What is a variable-speed compressor?
A variable-speed compressor, also called an inverter compressor, is the part of a modern heat pump that lets it run at many different speeds instead of just "on" or "off." Rather than blasting at full power and then shutting off, it modulates, running long and low at a steady output that holds a consistent temperature while sipping electricity.
Why it matters for comfort and efficiency
Older single- and two-speed systems cycle hard, which causes temperature swings and wears the equipment out faster. A variable-speed system matches its output to what the home actually needs at that moment, so it stays quieter, holds temperature more evenly, and runs more efficiently. Much of the efficiency captured in a system's SEER2 and HSPF2 ratings comes from this.
The thermostat catch
There's a trade-off most homeowners never hear about. A fully variable-speed heat pump needs a matched control to actually run variable-speed in the first place. Stephen Lake explains why:
"A modern heat pump is fully variable speed. And so you need what's called a communicating thermostat." (listen, 36:35)
Pair a variable-speed system with a generic on/off smart thermostat and it can drop down to single-speed operation, which gives back much of the efficiency and comfort you paid for. Jetson Air ships with controls built for variable-speed operation.
To see what a fully variable-speed system would cost for your home, see what a variable-speed system runs for your home from your address, no in-home visit needed to start.
Common questions
Is variable-speed worth it? For most homes, yes. It's the main reason modern heat pumps are quieter and more efficient than the systems they replace.