Heat pumps practical for cooling, heating and reducing energy use and costs

Is it possible to reduce your energy bill and carbon dioxide emissions and get air conditioning for a home that didn't have it, all at the same time?

Sometimes it is. Changing your home's climate control system to a heat pump, from the typical Washington combination of a gas furnace or electric resistance units and no air conditioner, may reduce your energy costs significantly even though doing this adds air conditioning. You are likely to save more energy during the heating season while the system is heating, than you'll use during the short northwestern cooling season while the system is run...