Furnace efficiency.

Today, new furnaces are generally between 80-96% efficient. If a furnace is 96% efficient, it simply means that 96% of the energy that goes into the furnace is converted into heat. Older furnaces or furnaces that are in homes that are 15 years old or more, can be as low as 60% efficient. Thus, upgrading to a 96% efficient furnace can reduce heating bills by 30% or more.

Typically, in colder weather states such as Wisconsin, a 90%+ efficiency furnace is recommended. The only exception is in vacation homes that are not occupied for extended periods of time during the winter.

Furnace fans.

Many people do not realize that there are options in the types of furnace fans that are available. The furnace fan runs anytime the heating or cooling system is conditioning the air. However, many people choose to run their fan continually. This provides a constant filtration of the air, providing considerably better indoor air quality for you to breathe. Additionally, running the fan all of the time will help even out the temperatures between rooms and provide a constant air flow which results in a much more comfortable living environment. A single speed fan costs approximately $210/year to run continually, where a variable speed fan costs approximately $30/year to run continually. Additionally, a variable speed fan is much quieter and provides a more gradual increase airflow.

Single Stage vs. Two-Stage Furnace.

Most furnaces either have all of their burners lit or all turned off. However, over 80% of the time, it is not necessary to have all of the burners of the furnace lit to meet the heat demands of the home. Having all of the burners lit when it is not necessary causes wasted energy and an uncomfortable living environment.

Choosing a new furnace is not an easy task, and it is a choice that you will live with for the next 15+ years. Consider each of the major options carefully to choose a furnace that is going to meet the needs of your family now and in the future.


Bob Beisbier, owner of BK Home Inspection, is a Certified Master Home Inspector who has been providing professional and thorough home inspections in southeast Wisconsin for over 12 years. Bob is Infrared certified, DILHR Certified, and provides Home Energy Tune-ups, Environmental Data Reports, Pre-sale Home Inspections and Pre-offer Home Inspections.