Compared to a conventional single speed furnace a variable speed furnace performs better and uses about two thirds less electricity.
Retrofit variable speed furnace motor.
More efficient motors are available evergreen for retrofits but they pretty much function like standard multi speed psc motors.
According to the manufacturer s documentation your furnace should have a 3 or 4 speed blower motor.
Is it louder when heating cooling.
The problem is the furnace control module doesn t use a separate speed when the unit is running in continuous fan mode.
The higher the seer the lower your utility bills.
Variable speed furnaces are able to run at a range of speeds rather than one speed as traditional furnaces do.
Since 1985 furnace manufacturers have used higher efficiency variable speed bpm fan motors also known as electronically commutated motors or ecms in some high end residential furnaces.
During the cooling mode variable speed systems typically result in an efficiency gain of about 1 seer seasonal energy efficiency ratio.
Should be if circ is on lowest speed there is no way to retrofit an existing furnace with an variable speed ecm.
In recent years new furnaces with bpm motors have gained market share.
And while not all contractors consistently offer ecms those who do often report increased profits as well as improved customer comfort and satisfaction.
Throughout operation the furnace monitors incoming data from your hvac system to automatically make blower motor speed adjustments.