The Real Difference between 80% Efficiency and 90% Efficiency

When it comes to heating and cooling the word energy efficiency is thrown around an awful lot.  Furthermore, we often here a lot of numbers accompanied with it…80%, 90%-what does it all mean?  Many of you might not be sure what the difference is between an 80% furnace and a 90% furnace-if there even is a difference.  Here is a brief explanation.

Though both an 80% efficiency furnace and 90% furnace will heat your home, there are some significant differences that you may want to think about it if you are considering a new furnace in the future.  The number ratings that furnaces come with are their AFUE percent (Annual Fuel Utilization Efficiency).  The percent represents how much energy from your furnace is actually going to heat the home, and how much of it is wasted.  Therefore, with an 80% efficiency furnace you are only receiving 80% of the heat that you pay for.  With a 90% efficiency furnace you are receiving 90%.  10% might not seem like a large difference, but at this time of year when we are consistently using our furnace, that 10% can really add up.

The other difference between an 80% efficiency furnace and a 90% efficiency furnace is how the furnace is vented.  80% efficiency furnaces have much high exhaust temperatures so they must be vented through the chimney via a chimney liner.  90% efficiency furnaces on the other hand vent at much lower temperatures so they are vented through PVC pipes on the side of the home.

All in all, the major difference between the two is how the 90% efficiency furnace really can save more money and efficiency than the 80% efficiency furnace.  If you are interested in learning more, please contact FLAME!