Output of the motor can be adjusted by signals from a controller or permanently programmed to advance through a range of speeds during each on cycle of the furnace.
													
																	Energy efficient furnace fan motor. 
								
	
		
	
																	Variable speeds unlike an on off psc motor a furnace ecm motor can operate at a range of outputs between zero and 100 percent. 
																	High is sometimes used when the fan switch on a thermostat is on as well as when central air conditioning ac is running. 
																	If you have a builder s grade or older system then it may cost you as much as 10 12 a month. 
																	Typical psc motor operation. 
															
													
								
	
		
	
																	These motors are intended to be installed by a qualified hvac technician. 
																	If you have a newer energy star rated furnace it will have a variable speed motor that is designed to run all the time. 
																	Here are some of the advantages to upgrading to a furnace ecm motor instead of sticking with the original equipment psc model. 
																	Exact energy amounts vary based on the size of the fan s motor but most whole house fans use between 120 and 600 watts according to the national renewable energy laboratory but this is still much less energy than a central air conditioner uses. 
															
													
								
	
		
	
																	High efficient furnace blower motors utilizing ecm technology ecm electronic commutated motor is a brushless dc motor with a permanent magnet rotor and a built in inverter. 
																	They are also more expensive. 
																	After july 3 2019 residential furnace manufacturers must include energy efficient electronically commutated low wattage motors ecm s on their furnace fans instead of the permanent split capacitor psc induction blower motors normally used. 
																	Dc motors are more efficient than ac motors.