What is Air Conditioner Staging? And What’s Best for Me?

May 13, 2021
Lennox technician discussing air conditioner with man in yard

Before the warm weather arrives in the Kansas City Metro Area, it is a good idea to check that your cooling system is operating by having maintenance completed. This ensures the system is operating within the manufacturer’s specifications, and the equipment can run the most effectively. If you decide it is time for a new air conditioner, you probably noticed that there are several types on the market. The HVAC industry has made many strides thanks to new technology. These enhancements have drastically affected the SEER Ratings (the efficiency) and the staging (humidity control for comfort). Typically, more stages equal higher efficiency. There are 3 main categories of Air Conditioner staging: Single Stage, Multistage, or Variable Capacity. At Summit Heating and Cooling, we keep up with those trends, specializing in new technologies, and can guide our customers through their various options.


There is sometimes confusion on what the component outside is called. These components are called condensers, and there are 2 main types of condensers: Air Conditioners and Heat Pumps. These units are simply heated rejection machines. An air conditioner absorbs heat from the inside of a home, transfers it through refrigerant, and rejects it outside utilizing the air conditioner. A heat pump does the exact same thing, but it can also reverse the process. Meaning it can absorb heat from outside and bring it into the home.

Most systems that are being replaced today are single-stage. They have been the most common type of AC throughout the years and thus are the most prevalent. These condensers are on-demand units. On-demand means that the thermostat triggers the unit to turn on when the temperature increases above the set temperature and turn off once the air has cooled back to the set temperature. During the operating time of this type of AC, humidity is also removed from the air causing increased comfort in the home.

In many parts of the country, like Kansas City, high humidity levels and wide temperature ranges make it difficult for many homeowners to achieve their desired in-home comfort temperature. While single-stage AC’s have been the industry standard for many years, they have their limitations. Single-stage systems must be sized to operate within a 20-degree temperature spread, but it is difficult to have an AC be a large enough tonnage to support a home on hotter days, like our 97-degree July days, yet small enough to run long enough on an 84-degree day. In the past homeowners and contractors have had to choose between dehumidification and cooling capacity at more extreme heat. Thus, the advent of the staging of HVAC systems.

Multistage Condensers

A multistage air conditioner has multiple compressor speeds instead of one. The most common is a 2-Stage AC, but there is also 5-Stage available. With a 2-stage condenser, there is a medium setting (set to operate at 60-70% of the capacity) and a high stage setting (set to operate at 100% capacity). Sometimes you hear these referred to as a first and second stage. These units are fantastic for situations where your home’s needed capacity is between tonnages or if a home struggles to meet desired temperatures on extremely hot days, but you do not want to sacrifice dehumidification in your home on milder days. The concept is that with staged units the equipment can run longer, especially on milder days, so that the system is removing humidity longer making the home more comfortable. This is also a more efficient way to operate because the most energy of an ac occurs when it starts. Compare this to stopping and starting your car and how much gas that burns. Every time you step on the gas after coming to a complete stop, your car burns extra gas. You might notice that you have to fill up more often when you are in constant stop-and-go traffic. When you can travel at a constant speed, the gas seems to last longer.

Typically, this system can:

  • Dehumidify better
  • Save on energy costs
  • Provide precise temperatures
  • Require fewer repairs

Variable Capacity Equipment

This term may sound intimidating, but you already have one type of variable capacity equipment – your car. The Heating and Cooling system in most cars these days has temperature settings, some you control and others the computer in your car does. Variable-capacity equipment follows the same basic idea. The blower in your furnace, air conditioner, and thermostat communicate to adjust the blower speeds and capacity of the AC based on what you set as your comfort levels in the home and the conditions outside the home. This just means that as it gets hotter or cooler and higher or lower humidity, the system adjusts to make it more comfortable inside your home. Typically, these systems are almost always running, but using very low levels of electricity and are very, very efficient. Because they are running all the time, they can keep humidity levels much closer to desired settings and temperature levels extremely close to set temperatures. Some systems can keep temp within .1 degree of thermostat settings. Most manufacturers have a variable capacity unit, and they range in efficiency from 18 SEER to 28 SEER. To put that in perspective, the minimum efficiency today is 13 SEER, and most systems currently being replaced are between 8 and 10 SEER. Now, not all variable capacity condensers are communicating. When they are communicating, the furnace, AC, and thermostat all “talk” to each other in order to quickly regulate and balance how the system operates. Systems that do not communicate do not have as much control of temperature and humidity because they are dependent on reading temperatures at the condenser. Compare this to texting versus a face-to-face conversation. Condensers do no have to be paired with a specific furnace, but it is not a good idea to pair them with an older furnace that has an old, PSC blower motor. New blower motors are DC-powered and run on 60 watts while old-style blowers run on 600 watts. While older furnaces are capable of being paired with a newer condenser, the older, less efficient PSC blower motor will drastically increase your electric bill which we would not recommend. Hence, variable capacity equipment is the best way to increase your home’s comfort and efficiency.

  • Better dehumidification
  • Best energy efficiency
  • Precise temperatures
  • Least amount of repairs

All big-ticket household appliances require regular maintenance. The variable capacity condenser is no exception. If it is inspected by a professional at least once a year, it is more likely to last through its expected lifespan, which should be longer than most of today’s more standard equipment.

How Do You Pick What’s Best for You and Your Home?

The best way to make a choice is to have one of Summit’s professional in-home comfort consultants come to your home, assess your home, have a conversation about your needs and wants, and get all the options that suit you and your family’s needs. All cooling systems require an upfront investment, but it is always best to have all your options before making decisions that will affect your home’s comfort for 15 to 25 years. To find the air conditioner that best meets your needs, give our team at Summit Heating and Cooling a call today to schedule a consultation.

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