Introduction
When a commercial HVAC unit is working properly for years, it won’t suddenly shutoff or fail. Before any failures, the system shows signs that no one should ignore.
You might notice changes in temperature, airflows, and energy bills. When these components fail to deliver the top notch performance, know that system performance has reduced.
Since these changes can point to a commercial HVAC system losing efficiency, the reason is not only HVAC unit.
What Does Declining Commercial HVAC Performance Look Like?
Before troubleshooting, diagnose the problem. Some signs are listed below:
- Rooms taking longer to reach the desired temperature
- Uneven temperatures across the building
- HVAC equipment running for unusually long periods
- Weak airflow from supply vents
- Increasing energy consumption
- Frequent cycling
- Unusual sounds or odors
- More frequent service calls
- Recurring comfort complaints
10 Commercial HVAC Troubleshooting Tips
1. Start With Operating History
Don’t begin by replacing components. Note out the operating patterns of the system.
Review:
- Previous maintenance reports
- Repair history
- Energy bills
- Occupancy changes
- Temperature complaints
- Equipment runtime
- Previous fault codes
- Recent changes to building operations
2. Check Filters and Airflow
Airflow must be considered as a priority when conducting commercial HVAC troubleshooting.
Check for:
- Dirty or overloaded filters
- Blocked return-air openings
- Dirty blower wheels
- Loose or damaged belts
- Unusual static pressure
- Restricted ductwork
- Poor airflow
3. Inspect the Coils
Coils usually transfer the heat.
During inspection, look for:
- Dust and dirt on the surface
- Grease or debris
- Damaged fins
- Corrosion
- Restricted airflow
- Patches of moisture or contamination
4. Investigate Refrigerant Performance
The cooling capacity and efficiency of an HVAC unit can be affected by refrigerant leaks or incorrect charge.
It is not advised to add on refrigerant without professional consultation.
A qualified technician should evaluate:
- Pressures
- Temperature controls
- Possible leaks
- Evaporator performance
- Condenser performance
- Compressor operation
5. Check Controls and Sensors
Sometimes the equipment is capable of performing properly, but the controls are telling it to operate incorrectly.
Inspect:
- Thermostats
- Temperature sensors
- Scheduling
- Setpoints
- Economizer operation
- Dampers
- Actuators
- Building automation system alarms
A faulty sensor can cause unnecessary heating or cooling even when the mechanical equipment itself is functioning normally.
The Department of Energy notes that properly calibrated control systems are important for commercial HVAC efficiency and can help identify equipment faults.
6. Don’t Forget the Ductwork
An HVAC unit can operate correctly while the building still experiences poor comfort.
Why?
The problem may be somewhere between the equipment and occupied space.
Look for:
- Leaking ducts
- Damaged insulation
- Loose connections
- Poor balancing
- Restricted sections
- Incorrect dampers
- Unusual pressure differences
7. Examine Electrical and Mechanical Components
Aging components can gradually affect commercial HVAC performance before they fail completely.
Depending on the equipment, a technician may inspect:
- Motors
- Capacitors
- Electrical connections
- Bearings
- Belts
- Contactors
- Fans
- Compressors
- Pumps
8. Compare Current Performance With Baseline Data
One of the best ways to understand why is my commercial HVAC system losing efficiency is to compare current operating data with previous results.
Track useful information such as:
- Energy consumption
- Supply-air temperature
- Return-air temperature
- Airflow
- Static pressure
- Runtime
- Refrigerant-related readings
- Temperature complaints
9. Review the Building, Not Just the HVAC Equipment
Changes in the building can increase HVAC demand.
For example:
- Occupancy may have increased.
- Operating hours may have changed.
- New equipment may produce additional heat.
- Interior spaces may have been remodeled.
- Ventilation requirements may have changed.
- Doors or windows may be opened more frequently.
So the investigation should consider the entire building environment.
What Should You Do If the System Is Still Underperforming?
Conducting the basic commercial HVAC maintenance may not restore its performance. In such scenario, seek professional help from Morgan Mechanicals.
A useful report should identify:
- The observed problem
- Likely cause
- Measurements taken
- Components tested
- Recommended repair
- Repair priority
- Expected impact
- Whether further monitoring is needed
This makes it easier to separate a simple maintenance issue from a larger equipment problem.
How Commercial HVAC Maintenance Prevents Performance Loss
Regular commercial HVAC maintenance is more than changing filters and performing an annual tune-up.
A proactive program should include:
- Filter and airflow checks
- Coil inspections
- Electrical inspections
- Controls testing
- Condensate drain checks
- Mechanical component inspections
- Refrigerant-system evaluation
- Ductwork assessment
- Performance tracking
Conclusion
When a commercial HVAC system is losing efficiency, do not assume instantly that any component might require replacement. Instead, consider the warning signs.
Check airflow, coils, controls, refrigerant performance, ductwork, mechanical components, and changes in building use. Then compare current performance with historical data.
A systematic investigation and accurate troubleshooting by professionals will reveal the real cause and lead to relevant solution.