While standard air conditioners can only turn either completely on or off, a variable-speed air conditioner can run at different speeds depending on the cooling needs of your home.
This makes variable-speed air conditioners much more energy efficient.
How? Well, imagine driving your car with just an on/off switch. A red light turns green and you have to floor it until the next red light appears and you slam on your breaks. Not very efficient.
That method is how old, fixed-speed air conditioners work. They are either on or off, which causes them to cycle on and off quite frequently, wasting energy.
Variable-speed air conditioners work more like the gas pedal in your car, letting the AC adjust to the needs of your home. This way the AC can run at a low setting most of the summer, saving you serious money.
The heart of an air conditioner is the compressor. New variable-speed air conditioners have compressors that can run at different speeds to cool your home at different rates.
A diagram of the main parts of an AC system. Image source.
The compressor is responsible for pumping refrigerant to and from your indoor unit’s coils.
So when it’s extremely hot outside and you’ve cranked your thermostat way down, the compressor will speed up and pump cool refrigerant to your home’s air handler more quickly. Your blower will also run at a higher speed. These 2 things combined cool your home more quickly.
But when the weather is more mild, the compressor slows down and cools your home more slowly. The AC runs for longer periods, but at a lower, more efficient setting.
Because a variable-speed AC runs longer, it saves you money in 2 ways:
Fewer on/off cycles
An air conditioner uses a spike of energy to start up each time. So the fewer times the AC turns on, the more it saves.
This is similar to how your car gets better MPG on the highway than in the city because there is less stopping and starting.
Uses a lower setting when it does run
When the air conditioner does run, it’s usually at a lower, more energy efficient setting. Think of it like needing to travel a mile by foot. You could try sprinting the entire mile. That would get you there the quickest. But it’d also use the most energy.
If you wanted to conserve energy and weren’t concerned about time, you’d walk.
That’s how your air conditioner is saving you energy costs. Where a traditional air conditioner will sprint for short periods of time and then stop, a variable-speed AC can adjust its speed. It will walk most often and then only occasionally jog when temperatures rise, very rarely needing to sprint.
But energy savings isn’t the only reason to get a variable-speed air conditioner…
More even temperatures in your home
The longer runtime of variable-speed air conditioners helps distribute the cool air more evenly throughout your home. That means fewer hot and cold spots.
Since it runs at lower speeds, it's also much quieter. You may hardly know the variable-speed air conditioner is there.
Removes more humidity
Since variable-speed air conditioners run longer at slower speeds, they remove more humidity than their standard counterparts.
That level of humidity control is be especially comforting during Atlanta’s muggy summers.
Coolray is your Atlanta-area home comfort expert with specialists in heating, air conditioning, air quality and plumbing.