Overview

Maintaining commercial refrigeration efficiency can feel like a guessing game, but one often-overlooked issue can cause bigger problems than expected: dirty coils. In this post, Leading Edge Mechanical Inc’s commercial refrigeration technicians explain five specific ways coil buildup can affect your system's performance, reduce efficiency, affect reliable operation, and how you can avoid it.

Introduction

You probably don’t think about your refrigeration coils until something starts to feel off. Maybe the system sounds louder than usual, or it’s taking longer to cool than it used to. It’s easy to brush off small changes when everything still “works,” but those little changes usually point to much bigger problems. Coil cleaning might not be the first thing on your maintenance list, but it can make all the difference in how your system performs over time.

What Are Coils in a Commercial Refrigeration System?

In a commercial refrigeration system, coils are essential for moving heat in and out of the unit. There are typically two types: evaporator coils and condenser coils.

The evaporator coil absorbs heat from inside the refrigerated space, helping to keep food or products cold. The condenser coil releases that heat outside the unit to complete the cooling cycle. Both coils rely on clear airflow and clean surfaces to function efficiently.

When either coil becomes coated with dirt or debris, the system must work harder to maintain the correct temperature, which can lead to costly issues over time.

What Causes Coils To Get Dirty?

Coils naturally accumulate dirt and debris over time, especially in commercial environments where refrigeration systems run constantly. Without regular maintenance, this buildup can quickly lead to performance issues.

Here are some of the most common sources of coil contamination:

Dust and airborne particles: HVAC and refrigeration units pull in air that contains dust, which settles on coil surfaces.
Grease and cooking residue: In food service settings, airborne grease can coat coils, especially in kitchens or prep areas.
Pollen and plant matter: Outdoor condenser units are exposed to pollen, leaves, and organic debris throughout the year.
Moisture and condensation: Evaporator coils naturally produce condensation, which attracts dust and promotes mold or bacterial growth.
Improper air filtration: Dirty or missing air filters allow more particles to reach the coils and accumulate quickly.

Understanding these sources highlights the importance of scheduled coil cleaning as part of your system’s preventative maintenance.

How Dirty Coils Affect Commercial Refrigeration Performance

Dirty coils create a ripple effect throughout the entire refrigeration system, affecting the overall refrigeration performance. When airflow is restricted or heat transfer is reduced, the system works harder to maintain the correct temperature. This increased strain can lead to higher energy use, equipment wear, and potential food safety concerns. These problems often develop gradually as buildup accumulates on the coils, making them easy to overlook until performance begins to decline.

Understanding how dirty coils affect different parts of your commercial refrigeration system can help you identify early warning signs. The sections below outline five specific ways that coil contamination can interfere with reliable operation.

1. Dirty Coils Trigger Fault Codes and System Errors

In commercial refrigeration systems, dirty coils can trigger fault codes and system errors by reducing airflow and disrupting the cooling cycle. As dirt and debris accumulate on the condenser or evaporator coils, the system struggles to maintain proper temperatures and pressures.

Sensors detect these irregularities and respond with shutdowns or alarm messages to prevent damage to key components.

2. Reduced Refrigerant Flow Damages Compressors

Dirty coils can interfere with refrigerant flow and place damaging strain on the compressor. When heat cannot transfer efficiently, the refrigerant may fail to evaporate or condense at the proper rate. This imbalance leads to pressure fluctuations and the risk of liquid slugging, where liquid refrigerant enters the compressor instead of vapor.

Slugging and elevated head pressure increase the risk of overheating and internal damage. Since compressors are costly to repair or replace, maintaining clean coils is one of the simplest ways to protect your system and avoid serious breakdowns.

3. Coil Buildup Disrupts Pressure and Valve Operation

Coil buildup disrupts pressure and valve operation by preventing the system from regulating temperature and refrigerant flow consistently. These valves are designed to control the flow of refrigerant, but when coil performance is unstable, the valves may release too much or too little refrigerant at the wrong time. This can lead to poor cooling, frost buildup, and system alarms. The entire system must work harder to compensate, which increases the risk of wear and malfunction.

4. Longer Run Times Promote Mold and Bacteria Growth

When coils are dirty, they cause longer run times that promote mold and bacteria growth by increasing moisture inside the system. This extended operation increases humidity and condensation, especially around the evaporator coil and inside the cabinet. Over time, the excess moisture creates a breeding ground for mold and bacteria, which can impact air quality and contaminate stored goods.

Common signs of microbial growth include:

Musty or sour odors inside the unit
Visible mold near fans or drain pans
Slime or biofilm buildup on interior surfaces

Routine coil cleaning helps reduce run time and keeps your system sanitary.

5. Dirt Buildup Increases Loud Noise and Energy Waste

Dirt buildup increases loud noise and energy waste by forcing fans and compressors to work harder than they should. When coils are coated with dust or grime, airflow becomes restricted and internal pressure rises. As a result, the system operates louder and less efficiently, consuming more energy to maintain its performance.

You may notice:

Rattling, buzzing, or vibrating sounds from the unit
Fans running louder or longer than usual
Unexplained spikes in energy use
Shorter intervals between maintenance issues

Left unchecked, these small shifts can lead to long-term damage and costly repairs.

Best Practices for Cleaning Commercial Refrigeration Coils

Cleaning commercial refrigeration coils is a maintenance task that’s often overlooked until performance problems begin to appear. Many businesses wait for visible signs or system alerts before acting, but by that point, the damage is already underway.

Staying ahead of buildup with a regular cleaning schedule is the best way to avoid downtime, reduce operating costs, and extend the life of your system.

When Do Coils Need Cleaning?

There are several warning signs that suggest your coils need cleaning long before a system breakdown or shutdown occurs. Recognizing these symptoms early allows you to schedule coil maintenance before energy costs rise or refrigerated goods are put at risk.

Some signs to watch for include:

Slower cooling or warmer-than-set temperatures
Unusual noises from fans or compressors
Ice or frost forming on evaporator coils
Unexpected spikes in utility bills
Condensation or water around the unit
System cycling on and off more frequently
Visible dust, grime, or grease on the coils
Refrigeration alarms or temperature warnings on your control panel

If you’re experiencing one or more of these issues, it’s likely time for a professional coil inspection. Routine cleaning helps restore efficiency, prevent system faults, and extend the life of your commercial refrigeration equipment.

How Often Should Coils Be Cleaned?

Most commercial refrigeration systems should have their coils cleaned at least twice a year, though high-use environments may require more frequent service. Factors such as kitchen grease, dusty warehouses, or poor ventilation can accelerate buildup, making quarterly cleaning a more effective choice.

Regular maintenance schedules should also take into account the type of equipment, its location, and the manufacturer's recommendations. Sticking to a consistent cleaning routine helps prevent performance issues and ensures your system stays reliable year-round.

Why Does Professional Coil Cleaning Matter?

Professional coil cleaning plays a critical role in maintaining the performance, efficiency, and lifespan of your commercial refrigeration system. While surface-level cleaning may remove dust and debris, only a trained technician can fully eliminate the grime and microbial buildup that compromise airflow and reduce heat exchange.

Professionals use specialized tools and coil-safe chemicals to clean thoroughly without damaging sensitive components such as fins, wiring, or control sensors. They also use the opportunity to check for deeper issues, including refrigerant leaks, pressure imbalances, or corrosion, which can lead to breakdowns if left unresolved.

With consistent, professional maintenance, your system runs cleaner, colder, and more efficiently. This helps reduce energy costs, protect inventory, and minimize the risk of unexpected repairs.

Keep Your Commercial Refrigerator Running With Clean Coils

When your refrigeration system starts struggling to hold temperature or sounds louder than usual, it’s time to take a closer look. Leading Edge Mechanical Inc is ready to respond with expert coil cleaning that restores performance and prevents costly breakdowns. Whether you’re dealing with slow cooling, system alarms, or unexplained energy spikes, our technicians provide fast and professional service that keeps your equipment running smoothly and efficiently.

Don’t wait for small issues to turn into system failures—address coil buildup early and keep your commercial refrigeration system running at its best. Call (218) 237-5125 today to learn how our professional coil cleaning can improve your commercial refrigeration performance.