How To Clean Window AC Unit – Step-by-Step Guide

| Last Updated: June 13, 2021

Is your window air conditioner clean? Window AC units are an efficient method to combat hot weather in climates with short summers.

However, they need to be cleaned regularly for top performance and to maintain adequate indoor air quality.

Consult this step-by-step guide for cleaning your window-installed AC unit and be confident in your air quality.

Project Metrics

Here’s some helpful information on this project. 

Working Time

15 minutes to 1.5 hours

Prep Time

Up to 10 minutes

Skill Level

Beginner to advanced

Material Cost 

Up to 20 USD

How to Clean a Window AC Unit

Dirty AC units can pose several risks to you and your family. The main one is, of course, the mold and air pollutants. Another consideration is that the appliance requires more power to operate if it’s dirty. Besides, a clean AC will last longer and work quieter.

Depending on how dirty the air conditioner is, you might need to perform one of the following cleaning methods.

Basic Cleaning

This cleaning method is an easy way to keep the conditioner in good shape during the season and ensure that you prevent dirt and mold buildup. You can perform this without removing the unit and in about 15 minutes. Let’s go step-by-step:

  1. Turn off the AC and disconnect from the power source: Initiating cleaning is dangerous with the appliance turned on.

  2. Pour a 3% hydrogen peroxide solution in a spray bottle: This substance is non-toxic, anti-allergy, and cheap. Some sources recommend using chlorine bleach, but it’s too risky if you’re not going to thoroughly rinse the whole unit. Never mix hydrogen peroxide or ammonia with bleach.

  3. Spray the solution on all the surfaces: There’s no need to open the unit for this method. You’re just disinfecting the appliance. Let the solution sit on the AC and do its job.

  4. Let the AC dry before turning it on again: If you turn on the appliance before it’s dry, there’s a risk that you’ll inhale the fumes of the spray. It’s safer to do this overnight and let it air dry.

Quick Checkup

A more thorough clean is due monthly, as the filter might gather dust and mildew during that time. 

This method is all about making sure that you follow the manufacturer’s instructions on filter maintenance.

For this method, you’ll need

  • a vacuum cleaner

  • the peroxide solution as in the previous step

  • a tray, or a bucket to catch drips
Photo credit:

Depending on your AC, a screwdriver might also be handy. The process won’t take you more than 30 minutes. Below are the steps for success:

  1. Turn off and disconnect the appliance as described above.

  2. Remove your AC unit’s front panel: If the machine doesn’t have a front casing, you can skip this step.

  3. Take out the filter and examine: The filter might need vacuuming. However, if you feel there’s mold or mildew smell or see any buildup, it may be time to soak the part. 

  4. Clean the filter using one of the following methods:

    1. Access the filter, take it out and vacuum it on both sides. This is a quick way to do  a mid-season cleanup and regular maintenance

    2. Soak the filter in a vinegar or detergent solution to, rinse, and let it air-dry. This is a very efficient way to do a deep clean before re-installing back into the appliance.

    3. You can attach a showerhead to a garden hose and spray the filter top to bottom. Caution: Pressurized nozzles can damage the filter.

  5. Vacuum and wipe the insides: If there’s too much dust, wiping will prevent turning it into mud during the next step.

  6. Spray the hydrogen peroxide solution inside the air conditioner: Place the tray under the appliance to keep the drips from spoiling your floor or furniture.

  7. Wipe or scrub: Use a soft-bristled brush if necessary.

  8. Let the filter and all the parts air dry before re-assembling: The filter must be completely dry before you start using the conditioner again.

Caution: Never turn on the AC without a filter

Photo credit:

Deep Cleaning

Suppose you’ve taken the AC unit out of the storage box and discovered that it contains mold and dust. In that case, it’s time for the seasonal deep cleaning session. This task might require more effort and take you up to 1.5 hours.

You might need assistance if you have problems handling heavy objects and household tools. Besides, people with allergies might need help from a professional.

  1. Turn off and disconnect the power source.

  2. Remove the casing: You might need a screwdriver to take it apart.

  3. Remove the filter: Use a proper method to clean the filter, depending on how dirty it is. You can also change the filter according to manufacturer recommendations. A filter lasts for about three months.

  4. Comb the fins: Wear work gloves to avoid cuts.

  5. Use pressurized air: Blow out the dirt between the fins.

  6. Or use a vacuum cleaner: Swapping pressurized air with a vacuum cleaner is also acceptable

  7. Vacuum the casing: This’ll get rid of the clumps of dirt and debris.

  8. Spray and wipe all the surfaces: You can use soapy water or the hydrogen peroxide solution mentioned above. If the appliance is too moldy, we recommend using a weak bleach solution and a soft brush to eliminate all the spores. See below for more about cleaning mold out of the AC unit.

  9. Use a garden hose to wash away dirt: Get the conditioner out to a backyard and let the water do its job.
Photo credit:

10. Wipe it dry: The conditioner needs to be completely dry before you assemble it to avoid rust and buildup around the screws. You can also let it air dry.

11. Reassemble the AC: If you’ve kept all the parts and screws and have a decent screwdriver, this step will be a breeze.

12. Set up the unit: The conditioner will work wonderfully after such a thorough cleaning.

How to Clean AC Coils

While we’ve given a more detailed description of how to clean the coils, here’s a quick summary of approaches you can take. Depending on how dirty the coils are, you might have to choose from the following ways:

  • Compressed air: It’s an efficient and quick way to get rid of mild dust and dirt buildup.

  • Soft-bristled brush: Sweep the dirt away using gentle force.

  • Commercial cleaners: Use as indicated in the manufacturer instructions.

  • Mild detergent solution: If you want to avoid commercial cleaners, a DIY solution can be efficient as well.

  • Professional cleaning: If the coils are too dirty or inconvenient to access, employ a specialist to clean them for you.

How to Clean the Air Conditioner Filter

Much like the coils, there are several ways to clean your AC filter. First of all, you need to ensure that the manufacturer allows it, and then find the preferred method. The user’s manual usually contains that information. Here are a few ways to approach the task:

  • Use a vacuum cleaner.

  • Soak it in a weak vinegar, bleach, or hydrogen peroxide solution.

  • Use a garden hose to wash off the dirt.

Some filters also have an automatic cleaning function. Activating it according to the manufacturer’s instructions will extend your AC filter’s service time and save you time in the process.

Photo credit:

How Do You Clean Mold Out of a Window Air Conditioner?

Mold is a dreaded problem for AC owners, as it can accumulate and gets everywhere. Monthly checks are essential to ensure that you keep mold spores at bay. Now, let’s break down the steps you should take if mold has already crept in:

  • If the appliance is mounted, turn it off and remove it from the window.

  • Take the appliance apart.

  • Wash both sides of the filter with a mild detergent.

  • Unscrew all parts to reveal the mold buildup.

  • Mix one tablespoon of mild dish soap and ½ cup bleach into three gallons of hot water.

  • Dip a brush or sponge into the mixture and scrub the buildup.

  • Leave the solution on the AC for about ten minutes to make sure it kills all mold spores.

  • Rinse the unit parts, wipe them with a towel, and let them air dry.

  • Reassemble the unit.

Caution: Working with bleach can be dangerous to your skin, eyes, and clothes. Use protective gear like goggles, rubber gloves, and a mask.

Photo credit:

Cleaning a Window AC Unit Tips, Tricks, and Hacks for Success

Below are a few quick tips and essential tricks to ensure your air conditioner’s service quality, operation efficiency, and longevity.

Deep Clean Before Installing

We recommend cleaning the conditioner before the season to ensure its uninterrupted operation and consistent indoor air quality. Dirty conditioners can be dangerous for your health.

Conduct Monthly Checks

During the season, the monthly checks will keep your AC clean at all times. Take out and at least vacuum or change the filter, wipe the outside casing, and spray the condenser. Adopting these small habits will extend your AC unit’s service time.

Follow Storage Instructions

Store your air-conditioned in a cool, dry place.

Is it Ok to Spray Water on Your Air Conditioner?

Spraying water on your AC is one of the most efficient ways to clean it without removing it. The indoor unit and the condenser can take water droplets as long as it doesn’t contain other components. The condenser should cool more efficiently if you spray water on your AC from time to time.

Can I Pressure Wash My Air Conditioner?

Although you can use your garden hose to wash the unit, make sure that the water stream is gentle. A pressure washer may be too strong and damage the coils, fins, and other components.

Photo credit:


The air quality in your home is critical to your health and wellbeing. Dirt and mold in your AC unit can pose risks to you and your family, cause allergies, and be generally unpleasant. If you follow our tips and tricks, you can keep your AC unit clean and efficient.

People Also Ask

This article has given you a detailed step-to-step guide to cleaning your window AC unit. However, here are a few other frequently asked questions to help you get it done.

How Often Should a Window Air Conditioner Be Cleaned?

It’s crucial to deep-clean the AC after taking it out of the storage box and before you mount it on the window. If the conditioner is mounted permanently, a seasonal cleanup is what it needs. During hot months, when used regularly, a monthly checkup is enough. 

What Do I Need to Clean My Window AC?

Cleaning supplies like a bucket of water, dish soap, a soft brush, a spray bottle, an old cloth or a paper towel, and a screwdriver might be handy. If the appliance is too dirty or moldy, prepare bleach or hydrogen peroxide to treat it. Ensure that you’re protected as well. Wear gloves, protective goggles, and a mask.

Do I Have to Remove My Window Air Conditioner to Clean it?

No. However, it’s preferable to do so before sending it to storage and after taking it out. If you need to give it a quick check and clean it in the middle of the season, you can clean your window AC while it’s mounted. 

My name is Bob Wells and I am a retired HVAC tech from Washington state. I am currently retired and no longer do much with HVAC, however, I feel like I have a lot of knowledge in the subject and I wanted to create a website where I could talk about what I've learned and help upcoming HVAC techs. Find more info about me and HVAC Training 101.