Gas savings can also be realized with higher efficiency units and variable speed fan motors.  A properly sized and high efficiency furnace combined with home energy upgrades will ensure your system is working at its highest potential.  Furnaces that sit on return plenums inside or in garages can often be easily accessed during installation to properly seal the ductwork.  Other times older furnaces that sit in dedicated closets can be insulated to protect the rest of the home from unnecessary heat gain from the attic.  At Green ID we look at the big picture and will offer whole home solutions that really work.  Gas leaks are checked with a combustion sniffer and CO levels are measured whenever possible. 

The table below shows estimated savings with high efficiency furnace upgrades based on $375 gas bill per year in Phoenix.