Just as I was knee-deep in researching, testing, and learning all I could about electric space heaters, this letter popped up in my inbox. Dear Mary: I need your help to figure out how we can reduce our home heating bills. It’s killing us to pay so much to keep our house warm in the winter. We have a gas furnace, and where we live, the cost of gas has gone up more than 10 percent while, at the same time, the cost of electricity has gone down slightly. Our home is a two-story with a basement. Our kids are grown, so it’s just the two of us. My husband travels for his work, so I’m the only one here most of the time. Thanks in advance for your help! —Jeanine Dear Jeanine: An efficient and easy way to reduce your home heating cost is to heat only the rooms …