Hot air distribution systems allow you to convert the fireplace into a very effective and cost-saving device for heating all over the House.Many home heating and cooling systems move air throughout the home using a forced-air distribution system. A gas furnace, oil furnace, and electric furnace all do this, as does a central air conditioner. Rather than repeat this information in each of the system guides, let's take a look at how air--no matter how it's made hot or cool--can be distributed efficiently.