Can Window AC Unit Get Wet? 

Using a window air conditioning unit has many benefits. It uses less energy than a whole-house unit. The window AC unit is easy to uninstall when the need arises or when you move houses in the future.

These units have some disadvantages too. Homeowners worry about the weather inclement causing damage to the window air conditioner. 

So, what happens if my AC unit gets wet? Window AC is waterproof by design, so rain will not harm it. The electrical wires and other interior parts come with high-quality waterproof sealing. But, if the unit is on the ground, flood water can cause serious damage.  

Window air conditioning units offer the next best option for permanent air conditioning. Before you buy one, you need to know as much information as you can find about it.

Keep reading to see everything about these units:

Are Window AC Units Waterproof?

Without standing water, window-mounted air conditioning units are 100 percent waterproof. 

They come with a metallic casing, so they will collect water, but it’ll drain away soon after. If the water fails to drain out, something could be wrong with the outdoor condensing unit or pipe.

A lot or little rain will not harm the window AC units. With age, some air conditioners start to lose their “waterproofness.” Old units require checking more often than new ones. The electrical wires can start peeling away, exposing some parts.

While no rain affects the unit, its installation matters. If yours is closer to the ground, you need to be warier of floodwater getting to it. 

If the installation is above where the floodwater reaches, it is safe. Therefore, there isn’t much to worry about the changing weather patterns.

Can you Run Window AC During Rain?

Whether it’s running or not, the rain is not going to cause damage to the air conditioners. High winds won’t cause damage.

You can keep the units running even when it rains for hours. Some people prefer to switch off their air conditioning when it’s raining.

If this gives you peace of mind, do it. If it rains while you’re at work, don’t panic. The electrical wiring is safe from the rain effects. The cooling coils are safe too.

Don’t worry about leaving the AC running when there’s a thunderstorm. This is fine, too, since thunder cannot cause any harm.

Even if there’s lightning, it need not cause any harm. The electronic components of the window units come with perfect sealing.

If you won’t get peace of mind when you leave the window unit running in a thunderstorm, switch it off. Wait until the rain abates.

What Happens if my AC Gets Wet?

A window unit does not sustain damage from getting wet from torrential or little rain. If the AC unit is still running when it’s raining, there will be no damage.

When it’s windy and raining at the same time, there will be some collected water. The AC grill can collect a lot of debris. This, too, does not affect how it operates.

There can be cause for concern when floodwater gets to the AC unit. Prolonged exposure in standing water can expose the electrical components of the unit.

Will Rain Damage a Window Air Conditioner?

Not even a thunderstorm can damage an AC unit, which you install on the window frame. Whether you get light or torrential rainfall in your place, it will not damage the window unit.

Manufacturers use high-quality material in the construction of the frame. They use corrosion-resistant finishing for the metal parts. The electric wiring and components have water-resistant sealing.

Since the unit stays on the window frame for a long time, it can withstand different weather patterns. These include snow, sleet, and hail. 

Why Window Air Conditioner Stopped Working After Rain

Sometimes, your AC can stop working after getting wet. Manufacturers weatherproof their units well.

With age, your window units might start losing their weatherproof factor. Old units might stop working when they come into contact with a lot of water. Exposed internal parts can prevent it from working.

When it rains heavily, the indoor space will be damp. Humid, warm air in the households has more heat than dry air. You might feel as if the window air conditioner is not cooling the air, as if it is not working. With more damp air, it has to work harder than usual to cool the room.

If your technician installs the AC too low, it can sustain water damage from the floodwater. This leaves the electrical parts vulnerable, and it can cause a short circuit. Rainy conditions might not damage the appliance, but exposure to standing water will. 

Should you Cover your AC Unit?

Using special covers for your unit can help keep debris out when the wind blows. You don’t need to cover this appliance against heavy rain, snow, or hail.

If there are trees nearby, the leaves and seeds will blow into the unit. The leaves start rotting soon after. They can also cover the drain hole. This prevents water from draining out, and it can cause mold growth.

If you do not get the special covers, you can make breathable bags to cover the unit.

Plastic wraps can also keep the water out if your unit is old. The only problem with these wraps is moisture collection, which can cause rusting.

If the interior components are too old, use a garbage bag to cover the unit’s exterior. 

Can you Run Window AC During a Thunderstorm?

If you live in an area with lightning, it is better to switch off the unit when it’s raining. Lightning strikes can cause falling trees, putting your unit in danger. If rainy weather conditions in your area do not cause lightning, you can run the AC.

Before installing one, you need an HVAC technician. A technician can select the best window frame for your AC. They will know how to keep it safe from extreme inclement weather.

Why is Window AC Full of Water After Rain?

Sometimes, after heavy rains, your unit for air conditioning can be full of water. This is a cause for worry for many people.

Unless the AC allows floodwater to get in after heavy rains, it should not be full of water. It can withstand wet weather conditions. If there is collected water inside, there can be several causes.

One of them is the position. The AC pitches forwards towards the inside of the room. The water it collects from the rain does not get back to the drain hole. Even when the rain stops, the water remains inside. This water can leak inside the house.

The main reason for having water in the AC is a faulty condensation drain. If there’s a blockage, the water that gets into the unit will not drain out.

Inside the unit, there is a drain pan. It collects the water that gets inside. The water then goes to the drain pipe. Leaves and other debris can block the drain hose. The water does not find a way out, accumulating inside the unit.

If you use a garbage bag, you should uncover the system as soon as the rain is over. Garbage bags cause condensation when the heating starts to run. This condensing moisture will drip onto the interior components of the unit.

How to Protect Window Air Conditioner from Rain

Even if rain does not damage a window air conditioner, you still need to protect it. Covering it is a good option.

Covering the unit can help with protection if the interior parts are exposed. Avoid using plastic wraps or garbage bags to wrap the window air conditioners. So how can you cover it? Find out below:

Do not cover it all the way

Even if you get your breathable covering, do not extend it to the bottom of the window air conditioner.

You should extend it to about 6 inches from the bottom. This will leave room for fresh air to circulate inside the unit. Condensation will not form easily. Too much of it can cause the metal parts of the air conditioner to start rusting.

Use a breathable cover

If there is a storm, it will whip leaves and other debris around your home. You need a covering to prevent leaves from getting inside the unit.

Protect the system during fall when there is a lot of debris from the falling leaves. If these get into the system, they can clog the drain hose.

One example of a breathable covering material would be canvas material. This is breathable yet protective at the same time. It’ll prevent moisture from forming since it can freeze on the condensing coils.

How to Insulate Window Air Conditioner

Fall is the perfect time to start insulating your window air conditioners. This will prevent it from cooling your home in winter. The air is already cold enough.

Buy the right covering material. You need weather stripping tape, plastic, double-sided tape, and measuring tape. Wrap the exterior of the window air conditioner with the covering material.

The plastic material seals the window to protect your home from moisture. Install the exterior covering and tape it up tightly. This will prevent the cool air from outside from entering your home through the AC system.

Seal every part of the window using your material and the double-sided tape.

Window AC Maintenance Tips

You need to maintain the AC to enhance its lifespan. Protect the compressor and the electrical components. The exterior parts of the system need minimal protection from extreme weather conditions.

Start with the easy things, such as cleaning the unit. You will need a spray bottle to direct the cleaning solution to the greasy spots.

Check the hose for the blockage to prevent AC leakage. After a storm, inspect the system for debris and hail. Proper maintenance has a positive impact on the lifespan of the AC unit.


The wet season is not going to cause damage to your AC unit. Ensure the air-con system is not standing in floodwater. If this happens, switch it off until the water recedes. 

Inspect the system to ensure the sealing of the electrical components is intact. If the electrical parts of the unit get into contact with moisture, you can get a short circuit.

When the system is new, don’t worry about storm exposure. Instead, install it correctly, so the water drains out.