The Truth About Variable Capacity Air Conditioning

Open air conditioning unit

Choosing The Right HVAC System Is Your Solution To Consistent Comfort!

Think about how much time you spend in your Scottsdale, Arizona home. According to the U.S. Environmental Protection Agency (EPA), people in the United States spend about 69% of their time indoors at home. Now ask yourself: In that time spent at home, are you comfortable?

If your answer is no, think about what is causing you to be uncomfortable. Is it the temperature? Poor air circulation? Humid/stuffy rooms? There are several factors that affect your overall comfort.

Common Comfort Concerns:

  • Do you have trouble sleeping in the summer?
  • Do you notice hot and/or cold spots throughout your home?
  • Do you feel temperature swings between cycles?

If you struggle with any of the above comfort concerns, you should know that there are SOLUTIONS! HVAC systems allow you to control your indoor comfort, ensuring your time spent at home is utmost enjoyable. The key is knowing which is the right system to fulfill your needs, because different air conditioners provide different benefits.

What are the three types of air conditioning systems?

  1. Single-Stage
  2. Two-Stage
  3. Variable Capacity


As it’s name suggests, single-stage air conditioning systems have only one level of operation, or a single stage of cooling output. These systems are either on and running at 100% capacity or off completely. Also known as fixed-capacity systems, these units run on high speed even if only a small amount of heating or cooling is needed. This often equates to a significant amount of wasted energy and money. Single-stage systems are the most common type of air conditioners installed in Arizona.


On the other hand, two-stage air conditioning systems have two levels of output – high speed for our hot Scottsdale summer days and low speed for milder temperatures. This is a perfect design for the Scottsdale, AZ climate. On the low setting, two-stage systems run for longer periods of time which provides more even cooling and better humidity control. By running for longer periods of time, these systems turn on and off less often which reduces wear and tear on the compressor


Variable-capacity air conditioning and heat pump systems are controlled differently than single and two-stage systems. Instead of cycling on at full capacity and cycling off when the thermostat reaches its designated temperature, these units operate according to the heating and cooling load conditions of the home. The heating or cooling “load” refers to the amount of heat energy that would need to be added or removed from a space to maintain its desired comfort level.

The efficiency of an air conditioner is directly related to the type of compressor and circuit control drive it uses. It is often said that the compressor is the heart of the system; they are vital in ensuring that the entire system runs smoothly and efficiently. Variable-capacity systems are unique in that they use variable-speed compressors which modulate in increments of 1% and fractions of a percent.

Variable-capacity air conditioning systems are definitely the wave of the future. They will become the standard, eventually replacing single-stage system all together.

Richard Staiano, CEO and President of National Compressor Exchange, Inc., said variable-speed compressors offer cost savings both in their energy usage and longevity compared to traditional equipment. “When it comes to variable speed, there’s not much to decide… If customers are educated and decide to make the investment, they’ll find that, in the long run, they’ll save on overall life cycle costs. They’ll save energy from day one, and the equipment will last longer because, when it’s running, it’s not always running at full speed.”

You can compare a single-stage system to a light switch – it’s either on or off. While a two-stage system is more like a fan switch – it can be on low or high speed. A variable-capacity system has multiple speeds and can adjust according to your home’s specific requirements. Adaptable capacity = higher efficiency.

Benefits of Variable-Capacity Systems

  • Reduced humidity
  • Quiet operation
  • Reduced temperature fluctuations
  • Improved air quality
  • Prolong the life of your HVAC system
  • Increased comfort
  • Energy efficiency

Heating, Ventilation, and Air Conditioning (HVAC) is an ever-evolving industry that regularly experiences changes in technology. It is important to stay up-to-date with the advancements in equipment and to take advantage of these upgrades to live more comfortably and efficiently.

The Lennox XC25 Variable Speed Air Conditioner

Purchasing a new air conditioner is an investment in your home and your comfort. Choosing the right system is your solution to consistent comfort!

The Lennox XC25 Variable Speed Air Conditioner

  • Silent comfort technology – 50% quieter than a standard air conditioner
  • Industry leading efficiencies of up to 26 SEER
  • Reduce heating and cooling costs by up to 50%
The Trane XV201 Variable Speed air conditioner

The Trane XV20i Variable Speed Air Conditioner

  • Ratings up to 22 SEER
  • TruComfort technology allows cooling capacity to increase in as little as 1/10 of 1% increments
  • Save an estimated 64% in energy costs with this unit

Contact Us

  • This field is for validation purposes and should be left unchanged.