From: This Old House
By: Richard Trethewey
Q: I recently purchased a 1,146-square-foot home with a seven-year-old gas furnace rated at 80 percent efficiency. The rise in gas heating costs has me wondering if I should upgrade the furnace, or maybe even convert to a different type of fuel. Can you help me decide?
—Susan Cairns, Hilliard, Ohio
A: To make your decision, you need to weigh three factors: your furnace efficiency, the cost of fuel, and the “heating load” of your house—that’s the amount of energy required to maintain a steady 65-degree temperature indoors.