HVAC coils are responsible for transferring heat between the air and the refrigerant. When they get dirty, it can lead to reduced efficiency, higher energy bills, and even system failure.

That being said, cleaning AC coils can be a daunting task, especially if you’re not familiar with the process. So to help you out, we’ve created this ultimate guide on how to clean HVAC coils.

Types of HVAC Coils

To learn how to clean air conditioner coils properly, you need to know which type of coil you’re dealing with. There are two types of AC coils, evaporator and condenser. Each plays a different role in the central air conditioning process, and each requires a different maintenance approach. So let’s briefly take a look at their differences.

Evaporator Coils

Heat and evaporator coils help cool and dehumidify the air that passes over them. They’re located on the indoor unit of the air conditioner, and they’re typically made of copper or aluminum fins.

Over time, AC evaporator coils can accumulate dirt, dust, and other debris. This can reduce their ability to perform during the heat transfer process and lead to increased energy bills.

Condenser Coils

Meanwhile, outdoor condenser coils are responsible for releasing the heat absorbed by the refrigerant into the outdoor air. They’re located on the outdoor unit of the air conditioner and also usually made from copper or aluminum fins.

As with the evaporator coils, air conditioner condenser coils can eventually become dirty and clogged with debris. This also makes the air conditioner work harder, not to mention leads to increased energy consumption.

Differences Between Evaporator and Condenser Coils

  • The evaporator coil assembly is located on the indoor unit of the air conditioning system, while the condenser unit are on the outdoor section.

  • The evaporator coil absorbs and transfer heat and moisture from indoor air to cool and dehumidify it, while the condenser coils release it.

  • Evaporator coils are typically colder than the air passing over them, while condenser coils are hotter.

  • Evaporator coils can be harder to access for cleaning, while the access panel for the AC condenser unit is easier to find.

Signs Your HVAC Coils Need Cleaning

While learning how to clean HVAC coils, bear in mind that here are several signs that they need cleaning. From reduced airflow to unusual noises coming from your HVAC system, you need to recognizing these signs ASAP. Otherwise, your AC unit might end up with more serious issues.

Reduced Airflow

When aluminum or copper coils become clogged with dirt and debris, it restricts the flow of air through the system. This can cause a decrease in cooling efficiency and airflow from the air filters and vents.

Additionally, reduced airflow can cause your air conditioner’s evaporator coil to become too cold. This can lead to ice buildup, potentially damaging the unit.

Increased Energy Bills

When your AC’s coils become clogged, it restricts the flow of air through the system and cause your unit to use more energy to achieve the desired temperature. This can result in a spike in your energy bills without a corresponding increase in usage.

As if that’s not enough, dirty coils can also lead to increased wear and tear on your HVAC system. This will eventually shorten the lifespan of the unit.

Uneven Cooling or Heating

When air conditioner coils become swamped with dirt and debris, it can cause some areas of your home to receive less conditioned air than others. This can result in uneven cooling or heating, with some rooms feeling too hot or too cold compared to others.

What’s more, dirty coils can cause your HVAC system to work harder and less efficiently. This can exacerbate the problem of uneven temperature distribution.

Strange Noises

Dirty air conditioner coils can cause your entire system to work harder and strain just so warm or cool air continue to circulate in your home. As air is forced through the clogged coils, this can lead to unusual sounds such as banging, rattling, or hissing.

Furthermore, dirty coils can cause your system’s fan motor to work harder than necessary. This can also lead to strange noises coming off your unit.

Ice Build-Up

Dirty air conditioning coils can cause the evaporator coil (and sometimes even the condenser coil) to become too cold and freeze over. This can lead to ice buildup on the outdoor unit, causing damage to the unit and reducing its efficiency.

A frozen coil can also cuse your air conditioner to stop working altogether. This opens you up to dozens of nightmarish AC-related problems.

Unpleasant Odors

If you fail to clean your AC coils, they become a breeding ground for bacteria and other microorganisms. This will cause unpleasant odors to come off your AC coils and unit, circulating throughout your home.

Left unchecked, the mold and mildew will thrive and grow on your dirty evaporator and condenser coil, again leading to musty or unpleasant smells. These odors can be particularly noticeable when you first turn on your air conditioner after it has been inactive for a while.

Short Cycling

If you don’t clean AC coils regularly, you’ll cause the entire system to overheat and shut down prematurely. This leads to your air conditioning unit to cycle on and off more frequently than it should.

To top it off, this short cycling can also lead to increased wear and tear on the unit and a shortened lifespan of the system. And it can cause your energy bills to increase without a corresponding increase in usage.

Reduced Indoor Air Quality

Failing to clean condenser coils and evaporator coils can cause your AC unit to circulate contaminated compressed air throughout your home. This can lead to increased dust and allergens in the air.

Dirty coils can also cause your air filter to become clogged more quickly, reducing its effectiveness at capturing airborne particles. This can lead to reduced indoor air quality, which can be particularly hazardous for individuals with allergies or respiratory issues.

Tools Needed to Clean AC Coils

As you can see, knowing how to clean HVAC coils is an essential part of maintaining the efficiency and longevity of your air conditioning system. To properly clean your evaporator and condenser coils, you’ll need a few specific tools to ensure the job is done effectively and safely. These include:

  • Screwdriver or hex driver. These tools are used to remove the access panels on the AC unit during the coil cleaning.

  • AC coil cleaner. This is a specialized cleaning solution designed to break down and dissolve dirt, grime, and other buildup on the coils.

  • Spray bottle. This is where you can pour the commercial cleaners so you can apply it more effectively.

  • Garden hose. A garden hose with a spray nozzle attachment is used to rinse off the cleaning solution and dislodge any remaining dirt and debris.

  • Soft-bristled brush. This is used to gently scrub the coils and remove any remaining buildup.

  • Safety goggles and gloves. To protect your eyes and hands from any cleaning solution or debris that may be dislodged during the cleaning process.

  • Fin comb. This is a tool used to straighten bent coil fins in your AC system, which can improve the airflow through the unit.

  • Wet or dry vacuum. This can be used to clean up any excess water or debris that may be left on the copper or aluminum coils after the cleaning process is complete.

Steps to Clean AC Coils

Knowing how to clean HVAC coils is an essential part of good air conditioner maintenance. The process involves several steps to ensure the evaporator and condenser coils are thoroughly cleaned without damaging them. Below, we outlines these steps needed to clean AC coils, from preparing the unit for cleaning to rinsing off the cleaning solution.

  • Turn off the power. Before cleaning the AC coils, turn off the power to the AC unit to avoid any electrical hazards.

  • Remove debris. Remove any debris or leaves from around the AC unit to prevent it from getting inside during the cleaning process.

  • Remove access panels. Use a screwdriver or hex driver to remove the access panels on the AC unit, so you can access the coils.

  • Apply AC coil cleaner. Spray the coil cleaner onto the coils, ensuring that it covers the entire surface of the coils. Use the spray bottle if necessary.

  • Let the cleaner sit. Allow the AC coil cleaning solution to sit on the coils for the recommended amount of time specified by the manufacturer.

  • Rinse off the solution. Use a garden hose with a spray nozzle attachment to rinse off the liquid or foaming coil cleaner thoroughly.

  • Straighten the coil fins. Use a fin comb to straighten any bent fins on the coils, which can improve the airflow through the unit.

  • Let the coils dry. Allow the coils to dry completely before replacing the access panels and turning the power of your AC unit back on.

Safety Precautions While Cleaning AC Coils

As you learn how to clean HVAC coils, it’s also essential to remember the appropriate safety precautions. After all, the cleaning process can involve working with cleaning chemicals, high-pressure water, and electrical components, which can be hazardous. below are some of the most important safety precautions to keep in mind when cleaning AC coils:

  • Turn off power. Always turn off the power to the AC unit before starting to clean the coils to avoid any electrical hazards.

  • Wear protective gear. Wear protective gear, such as gloves and safety glasses, to avoid any injury from the cleaning chemicals or debris.

  • Use appropriate cleaning solutions. Use the appropriate cleaning solution for the type of coils you are cleaning, and follow the manufacturer’s instructions for use and handling.

  • Use a ladder or scaffolding. Use a sturdy ladder or scaffolding when working at heights to avoid any falls or injuries.

  • Be mindful of electrical components inside. Be careful when cleaning around electrical components, such as the fan motors, AC filters, and wiring, to avoid any electrical hazards.

  • Use high-pressure water carefully. Be careful when using high-pressure water to avoid damaging the coils or other components.



What is the best way to clean HVAC coils?

The best way to clean dirty condenser coils and evaporator coils is to turn off the power, remove any debris, apply coil cleaner, rinse off the cleaner, straighten the bent fins, and let the coils dry completely. It’s important to also follow safety precautions, such as wearing protective gear and turning off the power, to avoid any accidents or damage to the air conditioners.

Can I clean my air conditioner coils myself?

Yes, you can clean your AC coils yourself if you have the necessary tools and knowledge. However, it’s important to follow safety precautions and manufacturer’s instructions to avoid damaging the dirty AC coils and the air handler unit or putting yourself at risk of injury.

How often should HVAC coils be cleaned?

The frequency of cleaning HVAC coils depends on factors such as usage, environment, and type of coils. However, it’s recommended to clean the coils at least once a year to maintain optimal performance and energy efficiency.

Is HVAC coil cleaning necessary?

Yes, HVAC coil cleaning is necessary to maintain the efficiency and longevity of a good, clean air conditioner. Dirty coils can cause reduced airflow, increased energy bills, and even system breakdowns, which can be costly to repair. Regular cleaning can help prevent these issues and ensure that the indoor air handling unit is working properly.

how to clean HVAC coils