How to Clean Commercial HVAC Coils

Dirty HVAC coils can significantly reduce system efficiency, sometimes increasing energy consumption by as much as 30%. That’s why it’s crucial to implement a regular coil-cleaning schedule, especially after installing new equipment. Just like a visit to the dentist, coil cleaning might not be something you look forward to—but it’s definitely necessary.

HOW DO I KNOW IF MY COILS ARE DIRTY?

While a scheduled maintenance plan is the best way to keep your coils in top shape, there are some signs that indicate when a cleaning is needed.

• Check the air pressure drop across the coil against the design specifications. If the pressure is higher than normal, it could mean the coil is dirty.
• For condenser coils, high refrigerant head pressure may signal dirt buildup. For DX evaporator coils, low suction pressure and poor airflow are common indicators.
• Visually inspect the coils. If they look grimy or clogged, it's time for a cleaning.

HOW OFTEN SHOULD COILS BE CLEANED?

Under normal conditions, commercial HVAC coils should be cleaned at least once a year. However, certain environments require more frequent attention:

• Condenser coils under extreme conditions: Clean quarterly.
• Units near saltwater (within one mile): Clean monthly.
• DX evaporator coils in corrosive environments: Clean quarterly.
• High fin density coils: Clean more frequently due to increased dirt accumulation.

HOW TO CLEAN A COIL:

Before starting, always disconnect and lock out the electrical power to avoid accidental activation. Avoid getting water into motors or electrical components to prevent damage.

Start by removing large debris and straightening any bent fins. Use a pressure washer with a 25–40 degree nozzle to clean the coil without damaging the delicate aluminum fins. Apply a non-acidic, alkaline-based cleaner such as Nu-Brite for condensers and Evap Pow’r-C for evaporators. These cleaners help lift dirt from deep within the coil.

If an acidic cleaner is required, follow the instructions carefully. Any leftover residue can damage the coil. Only use a soft-bristle brush for gentle scrubbing if needed. After cleaning, rinse thoroughly with a power washer or hose.

Always follow the manufacturer’s guidelines when using cleaning products. Using harsh or toxic chemicals improperly can cause serious harm to both people and equipment.

USE STEAM TO REDUCE MESS

For interior coils, steam cleaning is a great alternative. It’s effective and reduces water mess. Just be careful not to over-saturate the motor or electrical parts. Use low pressure and keep the steam parallel to the fins to avoid bending them.

A LITTLE MAINTENANCE GOES A LONG WAY

Properly maintained commercial HVAC coils can last many years. Condenser coils typically last 10–15 years, while DX evaporator coils can last 15–20 years. Water coils often last over 20 years. Even quality replacement coils can match or exceed OEM performance, especially if made with thicker materials.

However, environmental factors—like proximity to saltwater or corrosive substances—can shorten the life of your coils. So regular inspections and cleanings are key to long-term performance.

WHAT IF MY COIL IS COATED?

Coated coils offer extra protection against corrosion, but they still need regular cleaning. The coating can get dirty just like any other coil, so maintenance is just as important. Keeping the coil clean ensures the coating remains effective and lasts longer.

Have questions or need a quote? Feel free to reach out anytime. Proper care of your HVAC system can save you time, money, and headaches in the long run.