Mid-Efficiency and High-Efficiency Oil Furnaces
As was mentioned in Chapter 11 (“Gas Furnaces”), the government and furnace manufacturers have significantly improved the heating efficiency of residential gas furnaces. Similar improvements have been made in oil furnace technology. Two widely used methods, the AFUE measurement and the Energy Star program of the United States Environmental Protection Agency (EPA), are described in the sidebars. A furnace that meets the minimum efficiency requirements of these ratings is referred to as a high-efficiency oil furnace.
AFUE Rating
The energy efficiency of an oil furnace is measured by its annual fuel utilization capacity (AFUE). The AFUE ratings for furnaces manufactured today are listed in the furnace manufacturer’s literature. Look for the EnerGuide emblem for the efficiency rating of that particular model. The higher the rating, the more efficient the furnace. The government has established a minimum rating for furnaces of 78 percent. Mid-efficiency furnaces have AFUE ratings ranging from 78 to 82 percent. High-efficiency furnaces have AFUE ratings ranging from 88 to 97 percent. The traditional oil furnaces have AFUE ratings of approximately 60 to 65 percent.
Energy Star Certification
The Energy Star Program is an energy performance rating sys- tem created by the EPA to identify and certify energy efficient products, including furnaces, boilers, heat pumps, and air conditioners. A broader description of the program is given in Chapter 11, “Gas Furnaces.”