The Consequences of a Short-Cycling Air Conditioner

Your home’s air conditioner, stationed just outside the house, should stay out of sight and out of mind. You set your thermostat to “cool,” sit back, and enjoy—such are the conveniences of modern living. But if you end up completely forgetting about the air conditioner, you may not notice that something is amiss until it’s too late.

Ordinarily, an air conditioner should run in cycles. To achieve the ideal temperature as dictated by your thermostat, an air conditioner will typically run two or three 15-to-20-minute cooling cycles per hour. This maintains the ideal temperature while giving the air conditioning unit time to rest. If you think the unit operates almost constantly and doesn’t get enough rest, you’re probably right. Complications within an AC unit or the HVAC system can cause what is known as short-cycling: a long series of interrupted cooling cycles in which the air conditioner starts up, shuts down without completing its cycle, and starts back up again. A short-cycling air conditioner can go through a dozen cycles per hour and never fully cool the house—though your electric bill would lead you to believe otherwise. Before we consider the consequences of a short-cycling air conditioner, let’s look at why it happens.

What Causes an Air Conditioner to Short-Cycle?

Short-cycling isn’t the result of one particular process. Rather, it’s a common symptom with several potential root causes. Read about these causes ahead:

A House/Unit Mismatch

The rise of “McMansion” construction in the 21st century has convinced homeowners that bigger is always better and too much is never enough. Even in houses without sprawling square footage, homeowners feel inclined to replace their old air conditioners with larger and more powerful units. However, an imbalance between the strength of an AC unit and the volume of a house can pile onto the upfront costs of the new air conditioner. The powerful air conditioner will quickly cool the air closest to the thermostat, which gives the system the false impression that the entire house has reached the ideal temperature. This leads to the unit shutting off soon after starting up. The air conditioner fails to cool the entire home and spends a great deal of power turning itself on and off.

Air Filters in Need of Replacement

When your household air filters do their job right, they capture harmful particles from the air, such as dust, dirt, mold spores, pollen grains, and carpet fibers. After a filter reaches capacity, however, it transforms from asset to liability, blocking airflow as air struggles to pass through the filter and the particles on it. When airflow meets this resistance in the system, your air conditioner feels it, and it works harder to overcome that resistance. This often leads to the unit attempting to run more cycles, which puts great strain on its components, particularly the compressor. To avoid this, remember to change your filters every 30 to 90 days, depending on the model.

Refrigerant Leak

Think of the refrigerant in your air conditioner as the oil in your car—it’s not the fuel, but a necessary fluid that circulates throughout the unit to keep it working. When you have an oil leak, your car suffers. When you have a refrigerant leak, your air conditioner suffers. Because refrigerants shift from liquid to gas, a leak can prove visually undetectable as the fluid leaks in the gaseous phase. A lack of refrigerant can overwork the air conditioner and make it run in quick bursts.

What Does Short-Cycling Do?

What ramifications does short-cycling have on your home’s air quality and the condition of your air conditioner? Is this something you and the unit can live with?

Wear, Tear, and Repair

Let’s once again compare your air conditioner to your car. Putting moving parts back into motion expends a lot of energy. Whether you’re starting a car or an air conditioner, you’re overcoming inertia. To do so time after time over the course of each day causes premature wear and tear, particularly on the air conditioner’s compressor, one of the most important components of a unit. Wearing out a compressor can cause it to overheat, and sustained overheating can lead to the compressor suffering a premature and costly demise. You’ll face high costs to replace a compressor, and it’s not worth the trouble—HVAC technicians are likely to tell you that you’re better off replacing the entire air conditioner with a more energy-efficient and ozone-friendly model. While this can be a welcome opportunity for environmental progress, it can also prove troublesome if you haven’t budgeted for a new unit.

Hot Here, Cool There

When an air conditioner can’t run its regularly scheduled cycles, you’ll feel it in your house. A short-cycling air conditioner’s bursts of cool air are inconsistent, and as a result, temperatures around the house are inconsistent, too. If your thermostat is in your living room, you may find that your living room is at a brisk 65 degrees while bedrooms remain at a balmy 74. This is because they don’t receive enough air, meaning the unit cools the central location but fails to circulate to auxiliary areas. This discomfort can become a serious problem as the dog days of summer set in. An air conditioner that fails to remove warm air from the home also fails to remove humidity. Sustained levels of high humidity in the home can cause furniture and paint to release volatile organic compounds, or VOCs, in a process known as “off-gassing.” Inhalation of these chemicals can lead to both adverse short-term and long-term health effects.

High Electric Bills

Repairing or replacing a failing air conditioner isn’t the only costly consequence of a short-cycling air conditioner. The energy that the unit uses to start itself up several times an hour will drive up your electricity usage, with little to show for it in terms of comfort. As troublesome as wasteful furnace usage can be in the winter, remember that in almost all locations, electricity is more expensive than natural gas, and these cost overruns can quickly become significant.

What You Can Do

Preventing a short-cycling AC unit is important. If you can resolve this issue without the intervention of an experienced technician, you’re in luck. Fortunately, a new filter may be all it takes to resume normal cycling. Our AAF Flanders EZ Flow air filters keep air clean and pressure low, which could keep cycles at their normal length.

The Consequences of a Short-Cycling Air Conditioner

EducationHome maintenanceTips and tricks

Leave a comment

All comments are moderated before being published