We have gotten quotes on replacing our furnace. How important is the efficiency rating? Two quotes have 80,000 BTU furnaces but one is for a 70,000 BTU furnace. Is there a big difference? Also, all units were dual stage but one was with a variable speed motor, how important is that?
Rodney, Bartlett, IL
The efficiency ratings are very important since they tell you how much of the heat from your fuel gas will be supplied to the house. The lowest is now 80% which means that 20% of the heat that you pay for is sent up the chimney. Many people are installing the higher efficiency furnaces with ratings of 5% or more, which limits the waste of produced heat to 5% or less. Another feature of the 95% efficient unit is that it does not take air from inside the house to feed the combustion in most installations, so your house feels less drafty and more comfortable. This makes humidity control in the winter much easier too, thus providing much higher comfort levels in the home. And, of course, you are spending less money on energy at the same time. In northern climates the higher efficiency unit is by far the best option. A comfort specialist can advise you of available tax credits and/or local utility rebates. The difference between a furnace producing 80,000 BTU or 70,000 BTU may mean the smaller one would not properly heat your home on the coldest day. The heating load of your home should be determined first, and the furnace should then be selected that best matches the heating requirement. A comfort specialist can advise you of heating requirements for your home to help you select a furnace. The variable speed motor is the most energy efficient motor available, and it is superior since it is a smart motor and is configured for your system. It ensures that the airflow will always be correct for the stage of heat in which it is operating, as well as for the cooling requirement, if you have air conditioning on this system. This also provides maximum comfort at the best efficiency from your heating and cooling system. I suggest you contact a professional HVAC contractor, such as the ARS/Rescue Rooter branch in Itasca, IL at (630) 438-6900, for assistance with your decision.