Variable Speed Furnace Fan Retrofit

Better airflow control means a better balance of temperature and humidity.

Variable speed furnace fan retrofit.

While not all contractors consistently offer ecms those who do often report increased profits as well as improved customer comfort and satisfaction. The control module only uses two speeds one for cool and one for heat fan. There are many reasons for choosing a variable speed furnace but the main reason is comfort. The higher the seer the lower your utility bills.

In addition to better energy efficiency and temperature control variable speed furnaces deliver better indoor air quality as a result of varying blower motor speed. But over the years several manufacturers have developed variable speed electronically commutated motors ecms specifically designed as retrofit replacements for faulty psc motors. For refrigeration evaporator fan motors. This is not new technology said christopher mohalley master ecm trainer at regal beloit.

The term variable speed furnace is used to describe furnaces that have a variable speed blower motor. Running the heating system s fan continuously allows the furnace s blower motor to continue air circulation even when heating is not required. The evergreen im is a variable speed permanent magnet brushless dc motor the same type of motor used in furnaces equipped with an ecm. Either replace the furnace with one equipped with a variable speed blower or stick with single stage equipment.

A temperature based variable speed fan control may cause problems especially during defrost cycles. During the cooling mode variable speed systems typically result in an efficiency gain of about 1 seer seasonal energy efficiency ratio. The problem is the furnace control module doesn t use a separate speed when the unit is running in continuous fan mode. 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.

These blower motors are the motors that move air through the ductwork in your home. These speeds are used by a contractor to adjust airflow to the proper amount. Temperature rise declines as the outdoor temperature drops. The term variable speed refers to the furnace s fan motor which moves at different speeds to precisely control the flow of heated and cooled air throughout your home.

Furnaces without variable speed technology use a simple motor with multiple speed settings. Compared to a conventional single speed furnace a variable speed furnace performs better and uses about two thirds less electricity. In recent years new furnaces with bpm motors have gained market share. When the r g circuit is made the blower motor operates on heating speed.