WASHINGTON (AP) – The Energy Department on Friday proposed to let states decide whether to increase the required efficiency of residential furnaces much beyond what’s now on the market, rejecting calls for significantly tougher national standards.

With consumers facing high heating bills each winter, furnace efficiency has become an increasingly important matter for both keeping down costs and saving energy.

A proposed standard issued Friday by the Energy Department would require gas furnaces to meet an 80 percent efficiency standard, essentially no change from the minimum efficiency levels already met by virtually all new furnaces sold.

The department rejected a call by energy efficiency advocates to boost the minimum standard for gas furnaces to 90 percent efficiency. It argued that such a standard might not be needed in warmer regions.

Instead the department’s proposal calls on states decide whether they wanted the tougher fuel-saving requirements.

“This long-overdue proposal misses the opportunity to bring home heating into the 21st Century,” said Katherine Kennedy, attorney for the Natural Resources Defense Council, an environmental advocacy group.

The Energy Department’s current furnace standards have been unchanged since 1987, and three New England states – Vermont, Rhode Island and Massachusetts – have adopted more stringent standards in the past few years.

But those states have not been able to move forward without waivers from the department, said Michael Stoddard from Portland, Maine-based Environment Northeast, a nonprofit advocacy group that specializes in energy policy.

The Energy Department’s proposed rules should make it easier for states to obtain waivers to increase furnace standards, Stoddard said.

In Maine, a proposal to increase furnace standards was rejected by the House two years ago; last year, the proposal didn’t make it out of committee, said Beth Nagusky of the Maine Office of Energy Independence and Security.

“In Maine, consumers are for the most part buying pretty good furnaces and boilers, but there’s still some portion that’s buying the bottom of the barrel,” Stoddard said. “That’s too bad. They’re trying to save a few bucks up front, and they’re going to lose thousands of dollars over the life of the equipment.”

Some people were disappointed that the Energy Department didn’t adopt stringent across-the-board standards for furnaces.

The proposed rule would modestly increase the current furnace standards but they would produce little natural gas savings from what’s already in use, said Andrew deLaski, executive director of the Boston-based Appliance Standard Awareness Project.

DeLaski said there is some improvement in requirements for oil furnaces, but that “the big opportunity” for energy savings would be in improving gas furnaces.

There are 3.2 million new gas furnaces sold annually, compared to 125,000 oil furnaces, he said. The rules would become final after a comment period and go into effect in 2015.