Variable Capacity Central Air Conditioning Explained

February 15, 2023
HVAC Lifespan in Olathe, KS

When it comes to central air conditioners, there are several different technologies available that affect more than just the installation cost. Rather, these differences affect everything from the system’s efficiency and operating costs to your home’s comfort. Discover the differences between single-stage, two-stage, and variable-capacity air conditioners and why more homeowners are choosing variable-capacity systems.

Standard Single-Capacity Systems

A single-capacity system simply means that it’s either on or off. The unit is also running on high whenever it’s on. This consumes the maximum amount of energy during the cooling cycles and also produces the most cool air in your home. Unfortunately, that means when it’s running in moderate weather, it will commonly run shorter cycles, ineffectively circulating the air and leaving your house more humid.

Difference Between Two-Stage and Variable-Capacity Systems

When you get into higher-efficiency air conditioners, you have the option of two-stage and variable-capacity systems. Two-stage systems have a high and a low setting. The unit will run on the low setting about 70% of the operating time. However, that still leaves a wide range in capacity, causing more energy consumption when the system needs a little more capacity than the low setting offers.

Variable-capacity systems can adjust the output in increments as small as 1%, starting at about 35% of the rated capacity. With this degree of capacity modification, the system runs continuously, offering several unique benefits.

Quieter Operation

The noise an air conditioner makes is both outside at the condensing unit and inside with the circulating fan. Along with reduced capacity at the AC compressor, the fans don’t spin as quickly, reducing how much air circulates. This decreases the overall noise both inside and outside, making the system less intrusive for your household and your neighbors.

Better Home Comfort

Keeping your house comfortable encompasses a couple of different aspects. First, it’s achieving the temperature that you find comfortable. Next, it’s getting that temperature consistent throughout your residence. Finally, it’s reducing the humidity level in your house.

Single- and two-stage air conditioners can easily achieve the first aspect. However, it’s difficult to maintain an even temperature or effectively control humidity without constantly circulating air. By simply running at a lower capacity all the time, the variable-capacity system improves how even the temperature is around your home and continually works on controlling your house’s humidity level.

Improved Indoor Air Quality

Improving indoor air quality deals with three aspects: removing airborne contaminants, controlling humidity, and purifying the air. Variable-capacity air conditioners help with the first two of these aspects. The constantly moving air means that you’re moving more air through the air filter, allowing it to remove more contaminants from the air.

As we discussed above, the constantly circulating air allows the system to better control humidity. Beyond making your house more comfortable, this also makes the environment less hospitable for biological contaminant development, such as mold.

Reduced Cooling Bills

At first glance, it doesn’t make sense that a system running constantly will consume less energy than one that cycles on and off. However, let’s explore how these systems use power.

First, an air conditioner consumes the most power when it initially starts up as it works to get the fan motors and compressor going. Therefore, reducing the number of times the unit starts reduces the number of large power draws. Second, the amount of power consumed for more capacity isn’t linear. The higher the capacity rises, the larger the increase in power consumption. When it’s running at a lower capacity, it’s reduced the energy consumption by more than the capacity reduction. The translates into substantially less energy consumed to power your system, especially during moderate temperatures.

Extended Service Life

In addition to consuming more energy, starting a cooling cycle puts the most wear on the system. By reducing the number of times the appliance has to start, you reduce wear on the compressor and capacitor. Further, just like energy consumption, the higher the capacity the system runs, the greater the increased wear on the compressor and other parts becomes. The closer the system runs to the 35% capacity, the exponentially less wear it puts on the equipment, thereby reducing how frequently you’ll need repairs and extending how long the system will serve your home.

Homeowners around Olathe turn to Mike Bryant Heating & Cooling when they want dependable home comfort solutions. Our team takes pride in providing trusted heating and cooling installation, maintenance, and repairs together with indoor air quality and geothermal solutions. Call today to schedule your consultation with one of our expert technicians to discuss whether a variable-speed central air conditioner is right for your home.

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