Packaged Dual Fuel When it comes to power management, a packaged dual fuel system is one of the best options a homeowner can have. Basically, a packaged dual fuel system uses an energy efficient heat pump for summer cooling and mild weather heating. When dropping temperatures begin to adversely affect heat pump efficiency, the packaged dual fuel system activates its gas furnace to keep the home comfortable. This flexibility can result in substantial savings, especially if your home is equipped with an outdated gas furnace and air conditioner. The key to getting the best out of a packaged dual fuel system is to make sure both the heat pump and gas furnace are high efficiency. The minimum requirement for a new residential heat pump is 13 SEER. Compared to older air conditioners, 13 SEER is not bad efficiency, but the better the heat pump’s SEER rating, the less energy you will use to get good air comfort. If you can afford it, you should invest in a system with a high SEER rating and the higher, the better. For cold winter heating, you want a packaged dual fuel system that uses a gas furnace with a high AFUE rating. 80% AFUE is, roughly, the industry minimum and, as with SEER, the higher you can get, the more money you will save over the long term. The closer your gas furnace AFUE rating gets to 100%, the less energy you need.