What is the difference between a 1 stage and a 2 stage AC Unit?

You’ve probably heard a lot of strange terms when looking for a new air conditioning system, including “1-stage” and “2-stage” AC units. Don’t have any clue what those mean? Don’t fret – we’re here to shed some light on these two types of AC units and what makes each one different from the other.

Compressor Differences

The differences between a 1-stage and 2-stage AC unit come down to the type of compressor each unit uses. The compressor is a key piece of equipment that helps circulate the refrigerant through the AC unit while it’s under pressure. When the experts talk about “stages,” they’re usually referring to the different levels of operation.

Here’s the basic difference between 1-stage and 2-stage AC unit:

• A typical 1-stage AC unit’s compressor operates at 100 percent or it doesn’t operate at all. Regardless of how much cooling your home needs, the compressor will always run at its maximum duty cycle.
• A 2-stage AC unit’s compressor has a “high” and “low” stage. At its high stage, the compressor runs at 100 percent of its duty cycle. At its low stage, when cooling demands are significantly lower but still present, the compressor can step down to 75 percent of its duty cycle or lower.

These differences yield various benefits for both types of AC units, as we’ll go further into detail below.

1-Stage AC Unit Benefits

The main benefit of a 1-stage AC unit is cost. These units are typically cheaper than 2-stage AC units, which could cost hundreds of dollars more. That makes a 1-stage AC unit a bargain option for homeowners who can live without the efficiency and precise cooling that a 2-stage AC unit offers.

2-Stage AC Unit Benefits

A 2-stage AC unit offers a multitude of benefits over a typical 1-stage unit. For starters, you’ll have a more efficient system that uses less energy than its 1-stage counterpart. This can be a boon for homeowners looking to reduce their energy bills any way they can, in spite of the steeper upfront cost.

A 2-stage AC unit also offers more gradual cooling and moisture control when operating at its reduced duty cycle. Running at a reduced rate also means less starting and stopping, which translates into less wear and tear on the compressor itself.

What Are Variable Speed AC Units?

If you’ve heard about 1-stage and 2-stage AC units, then you’ve probably heard about variable speed AC units. Again, the crucial difference between the former two and the latter is how the compressor runs.

With a variable speed AC unit, the compressor operates at a much wider range of capacities. The compressor can run at 10 percent or it can run well above 100 percent, depending on your home’s cooling needs. In short, variable speed AC units are significantly more versatile when it comes to residential climate control.