According to the Feds, it's all about the R-Value. Whether you live in Alexandria, VA like I do, or you're in Phoenix, AZ, your home will be more comfortable and energy efficient with the right insulation. Insulation helps lower the cost of heating and cooling your home. Here's how: Heat travels. In the winter, heat flows out; in the summer, heats flow in. A properly insulated home reduces that heat flow, so you don’t use as much energy to heat your home in the winter and coo