While improved energy costs may be enough to convince homeowners of its benefits, the two-stage cooling system delivers additional perks, like these:
Improved humidity control. When the A/C runs continuously, it can dehumidify the air better. Short but strong blasts of air don't provide enough time for the A/C to remove water vapor from the air inside your home, but a continuous operation gives the coils sufficient time to draw water vapor into the system and evaporate.
Comfort. The on-off cycling often leads to drastically differing temperatures in the home, depending on whether the system is running or off. Typically, when the A/C starts up, it delivers a strong blast of chilly air, often making home occupants very cold. But as soon as the system shuts down, and there's no air movement in the home, the home quickly becomes hot and stuffy. Operating in continuous mode helps the two-stage system bypass this problem, circulating just enough air in the home to make it comfortable, with little variation in temperature.
Longer service life. A compressor that shuts on and off a lot is subject to increased wear and tear, and will eventually wear out and then break down. With less on-off cycling, the two-stage compressor lasts longer, especially if you schedule annual preventive maintenance for your cooling system.
Improved Winter Comfort. As a result of using the variable speed indoor unit, you get the ability to "throttle" heat delivery. Lower heat output at a slower speed increases comfort, saves fuel and doesn't over dry the indoor air. Full heat output is delivered as needed based on thermostat demand and user settings.
With so much at stake when it comes to home cooling, take the time to consider your options when you're facing an air conditioner replacement. Two-stage systems cost more initially but deliver significant perks on the back end for homeowners who invest in them.