There are two types of heating, ventilation and cooling (HVAC) components that are available in variable speed models: compressors and blowers. Not all HVAC systems have them. Some of them have a single-speed compressor and a single-speed blower. If you’re thinking about upgrading your home’s HVAC system, though, you may want to consider a variable-speed compressor and a variable-speed blower.
What Is a Variable-Speed Compressor?
A variable-speed compressor is an air conditioning system compressor that’s able to operate at different speeds. Air conditioning systems rely on refrigerant to transfer heat out of the homes in which they are installed. When running your air conditioning system, the compressor will pump refrigerant from the evaporator coil to the condenser coil.
As the name suggests, a variable-speed compressor isn’t restricted to a single speed. Rather, it can pump refrigerant at different speeds. Variable-speed compressors can run at anywhere from 30% to 100% capacity. If you lower the thermostat by just a couple of degrees, the variable-speed compressor may run at a lower capacity. If you lower the thermostat by a significant amount – meaning you need more cooling power – it will run at a higher capacity.
What Is a Variable-Speed Blower?
A variable-speed blower, on the other hand, refers to an HVAC blower that’s able to operate at different speeds. HVAC systems contain a motorized fan that pushes the conditioned air into and through the ductwork. Known as a blower, it’s an essential part of all HVAC systems. You can find the blower in the Air Handling Unit (AHU) or furnace of your HVAC system.
Some HVAC systems have a single-speed blower that operate at a single speed. Other HVAC systems have a variable-speed blower that operates at different speeds.
Differences Between Variable-Speed Compressors and Blowers
Variable-speed compressors and blowers are both able to operate at different speeds. They will typically adjust their power output automatically based on the thermostat settings in relation to the indoor temperature. With that said, variable-speed compressors aren’t the same as variable-speed blowers.
The compressor is exclusive to your air conditioning system (or heat pump). It will only run while your air conditioning system is running. The blower, conversely, is part of your air conditioning system and furnace.
When you hear the word “variable-speed HVAC system,” it may refer to an HVAC system with a variable-speed compressor, a variable-speed blower or both. Variable-speed compressors are air conditioning system components that pump refrigerant at different speeds. Variable-speed blowers are motorized fans that blow the conditioned air into and through the ductwork at different speeds.