What is a “variable-speed furnace,” and what benefits does it confer?

The term “variable speed furnace” refers to an aspect of the furnace’s motor. These electrically commutated motors (ECMs) are more efficient, and lower maintenance, than other furnace motors. ECMs can run at different speeds, allowing for more precise control over the airflow in your home. This helps to achieve a better balance in your home’s humidity and temperature, creating a more comfortable indoor climate. This also compensates for common minor problems like blocked vents and dirty air filters. As an added bonus, they also tend to run more quietly than their single-speed counterparts. Although their initial cost is slightly higher, variable-speed furnace installation can be a worthwhile investment.