When the price of fuel oil spiked a couple of years ago, Erin Holvoet and her husband, Kristian, began to search for a cheaper way to heat their drafty, 100-year-old house on a country road near Phoenixville.
A stove dealer suggested coal.
"Coal?" Holvoet recalls thinking. "Nobody heats with coal. Not anymore."
Well, a small number do. And that number now includes the Holvoets, who have joined the one-tenth of 1 percent of Americans who still employ coal as their primary heating source.
The very up-to-date couple - she's a statistician, he's a software developer - say they have saved hundreds of dollars by installing a stove that burns breakfast-cereal-size pieces of coal in a corner of the living room and allowing the hot air to rise throughout their three-story house.
They now fire up the oil furnace in the basement only on the most frigid days, just to give the coal stove a little help.
Eli, 5, the older of the couple's two sons, says it gets chilly when he takes a bath. But he loves to bundle up in a towel and run downstairs. "I stand by the stove," he says.
Many Americans of a certain age - those who grew up during the Depression and World War II - can remember shoveling coal or carrying out the ashes as a daily childhood chore. Those who misbehaved were threatened with a lump of coal in their Christmas stocking, discipline that dated from the time of Charles Dickens.
Pennsylvania was then, and is now, one of the great coal-mining states - the world's primary source of anthracite (hard coal) and a major producer of the sootier bituminous (soft coal) used predominantly by the steel and electric-power industries.
In 1940, according to census data, 86 percent of Pennsylvania residents heated with coal. Seventy-one percent of New Jersey residents and 55 percent of homeowners nationwide used it to keep the home fires burning.
Today, Pennsylvania ranks No. 1 in the percentage of residents who burn coal. West Virginia is second; Wyoming, third. But the numbers are minuscule all around.
The 2000 census found that just 1.4 percent of Pennsylvanians heated with coal. The finding of the 2010 census is not yet available. (Usage in New Jersey is so low that, percentage-wise, it came out as zero.)
Today, more than half of American households use natural gas, a third use electricity, and close to 10 percent use oil.
J. Scott Roberts, deputy secretary of the Pennsylvania Department of Environmental Protection, told a legislative committee in April that, despite cost advantages, coal use for home heating will continue to decline.
"New homes are not being designed for coal heating," he said.
Roberts also cited a newly emerging reason for coal's decline - the cheap competition that will be provided by the natural gas now being taken from Pennsylvania's vast Marcellus Shale.
"Anthracite coal may be a traditional or sentimental choice for home heating," he said, "but tradition and sentiment will not support growth in the industry."
An October comparison by the U.S. Energy Information Administration showed that coal was the cheapest major fuel. Electricity was most expensive, followed, in descending order, by kerosene, propane, oil, and natural gas.
For most users, the appeal of coal is price. It isn't convenience.
Modern methods aren't as labor-intensive as in the shoveling days of yore. But you still have to pick up, or order, the coal. You have to load it into a hopper. And you still have to carry the ashes.
Walt Hiriak, 87, a World War II veteran, recalls that the furnace of his youth was a hungry beast that had to be fed twice a day.
Three years ago, in moving from Gilbertsville to Furlong in Bucks County, he bought a four-bedroom house from the 1970s in which a previous owner had installed a furnace that could burn either oil or coal.
He decided to try coal. This year, he paid $1,200 to have five tons delivered. The dump-truck driver dropped it into a hopper in the basement.
"That lasts me from about the middle of December until the end of March," Hiriak said. "It's all automatic. All I have to do is empty the ashes once a day."
The Holvoets, near Phoenixville, get their coal by the bag from Lutz Coal & Wood, near Skippack, one of the few dealers in the southeastern corner of the state. That's where Erin Holvoet was on a recent afternoon.
She arrived in the family's van, with Eli and his brother, Sam, almost 2, strapped in in the back. She stopped at the office, a small hut, and went in. A coal fire burned in the stove.
She paid $96 for eight 100-pound bags of anthracite, then drove to a shed around back. Mounds of coal and other materials - stone, mulch, wood - stood like giant anthills in the yard.
She popped the hatch. An attendant picked up the bags and dumped them into the back of the van. The rear springs sagged from the assault.
A few days later, at home, the bags lay sprawled atop one another, like a pile of NFL linemen, on the side porch. The house sits on the edge of Port Providence, a rustic village beside the old Schuylkill Canal.
Inside, Eli and Sam were finishing dinner. The main floor, with kitchen, dinette and living room, was a cozy 75 degrees-plus.
The family paid $5,000 for the stove, the size of an old TV console, and feeder system. The stove is vented through the wall of the living room, not through a chimney. It burns anthracite that has been chopped into small pieces. From the outside, you can hardly see smoke.
Kristian Holvoet, 41, said that all he had to do was load the hopper, which takes 95 pounds of coal and automatically feeds the stove. When the weather is coldest, they can add coal daily.
The cinders get carted out with the trash. In the snow, they're better than rock salt for making a non-skid surface.
Once the stove is lighted in the late fall, it burns until spring. The Holvoets said they can leave home for a day, or more, without worrying.
If there is grime on the carpet, they said, it was from having two energetic boys in the house.
"It's only as dirty as you make it," Kristian Holvoet said of coal heating.
"I don't know that it's for everybody," his wife said. "But it's really good heating, it's cheaper - and it's cozy."