Maintaining a comfortable, energy-efficient environment is essential for any commercial space.

When your commercial heating or cooling system begins to short-cycle, it can lead to uncomfortable indoor conditions, increase energy bills and even cause premature equipment failure.

What Is Short Cycling?

Short cycling occurs when an HVAC system switches on and off in fast succession without reaching the desired temperature or completing its full heating or cooling cycle. Instead of running long enough at properly spaced intervals to maintain stable temperatures, the system shuts off after a brief period and then restarts shortly afterward. This can happen with both heating and cooling cycles, making it a year-round issue in commercial buildings with improperly sized units, thermostat problems or other maintenance issues.

In commercial settings, where HVAC systems often need to control temperatures over large areas or multiple zones, short cycling is particularly problematic. Not only does the system fail to adequately heat or cool the space, but it also puts a strain on HVAC components, potentially leading to costly repairs or replacements.

Causes of Short Cycling in Commercial HVAC Units

Several common issues can lead to short cycling in commercial HVAC systems. Identifying the root cause can help prevent further damage and ensure efficient operation.

Oversized or Undersized HVAC Unit

One of the primary causes of short cycling is an improperly sized HVAC system. When an HVAC system is too large for the space, it cools or heats the area very quickly. This rapid cycling leads to uneven temperature distribution and inadequate dehumidification (in cooling mode). The thermostat detects the temperature fluctuations and signals the unit to turn back on after a short interval.

Conversely, an undersized unit will also short cycle, as it cannot adequately handle the load and continuously restarts as it struggles to reach and maintain the desired temperature. For commercial spaces, accurate load calculations are necessary to determine the right system size.

Faulty or Improperly Located Thermostat

The thermostat plays a critical role in temperature regulation, but issues with the thermostat can easily lead to short cycling. If the thermostat is faulty, improperly calibrated or located in an area with temperature fluctuations (such as near a drafty door or window), it may send incorrect signals to the HVAC system.

In a commercial setting, where consistent temperature regulation is essential, incorrect thermostat readings can create significant discomfort and inefficiency.

Dirty or Clogged Air Filters

Air filters are designed to trap dust, debris and other airborne particles, but if they’re not cleaned or replaced regularly, they can restrict airflow. When airflow is limited, the HVAC system has to work harder to push air through, leading to overheating and shutdown.

This cycle of overheating and restarting can cause short cycling, increased energy consumption and decreased indoor air quality.

Low Refrigerant Levels

The compressor can overheat in commercial air conditioners with low refrigerant levels, leading to short cycling. This is often due to a leak, which means that not only does the system lose refrigerant, but it also fails to cool the air effectively.

Low refrigerant levels are a serious issue that can damage the compressor, so it’s crucial to have any leaks addressed by a licensed HVAC technician.

Blocked or Leaky Air Ducts

In a commercial space, blocked or damaged air ducts can significantly affect airflow, leading to imbalances and short cycling. Ductwork obstructions or leaks force the system to compensate, creating pressure imbalances that can lead to overheating. Damaged or leaky ductwork should be repaired quickly and vents and registers should be free of obstructions to prevent airflow issues that can lead to short cycling.

The Impact of Short Cycling on Your HVAC System

• Increased Energy Costs: Each time the HVAC unit powers on, it draws a large amount of energy. Frequent cycling results in higher energy usage and increased utility bills, which can be costly for commercial properties.
  
  
• Wear and Tear on Components: Frequent on-and-off cycling places significant stress on key components like the compressor, fan motor and electrical controls. This wear and tear can lead to costly repairs and ultimately reduce the lifespan of your HVAC system.
  
  
• Reduced Comfort and Air Quality: Short cycling doesn’t allow the system to maintain consistent indoor temperatures, which can create uncomfortable conditions for employees, clients and tenants. It also prevents the system from dehumidifying the air effectively, which can lead to higher humidity levels and diminished indoor air quality.

Solutions to Address and Prevent Short Cycling

Schedule Routine Maintenance

Regular maintenance is key to preventing issues that lead to short cycling. A maintenance check can catch issues like clogged filters, low refrigerant levels and faulty thermostats before they escalate. In commercial settings, routine maintenance is especially crucial due to the higher operational demands placed on the HVAC system.

Proper System Sizing

If your system is oversized or undersized, upgrading to a properly sized unit may be necessary to avoid short cycling. A qualified HVAC contractor can perform a load calculation to determine the correct unit size for your commercial space, ensuring the system you install can operate efficiently.

Replace or Clean Air Filters

Regularly replacing or cleaning air filters can prevent airflow restrictions and keep the system from overheating. For commercial spaces with high usage, air filters should be checked more frequently to prevent clogs.

Inspect and Repair Ductwork

Ductwork issues can easily lead to short cycling, as restricted or leaky ducts put a strain on the system. During regularly scheduled inspections, a commercial HVAC technician can check vents to ensure they are clear and inspect ducts for leaks that might be compromising proper air distribution and balanced flow.

Upgrade Your Thermostat

If thermostat issues are causing short cycling, consider upgrading to a programmable or smart thermostat. These thermostats offer greater precision and can help reduce unnecessary cycling by allowing better control over temperature settings.

Commercial HVAC System Maintenance in Arlington, TX

If your commercial HVAC system is short cycling, or if you’re looking to prevent HVAC issues caused by inadequate maintenance or improper system installation, our team at Tom's Commercial is here for your Tarrant County business.

Contact us today at (817) 857-7400 to schedule a maintenance check and learn more about our commercial HVAC solutions.