Variable speed and constant torque motors are both ECM. Variable speed will keep a constant cfm. If you're filter gets dirty, itll increase torque and rpm to maintain CFM. Constant Torque does what it says. If you're filter is dirty, its going to maintain its torque. But BOTH are electronically commutated motors.
I have a variable speed furnace, but in reality, it will only run at 5 speeds, even though it has the necessary circuitry to run at any speed. Mine is used with a two stage air conditioner and from the factory, it has two AC speeds, two heat speeds, and one fan speed preset into the system. Using switches on the unit, I can change the speed for any of these run modes, but it cannot be varied on demand by my two stage AC or the heater other than to select the different modes, which are esentially high and low for heat and for AC, and a setting for a low volume circulation only. Now with a two speed condenser, it really is necessary to use a furnace like this because once again, you need to have the ability to match the air flow to the different stages. I had an inverter based system where the condenser could change over an "infinite" range, then the blower would commicate with the condensor to match the speed of the blower and the pressure of the condenser (at least this is my understanding). Otherwise, my variable speed furnace can only run at one of five speeds, but I can manually set the speed for each stage using the controls on the furnace, but I have to go into my crawl space to do that and I think it is pretty complex because you need to be able to kind of get your drop in real time to avoid too low of an airflow to cause the evaporator to ice up .
Variable speed and constant torque motors are both ECM. Variable speed will keep a constant cfm. If you're filter gets dirty, itll increase torque and rpm to maintain CFM. Constant Torque does what it says. If you're filter is dirty, its going to maintain its torque. But BOTH are electronically commutated motors.
I have a variable speed furnace, but in reality, it will only run at 5 speeds, even though it has the necessary circuitry to run at any speed. Mine is used with a two stage air conditioner and from the factory, it has two AC speeds, two heat speeds, and one fan speed preset into the system. Using switches on the unit, I can change the speed for any of these run modes, but it cannot be varied on demand by my two stage AC or the heater other than to select the different modes, which are esentially high and low for heat and for AC, and a setting for a low volume circulation only. Now with a two speed condenser, it really is necessary to use a furnace like this because once again, you need to have the ability to match the air flow to the different stages. I had an inverter based system where the condenser could change over an "infinite" range, then the blower would commicate with the condensor to match the speed of the blower and the pressure of the condenser (at least this is my understanding). Otherwise, my variable speed furnace can only run at one of five speeds, but I can manually set the speed for each stage using the controls on the furnace, but I have to go into my crawl space to do that and I think it is pretty complex because you need to be able to kind of get your drop in real time to avoid too low of an airflow to cause the evaporator to ice up .
Thank you.
What is the difference between a 5 speed ECM motor air handler and that of a regular ecm motor?
On variable speed motors, how much will they slow down? If real slow how do we prevent coil freezing
Usually Depending On The Brand, They Slow Down To 65% Of The Full CFM Set At The Board. Thanks so much for reaching out.