What Are the Advantages of a Two-Stage Cooling AC Unit?

Air conditioners work by introducing cooled air and reducing humidity.

Power

Air conditioners reduce indoor temperatures for added comfortAir conditioners reduce indoor temperatures for added comfort
Conventional one-stage cooling units work by coming on whenever the temperature falls below the user set temperature and then back off again when the desired temperature is met. This cycle of on and off can be inefficient. Two-stage air conditioning reduces inefficiency because it has a multi-speed fan and compressor. Two-stage air conditioning has many advantages.

Two-stage cooling AC units operate at two separate power levels or speeds -- 67 percent or 100 percent. Which speed it operates on depends on the current temperature as compared to the temperature you would like it at. When the ambient temperature is only a few degrees from the temperature desired, the unit will kick on at 67 percent and stay on to maintain the temperature. It runs at 100 percent when the ambient temperature is far from the desired temperature. Because two-stage units do not go through the typical on-off cycle that one-stage units go through, energy efficiency is increased since energy is wasted in starting up.

Time Running

Two-stage cooling AC units are on or running more often than conventional air conditioners. Because two-stage units keep a steady continuous stream of cooled air pumping, they are on longer but since most often this is at a lower capacity, less power is used.

Humidity

Two-stage cooling units produce less humidity than one stage. This is because in the second stage, as the cooled air passes through a water-soaked pad, it picks up less water as cool air cannot hold as much moisture as warm air. The resulting air has between 50 and 70 percent humidity which is less than the 80 percent of a conventional one stage system.

Cost

Because two stage cooling units operate at a lower capacity the majority of the time, the operating cost is lower than conventional systems. Energy costs for operating a two-stage system are 60 to 75 percent lower than conventional cooling systems, although energy use varies by climate.

About the Author

Houston-based Zoha Natiq holds her Master of Education in counseling and works at a large local college, assisting students with their career goals. She has been writing for more than 10 years, both fiction and nonfiction, utilizing her knowledge of human behavior and the psyche.