On October 31, the Department of Energy will publish a final rule requiring a 13 percent efficiency improvement for non-weatherized natural gas furnaces, the most common type in the United States, starting in 2013. The proposed rule comes despite intense opposition from the natural gas industry, which says the standards will drive consumers to electric furnaces, and will be open to a 110-day comment period. The DOE defended the version of the rule that was issued in June by restating that they found no reason to abandon the final rule given industry opposition.