Keeping your air conditioner coils clean is one of the most important maintenance tasks to ensure your AC system runs efficiently and lasts a long time. Dust, dirt, and debris can build up on the coils, leading to reduced airflow, decreased cooling capacity, and higher energy bills. Cleaning the coils regularly helps remove this buildup, maintain proper airflow, and allow your AC to run at peak performance. Follow this comprehensive guide to learn how to easily clean air conditioner coils yourself.

Supplies Needed for Cleaning AC Coils

Cleaning your air conditioner coils is a relatively simple DIY task that doesn’t require many supplies. Here are the basic items you’ll need:

Garden hose with nozzle or pressure washer
Coil cleaning solution or spray cleaner
Soft brush or coil cleaning brush
Protective eyewear and gloves
Drop cloths or towels
Flashlight
Screwdrivers
Replacement air filter

Choosing a coil cleaner specifically formulated for HVAC use will provide the best results. These cleaners contain detergents and degreasers to cut through dirt and grime. Avoid using harsh chemicals like bleach that could damage the coils. An old toothbrush also works well for scrubbing fins.

Preparing to Clean the AC Coils

Take a few simple steps to prep your AC system before getting started:

Turn off power to AC unit at breaker box
Remove any debris or vegetation near unit
Remove outer cabinet panels if possible
Place drop cloths under unit to catch water drainage
Have a replacement air filter on hand

Make sure to turn off power to the AC before servicing to avoid shock. And take precautions on ladder or roof when accessing external condenser unit.

Locating the Evaporator Coils

Air conditioners have two sets of coils—the evaporator coil inside and the condenser coil outside. Here is how to find both:

Inside Evaporator Coil

The evaporator coil is usually located inside the plenum or main supply ductwork downstream of the air filter. Remove any access panels or grilles to expose the coil. Turn on flashlight to inspect fins and dirt buildup.

Some evaporator coils are also behind the furnace or within the air handler cabinet. Consult manual if unsure—evaporator coil needs regular cleaning too.

Outside Condenser Coils

The condenser coil is part of the exterior AC unit. Look for a finned, box-like component made of copper and aluminum fins. Remove any debris blocking condenser coil fins.

Use caution when cleaning condenser coils located high up. Never lean ladder against AC cabinet.

Safely Cleaning Air Conditioner Coils

With prep work complete, follow these safe steps to thoroughly clean AC coils:

1. Lightly Spray Fins with Coil Cleaner

Apply a light mist of coil cleaner to finned coils. Avoid heavy soaking and let sit for a few minutes. This allows cleaner to start breaking down buildup.

2. Rinse Coils with a Garden Hose

Use a garden hose with a pressure nozzle to rinse coils from top to bottom. Flush debris loosened by cleaner through fins.

3. Scrub All Fins with a Soft Brush

Use a soft brush or specialty coil brush to gently scrub fins of condensed coil. Remove any remaining dirt or buildup.

4. Final Rinse

Give coils a final rinse to wash away all debris and cleaner residue. Flushing completely is important to prevent future blockages.

5. Straighten Bent Fins

Use a fin comb tool to straighten any bent coil fins. This restores proper airflow through AC system.

Take care when straightening fins on sharp evaporator coils. Wear gloves and eye protection.

6. Rinse Out Drain Pan

Check the coil drain pan and clean out any dirt or debris clogging the drain line. Use a shop vacuum on closed systems.

This helps ensure condensation can properly drain once the AC is turned back on.

7. Reinstall Cabinet Panels

Replace any cabinet panels, grilles, and access covers once finished cleaning the coils.

8. Restore Power and Change Filter

Restore power to AC unit at breaker box. Install a clean, new air filter before running system.

Take care not to bend or crush evaporator coil fins when replacing panels.

How Often Should You Clean AC Coils?

Here are some recommendations on coil cleaning frequency:

Clean evaporator coils every 2-3 months during cooling season
Annual cleaning for condenser coils
Every 1-2 months if pets or allergies
When replacing air filter
Anytime AC performance declines
After construction or renovation

The exact schedule depends on factors like run time, filter maintenance, and indoor pets. More frequent coil cleanings are a good idea for homes with excessive dust or pet dander.

Visually check the coils at the start of each cooling season as well. Clean any accumulated grime before running the air conditioner.

Signs Your AC Coils Need Cleaning

Watch for these warning signs that your AC coils need cleaning:

Increased energy bills
Higher than normal running times
Reduced airflow at vents
Decreased cooling capacity
AC freezing up or icing over
Excess humidity in home
Musty odors blowing from vents
Leaks or dripping water from unit

Poor airflow and reduced cooling are some of the most common symptoms of a dirty evaporator coil. An extremely dirty condenser coil can cause the AC system to overheat or break down.

Schedule coil cleaning if you notice any combination of these issues to restore proper operation.

Professional Coil Cleaning

For extremely dirty coils or ones needing disinfection, consider hiring an HVAC professional for cleaning. Here are some benefits:

Specialized Equipment

Professionals use high-pressure jets, industrial vacuums, and steam cleaners to thoroughly clean coils and drain pans.

Sanitization

They can apply sanitizing biocide treatments to kill mold and bacteria buildup on evaporator coils.

Structural Checks

A technician will check the coil structure for cracks or damage during cleaning.

Improved Efficiency

Thorough coil cleaning can improve system efficiency by up to 15 percent.

While a professional cleaning has advantages, it also costs $200-$400 on average. DIY cleaning provides good results for much less.

Safety Tips for Cleaning AC Coils

Follow these safety tips when cleaning air conditioner coils:

Turn off electrical power to AC before starting
Work with a partner for condenser coil cleaning
Wear eye protection and gloves
Check ladder or roof for stability before climbing
Avoid getting interior ductwork and electronics wet
Rinse coils and pan with clean water only
Clean up any drips or spills around system

Take precautions on ladders or roofs when cleaning condenser coils. Use extreme care around electrical components and connections.

Having a partner for exterior unit cleaning provides an extra measure of safety.

Common FAQs About Cleaning AC Coils

Cleaning air conditioner coils on your own is easy with the right steps, but some homeowners still have lingering questions. Here are answers to some of the most common FAQs:

How can I clean coils I cannot reach?

Use a coil cleaner spray extension wand for hard-to-reach evaporator coils. Remove any panels possible to improve access before cleaning.

What about blocked condenser coils?

Trim back any bushes or vegetation touching the AC unit. Then rinse debris from condenser coil fins using a garden hose and brush.

Is it safe to use a pressure washer?

Yes, but take care to prevent water from entering internal electrical components. Maintain at least 1 foot of distance.

How do I clean a window AC unit?

Remove the exterior grille covering the filter and controls. Then clean the exposed condenser coil fins located behind the grille using a cleaner spray and rinse.

What if my drain line clogs again after cleaning?

Use a drain line enzyme cleaner monthly to keep algae and biofilm buildup under control between coil cleanings.

Regular coil maintenance is the best way to prevent frequent clogs and keep AC drains open.

Why does my evaporator coil freeze over?

Low refrigerant levels, dirty filters, and excess moisture are common causes of coils freezing. Thorough cleaning and repairs help, but a new AC may be needed.

How can I improve airflow without cleaning?

Make sure nothing is blocking the condenser unit outside. Also replace the air filter, remove vent obstructions, and check ducts for tight bends or kinks limiting airflow.

Performing regular maintenance between deeper coil cleanings helps avoid any major loss of cooling or efficiency due to dirty coils. Your air conditioner will provide better comfort and operate more economically after a thorough DIY cleaning.

Conclusion

Regularly cleaning air conditioner coils helps remove damaging dust buildup and ensures your system runs at peak efficiency all cooling season long. Follow the steps outlined in this guide to easily clean AC coils yourself and improve performance. Just remember to turn off power, lightly rinse coils, scrub away debris, and restore airflow through the fins. Deep cleaning the evaporator and condenser coils every few months will save money and extend the life of your air conditioning system.

How to Clean Air Conditioner Coils