Outdoor HVAC units

How it Works: Two-Stage Heating and Cooling

The name “two-stage” refers to the method used for heating or cooling the air inside your house. This method is considered a midrange investment that improves efficiency and comfort inside your home. Advanced humidity control is another perk of this system and an important aspect because more moisture is removed, lowering the risk of mold and increasing indoor air quality.

If you wonder if this system suits your home, you have come to the right place! In this blog, our experts explain what two-stage heating and cooling are and why they could benefit you.

How Does This System Work?

It is almost like you have two different compressors outside your house because this system allows the compressor to work at two capacities. One capacity will be more aggressive and used during the summer, while the other will perform at 65-70% capacity when the weather is not scorching hot.

When the system runs at a lower capacity, it tends to operate longer than a unit that runs at 100% capacity. This variation in power is good because it allows for more consistent temperatures, increased humidity control, and cleaner air because more air is passing through the filters.


Single-stage compressors only work at full blast, which increases your energy bill. You will pay more because the unit will run full blast, even if you need the house to cool a degree or two.

Two-stage systems are more efficient because they run longer at a lower speed. Compare this to a car. If you are constantly stopping your vehicle, then speeding away, your gas will decrease more rapidly than if you were cruising at a constant speed of about 55-70 MPH.

SEER Rating

SEER stands for seasonal energy efficiency ratio and is a rating given to HVAC units to indicate their efficiency. The higher the number, the better efficiency. A rating between 13 and 18 is considered to be very good. Two-stage cooling systems are rated between 16 and 19, while single-stage units rate between 13 and 16. Remember, the higher the rating, the better the efficiency.

We Can Help!

At Scott Harrison Plumbing and Heating, Inc., we take pride in the quality of our work because we care deeply about taking care of your home and family. Each of our fully licensed and insured technicians is equipped with the experience to assist you with your home’s heating and cooling system and help you make the right choice for you! For more information, give us a call today. (714) 695-5566