Better go out and buy a gas fireplace and stove soon before federal regulations make them more expensive. Federal officials are looking to regulate the energy usage of fake fireplaces as part of the Obama administration’s effort to fight global warming.The Energy Department has proposed new regulations that would mandate that “gas-fired hearth products” like decorative fireplaces and stoves be more energy efficient and produce fewer carbon dioxide emissions. DOE says its rule would save $165 over the lifespan of the average hearth and reduce carbon dioxide emissions by 11.1 million metric tons through 2030.The major change DOE demands is...