean burning, with their exhaust neatly contained within the furnace. Gas furnace cost to operate tends to be low because the fuel is also fairly cheap, depending on your region, and in some areas an environmentally friendly mixture of fuel and biofuel similar to what cars use is available.
There is a simple system that can allow a homeowner to convert their furnace from petroleum to biofuel. Start with a B2 mixture, which is 2% biofuel to 98% petroleum. For the next fill up, do a B5 mixture with 5% biofuel. This can continue up to B100, which is 100% biofuel.
The only significant disadvantage to biofuel is that it’s hard on seals and rubber. Be sure to check the seals on your furnace regularly to make sure that they are intact.
Much of the biofuel that’s being developed for home use comes from corn and soybean. At present, the fuel is not available everywhere, but as it becomes less expensive, it will likely show up all over the country.
Oil Furnace Disadvantages
Oil furnaces are reliable, although there are longer lasting furnace options available. Check at your local supplier or ask an oil furnace contractor to find out if oil furnaces are best for your region.
While oil furnace emissions are contained and lower than other processes, leaks can occur so regular maintenance is required. Also, the contained exhaust requires maintenance to keep the furnace running efficiently.
Oil furnaces can be less convenient than electric furnaces or heat pumps because the fuel must be delivered to your residence.
Oil Furnace Cost
Initial oil furnace cost usually runs around $2,000-$5,000 for basic models. For more complicated installations, such as a more complex floor plan or hard-to-reach ductwork, oil furnace cost can reach $6,000-$10,000. For a general review of furnaces, see “Furnace Prices: Types, Taxes and Cost”.