What is the most energy efficient furnace?


80 AFUE Furnace Chart 211x300

The most efficient Furnace you can buy is a 98% modulating variable speed furnace.  Almost every manufacturer has a variation of this type of furnace.  With that said this is one of the most expensive to buy and install.  Also, not every home can have this style of furnace due to various factors like duct system design.

Location of Furnace

Your duct system design may not be ideal for a variable speed blower.  If your ductwork is undersized for your house, the furnace will be very loud and your new furnace’s life expectancy may be reduced.

Furnace Energy Efficiency Explained:

You probably hear terms like 80%, 90% and other percentages mentioned when you start looking at replacing your furnace.  What exactly does this mean?  AFUE stands for Annual Fuel Utilization Efficiency.  Essentially you can equate this to the gas mileage for your furnace. The higher the percentage the higher the energy efficiency.

For example, an 80% AFUE means the furnace output is 80 BTUs of heat that goes into your home for every 100 BTUs of natural gas being used and 20% wasted heat in the exhaust.  A higher AFUE will result in better efficiency.


Now that you understand more about energy efficiency you can feel more confident about your options and find a furnace that has an efficiency range that meets your comfort needs and your budget.  It is very important to know that most manufacturers have a wide range of efficient models.  High-efficiency furnaces will be more expensive than standard 80% efficiency units.  As technology advances heating and cooling equipment becomes more and more efficient.  Also, efficiency standards will continue to rise.  The 60-70% furnace you’ve had for 20+ years is no longer available.  Talk to your HVAC professional to evaluate what type of energy-efficient models would work best with your home needs and layout.

Remember regular furnace inspections and maintenance can reduce your emergency furnace repairs down the road.

Download our free furnace buying guide:

furnace-buying-guide-small-thumbnailThis guide was designed to provide you with valuable information when replacing your furnace. If you are considering replacing your furnace get all the information you need to make an informed decision.