How to Insulate Window AC Unit


A window air conditioner is a basic, budget-friendly cooling solution. They do not require installation as they can be placed behind windows with no need for wall alterations or other expensive upgrades you may find in some other air conditioning solutions. They are also quite easy to use, and thanks to the remote control option many models offer, you will never get hot again while trying to adjust your device’s temperature or fan speed.

how to insulate window ac unit

These units typically weigh between 60 and 100 pounds, have extra-large vents for moving hot air out, and provide excellent cooling coverage for rooms around 500 square feet in size. Some models even come with specialized venting kits that allow them to operate efficiently inside bathrooms too! Today I am going to discuss how to insulate window AC unit.

Why Insulate a Window AC Unit?

Window air conditioning units are designed to cool an area of a specific size. The cubic feet capacity is typically given to reflect how much space the unit can cool. However, it’s not just the amount of space its cooling that should matter – but also the temperature of that space! During the summer months, inside temperatures increase dramatically while outside air temperatures remain high.

If you’re using your window AC unit to keep your home cool and comfortable, then investing in insulation will help significantly reduce operating costs and make your home more energy-efficient overall.

Step-wise Guide on How to Insulate Window AC Unit:


Unplug the window air conditioner. And then remove the casing of the unit by unscrewing it with a screwdriver. If you cannot remove any part of the AC, call an expert or fix it yourself. But, be careful not to break off any parts like this one during repair work. Carefully remove the interior of the unit from the casing. Look for the part that is broken and needs to be repaired. It could be the compressor, fan motor, or the air filter.


Clean all fan blades and filters completely because dirt can hamper the insulation of the AC unit.

For cleaning purposes, use masks and gloves for protection against molds and dust particles while wiping each blade individually. It is also worth considering wearing safety glasses as a precautionary measure while cleaning these components since they get dirty really quickly due to the heating effect inside them and bringing in external dust.

Cleaning Filter Of AC


Now, cut or use a chisel to remove the fins of the black box (condenser). Crease the aluminum coil on one side and secure it with a wire for insulation purposes. It is recommended that aluminum foil be used instead of normal cloth or cotton cloth for insulation. It is thicker than these kinds of materials and yields better results after applying heat inside the air conditioner by turning on the AC  unit.


While wrapping the aluminum foil, make sure that you cover the top of the condenser’s black box to be well insulated. Then place the black box on top of the frame and solder all three joints. Do not worry about soldering the bottom of the joint, it will be under the frame in the next step.


Remove any wires or electric components and insulation fan blades in the same manner after cleaning them thoroughly. And then, place insulation material around them by using masking tape for covering creases or holes of an aluminum coil carefully without damaging either the component or the metal coil. It is recommended to use 1″ thick insulation board made from polyethylene foam like this one instead of ordinary materials for better performance insulating window AC unit since they are more durable and get heated up quickly which in turn help cut down electricity usage during operation considerably which benefits users as long as they do not overuse AC.

Remove Electrical Wire From AC


While fixing any part of the unit back into its original place, be careful that no screws or parts should face each other directly while fixing them as they may lead to leakage out of the air inside the air conditioner, which can affect performance and shorten the life expectancy of the unit considerably. For this purpose, make sure that you properly insulate all parts before placing them back into their original places or not use metal foil for insulation since it is electrically conductive.


Packaging every component carefully by making sure there are no loose parts around when reassembling the window AC unit again after fixing insulation material on it properly and making sure you turn off the unit completely before carrying it or placing it back in its original place. Make sure you clean up all of the dried insulation material from inside and outside of the AC window unit before replacing its parts back on. This will keep your air conditioner in a proper working condition for a longer period of time by preventing it from overheating because of excess dust particles around.


Finally, turn on the AC and check if any leaks or improper insulation are being done anywhere during operation that could harm users besides testing if the temperature falls under the desired levels for comfort by using an ammeter.

 If you find some parts inside the air conditioner leaking out heat instead of getting insulated properly with proper materials like this one, then replace them with a new set of parts that have insulation material like aluminum foil placed on them before installation again by unplugging the power connection coming into your window AC.

Precautions While Performing How to Insulate Window AC Unit

Watch Out for Children:

Place something in a position to prevent kids from reaching the window AC Unit because it is dangerous for them to touch or get near the unit during its operation. It is usually best to get a powerful AC unit with short window, and it will save a lot of space in your room. You can put something like a piece of furniture or a box in front of the window AC unit to prevent kids from reaching it.

Don’t Place Any Item on Top of the Window Ac Unit:

Placing objects over your window A/C can cause a problem with proper ventilation and can cause damage to the indoor coil as well. So make sure you keep away all kinds of items like kitchen utensils, water pitchers, vases, etc., inside your home while operating your air conditioner. Not changing your filter regularly can lead to dust accumulation in the system which leads to clogging and a decrease in energy efficiency. Apart from this, it can also cause health problems. Hence, you must change your filter at least once every three months.

Ensure You Remove the Window Coverings:

Takedown all kinds of curtains, blinds, and other coverage from your windows before operating the air conditioner. The curtains and other coverings can block the airflow, which might minimize your AC’s effectiveness. Also, you should remove any furniture and other decorative items that are beneath the air conditioner. These things will obstruct the flow of air from the unit to your residence.

Remove Window Coverings

Don’t Clean the Unit Directly:

Cleaning the metal coil on top with a cloth or wet rag can cause condensation to form inside the unit, which is very bad for its proper working. So please leave it to a professional technician who knows how to clean and take care of a Window AC Unit correctly.

Do not block any openings in front or side panels:

It’s not advisable to place any furniture or electrical appliances near your A/C because it can affect its performance and also block some of its vents, leading to an inefficient cooling system, as they may not provide proper ventilation. It is also not recommended to keep your window open while the A/C is running. This can cause the cool air to escape and allow hot air to enter, thereby making the A/C work harder.

Do Not Operate the Unit With Wet Hands:

It can cause electric shock, skin burns, or any other injury to your loved ones or you.

Advantages and Disadvantages of a Window AC

There are many benefits to having a window air conditioner, but this is not the best choice for everyone. Before deciding on what kind of AC to buy, evaluate the different options and consider all of the following:

The Pros of Having a Window Air Conditioner

+ Provides immediate cooling relief

+ Saves money versus running an entire central system in hot weather (for example, when you come home from work and start using your air conditioning)

+ Easy–to install yourself; no ductwork or permanent installation

+ Lower electrical costs compared with large central systems that run continuously 24/7 during warm months

The Cons of Having a Window Unit

– Because it’s portable, you’ll need to move it around the room as you adjust the airflow

– Expensive to repair or replace; a new window AC unit can cost you upwards of $700. If your electrical system goes out, you may lose the use of this unit until everything is repaired–and that could take days if it’s at all complicated

– Takes up space in your room

Window Air Conditioner Sizes:

The most common size for a portable air conditioner is 5,000 BTUs (British Thermal Units), which cools spaces up to 150 square feet. The next step up in size (usually only available through retail stores) are 7,000 and 10,000 BTU units for rooms that are 200 and 250 square feet. 12,000 BTU models will cool spaces that are 350 square feet, and the biggest size (14,000 BTU) can cool up to 400 square feet. If you have a tiny bedroom without much furniture in it, go with a 5 or 7K unit, so you don’t waste electricity cooling an empty room!

Depending on your climate and habits, keep these other factors in mind when choosing:

* For a more powerful cold blast, look for a unit that’s 10 cubic feet in size; this is an industry standard for portable AC units. Larger models tend to be less efficient because they use extra energy pulling air over long distances through the coils.

For example, a 12-cubic foot air conditioner may have only one inch of refrigerant tubing inside the coil, while a 10-cubic foot unit might have up to three inches of tubing. The larger the AC, the more money you’ll spend on electricity.

+ If the size of your home doesn’t change (such as in an apartment) and you can adjust room temperature using window coverings or fans, opt for a smaller model that will cool only one room at a time.

+ Window units are not designed to cool large spaces; if your place is larger than 350 square feet (with high ceilings), think about getting a central air system instead. Don’t try to use two portable AC units simultaneously–it won’t work! Also, using multiple window units can cause uneven cooling due to different sizes and locations of windows.

Frequently Asked Questions

What Do You Put Around a Window Air Conditioner?

Window air conditioners need a good seal around the window to work properly. You can put curtains, drapes, or blinds in the window to help block sunlight and keep the room cooler. You can also place a screen or curtain over the window if you have pets that might get inside.

Can Window Ac Units Be Left in Winter?

It is generally a good idea to leave your window ac units in during the winter because they help keep your home warm. However, if you live in an area that experiences extreme cold weather, it may be necessary to remove your window ac unit in order to prevent damage.

Will Rain Hurt My Window Air Conditioner?

No, the rain will not hurt your window air conditioner. However, if it starts to rain heavily and the water is coming in through the vents on the top or bottom of your unit, you may need to take action.

If the water is coming in through the vents, you can try to open the windows to let some air in. You can also try turning off the unit and then turning it back on. If that doesn’t work, you may need to call a professional to come out and clean out the unit.

Is It Ok to Spray Water on Your Air Conditioner While Running?

There is no definitive answer to this question as it depends on the climate where you live and the air conditioner you are using. In general, it is not recommended to spray water on your air conditioner while running as this could lead to damage or failure.

What Is the Average Life of a Window Air Conditioner?

Window air conditioners typically last 10 to 12 years, but there are some that last up to 20 years. The average life of a window air conditioner is determined by the amount of use it receives and how well it is maintained.

If your window air conditioner is installed and operated properly, it should last 10 to 12 years. If you have an older model or if it doesn’t get used often, it may last up to 20 years. However, if your window air conditioner isn’t installed or operated properly, it may only last for 3 to 5 years.


As you can see, there’s a lot to know before insulating your window AC unit. If you’re going it alone without professional help, be sure to take notes and read all instructions carefully before you begin. I hope this article has been beneficial in learning how to insulate window AC unit. Thank you and have a nice day!

Jennifer Branett
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