A commercial cooling system is somewhat different than a residential system.  It is complex, with problems occurring even if proper maintenance is done.  It is the second most popular (the first being roofs) component in a commercial inspection that may prove costly to repair or replace.  Here are the most common problems in commercial air conditioning systems.


Poor Air Quality

Air quality can be affected by many factors. These can be as simple as a dirty air filter, or as serious as a gas leak. The culprit behind odors emanating from your HVAC ducts can be dirty air filters, condensed stagnant water, debris melting on the heat exchanger, or overheating parts. Filters should be changed out monthly.

air quality

Inconsistent heating and/or cooling

If visitors and employees are complaining about being too cold or too hot in different areas of the building, something might be wrong with your ductwork. These airflow inconsistencies could mean that the ductwork is cracked or leaking.  This would entail finding and fixing the source of the leak. It could also be a faulty thermostat, which is a simple enough fix.

Ventilation issues

If you experience an overheating air conditioning unit frequently, maybe something is blocking some vents, prompting the unit to work harder.

dirty vents

Rooftop unit is damaged

These are the big boxes on the commercial building roofs. Since they are constantly exposed to the elements and debris such as leaves, pieces of trash, plastic and paper may have gotten inside the boxes. If left unchecked, it would eventually hamper the normal operation of the unit.

Sounds strange

If there are strange sounds coming from the unit—whether indoor or outdoor—it is a clear indication of something wrong with the unit. Modern air conditioning systems have been designed to be as quiet as possible to provide cooling comfort without distraction, so it’s safe to say that something is either loose or broken inside the unit.

damaged hvac

Drain lines are clogged

As the air-conditioning unit is doing its job cooling the air, moisture and condensation forms and this needs to go somewhere, which is the only purpose of the drain line.  The drain line routes excess water and condensation away from the HVAC unit.  As they are exposed to moisture, drain lines tend to get clogged from time to time. Typically, dirt is the culprit, and if left unchecked for some time, this could cause algae to grow within the drain lines. When this occurs, water can back up into the drain pan, causing it to leak out and cause water damage. Periodic checks and cleaning of the drain line should prevent any water from backing up and causing problems.

clogged drain

Dirty or clogged filters

Dirty and worn filters can force your air conditioning unit to work harder, which increases energy costs and reduces the life of your system. Frequent monitoring and quarterly replacement of your filters will ensure optimal HVAC system performance. It will also improve the indoor air quality of your building by keeping dust, allergens, and other air pollutants at bay.


Sudden stop

There is no reason for your air conditioning unit to stop working unexpectedly. If it does, it could only mean that it has overheated or there is another problem. Fuses work by protecting sensitive electrical components from overheating, and can be found in the evaporator coil. When your HVAC unit shuts off unexpectedly, the circuit breaker is the first place you should look for any issues.  It’s a simple matter of replacing a blown fuse, but this should only be left to the professionals.

Burned capacitors

Even in well-maintained air conditioning systems, some parts might experience wear and tear issues way ahead of the rest of the system. There are two capacitors in an HVAC unit: start and run. If either of the capacitors burn out, the unit will not start or run properly, and will need to be replaced.


Leaking refrigerant

Refrigerants are liquid agents that make air conditioning possible. Contained within the coils of an HVAC system, refrigerants cool and dehumidify indoor air. When your unit doesn’t have enough refrigerant, it can’t do its job and the air it produces is not very cold. This issue not only leaves the inside of your building too hot but it also causes the condenser to work overtime, leading to additional – and more expensive – system problems.


System Capacity

If your visitors or employees are complaining that it’s too hot in the building, it could mean that your system is too small for your building. This could be a costly mistake, as another unit (a bigger one) may be needed to address the problem.

Lack of Maintenance

Just like cars, HVAC systems require regular maintenance. Maintenance contracts can prevent costly repairs, by detecting small problems before they become big problems. Many HVAC issues stem from negligence, and can be prevented with routine maintenance inspections.

Thermostat malfunctions

When problems arise, it’s easy to assume the issue is with your actual HVAC system. You may be surprised to learn that it’s just as likely to be a problem with your thermostat instead. Your thermostat regulates the timing and amount of hot or cold air your unit should produce. So when your thermostat is malfunctioning, your building can suffer from intermittent temperature fluctuations.

By understanding where problems might originate in your HVAC system, you can take proactive measures to ensure it is in optimal working condition and avoid major problems before they occur. Being preemptive about your system’s needs can maximize efficiency, control unnecessary energy consumption and expenses.


How much does it cost to replace a commercial cooling system?

Small businesses with one cooling zone can expect to pay $3 to $4 per square foot for their unit, but this can range from $9.50 to $12.00 for larger businesses. However, this can vary depending on the size of your business and what brand you purchase, which means your price could hit five figures or more. Given the number of variables that affect the price, your costs could be much higher or lower depending on your needs.