Although gas-fired furnaces are the most common type, oil furnaces remain popular in areas with limited access to natural gas, such as the Northeast. Oil-fired furnaces have lower annual fuel utilization efficiency (AFUE) ratings than gas furnaces on average, although some models can achieve an AFUE of 90 percent or more. High efficiency oil furnaces can qualify for a federal tax credit; additional rebates or credits may be available from state governments or utility companies in some areas. Along with lower fuel costs, high-efficiency oil furnaces have lower carbon emissions. Although upgrading an older 56 percent AFUE gas furnace to a 90 percent AFUE furnace will reduce CO2 emissions by 1.5 tons per year, the same upgrade on an oil furnace will reduce CO2 emissions by 2.5 tons.
We found almost no sources that focus specifically on oil-burning furnaces. However, several sites that discuss the pros and cons of high-efficiency furnaces cover gas- and oil-fired models. These include government websites such as EnergySavers.gov and EnergyStar.gov, environmental sites like National Geographic's TheGreenGuide.com and general energy-saving sites like the American Council for an Energy-Efficient Economy.
Although this article does not focus on oil-fired furnaces specifically, it does compare low-, mid-, and high-efficiency heating systems and offer advice on whether to choose a high-efficiency unit. A table shows the possible cost savings of replacing an older, inefficient furnace.
Review: Furnaces and Boilers, Editors of EnergySavers.gov, Updated Oct. 5, 2010
This article touts the energy-saving benefits of high-efficiency furnaces, including gas- and oil-fired models. It notes that the environmental benefits of choosing a more efficient furnace are even greater with oil than with gas.
Review: Furnace Buying Guide, Tara Snyder, March 2010
3. American Council for an Energy Efficient Economy
This article outlines the benefits of high-efficiency furnaces, including gas- and oil-fired models. This site has lots of information relating to energy-efficient appliances and calculating your return on investment.
Review: Heating, Editors of American Council for an Energy-Efficient Economy
This page has information about the federal tax credits for energy-efficient heating and cooling systems. Elsewhere on this site, readers can also find a tool to research additional state and municipal rebates.
Review: Federal Tax Credits for Consumer Energy Efficiency, Editors of EnergyStar.gov
This article discusses ways in which an existing oil-fired boiler can be retrofitted to improve its efficiency. However, it notes that simply replacing the furnace with a higher-efficiency model may offer greater benefits.
Review: Oil-Fired Furnaces and Boilers, U.S. Department of Energy, Updated Oct. 5, 2010