Is It OK to Leave Window AC on All Day?

If you’re one of those people who like to turn their window AC on and forget about it, then there is something you should know…

It is actually totally ok to leave your window AC on all the time. You might not want to leave a working air-con unattended though as there is always a risk of an electricity spike; turning the unit off during a thunderstorm is also a good idea.

Is It OK to Leave Window AC on All Day?

Pretty much all air conditioners are designed to be able to handle 24/7 usage. So, in general, it is ok to leave your window AC on all day.

However, that does not mean that you should make your HVAC unit work at full capacity all the time. Choosing the most optimal temperature and adjusting it whenever you are away would help you avoid the majority of downsides associated with an always-working air conditioner.

Read: Why Window AC Compressor Turns On And Off?

What Happens If You Leave the Air Conditioner on All Day?

No components in the actual air conditioner are going to overheat in case you leave it on all day long. But there are a few things that will happen if you make the unit work at full capacity all the time:

  • Your electricity bill will go up
  • The lifespan of the AC may decrease as every piece of equipment can only be used for a certain number of hours
  • The AC will be harming the environment for longer – HVAC units use a lot of electricity; they can also leak HFCs (these substances are used as refrigerants in a lot of systems)
  • The unit is going to require more frequent maintenance (for example, you would have to clean the unit and empty the drain pan more often)

Can an Air Conditioner Run 24 7?

An AC can physically run 24/7 and the chances are high that nothing is going to happen to your HVAC unit. However, if you don’t utilize the unit wisely, you are going to suffer from extremely high energy bills.

Read: Why Are HVAC Vents Under Windows?

How Long Can a Window AC Run Continuously?

Your window air conditioner can run for as long as you need.

Typically, the compressor will cycle on and off as the temperature in the room changes. And even if the unit never reaches the set temperature (in case the AC is too small for the space) and continues running without cycling off, still nothing bad is going to happen. 

How Many Hours Should Window AC Run Per Day?

If it’s hot outside, you can get away with having your air conditioner on all the time. In fact, that might even be more energy-efficient as a unit that has been switched off would struggle a lot more to reach the set temperature on a hot day once you finally turn it on again

If it’s warm outside, then you might want to consider having your AC on only for a few hours per day (usually, an hour or two before the warmest time of the day). This won’t have as big of an effect on your electricity bill and you’ll be able to keep the temperature relatively comfortable inside. 

Read: What Are 4 Basic Categories Of HVAC Systems?

How Long Is Too Long for an AC to Run?

A lot of air conditioners run for 15-20 minutes before cycling off (you don’t have to turn the unit off manually). Once the temperature increase, the AC will automatically turn on again.

If your unit is not working in these cycles, then it looks like the air conditioner is way too small for your house. The equipment won’t overheat if it never cycles off, but there are other disadvantages associated with undersized heating and cooling units. 

How Long Does AC Need to Rest?

Between the cycles, an AC will usually stay off for around 7-10 minutes. But it’s totally fine if that doesn’t happen – air conditioners don’t really need to rest.

With that being said, you should not fire up an air conditioner right after it had been shut down. This can damage the compressor and motor.

If you turned your AC off, make sure to wait for at least 10 minutes before switching it back on again. 

Read: What Are Types Of HVAC Systems In Hotels?

Should I Turn Off My Window AC During the Day?

You don’t have to turn the air conditioner off (as long as you need it to keep your place at a comfortable temperature). 

However, there can be certain situations during the day when you might want to consider switching the AC off:

  • When you’re away 
  • When you’re sleeping
  • When there is a thunderstorm

Is It Ok to Run a Window Air Conditioner in the Rain?

Rain can’t affect your window air conditioner or its performance. All the electrical components that can, in theory, get damaged by water are sealed.

Standing water, however, can damage HVAC equipment. If there are over 15 inches of water, some of the components might not be able to function.

In such a case, you might want to turn your unit off and call an HVAC technician once the water recedes.

Can I Leave My Window AC on When I’m Not Home?

Due to safety reasons, you might not want to leave the window AC unattended as there is always a risk of an electricity spike.

Is It Ok to Leave Air Conditioner in Window During Winter?

You should remove your window AC if you live in an area with harsh winters. Snow and ice can damage the equipment.

If you live in an area where winters are relatively warm, you can safely leave the unit out (make sure that the temperatures don’t drop below 62 F though). 

Read: What Are Zoned HVAC Systems?

Can I Leave My Window AC on During a Thunderstorm?

It is relatively safe to continue using your window AC during a thunderstorm, but there is a possibility of the unit being struck by lightning. Especially, if you live in a high-rise.

How Much Does It Cost to Run a Window AC 24 7?

It can cost you anywhere between $0.06 and $0.36 per hour to run a window air conditioner. 

By the way, some experts say that running your AC 24/7 is actually cheaper than turning the unit on and off multiple times during the day. Simply try to keep the set temperature at 78 F.

How Much Does a Window Unit Increase Your Electric Bill?

On average, this type of air conditioner will cost you $40-$100 per year to run. 

How Do You Use a Window Air Conditioner Efficiently?

  • Invest in a programmable thermostat – this device will change the temperature when you’re out, for example, without making the AC start and stop frequently
  • Get the right window air conditioner for your home – your unit shouldn’t be undersized or oversized
  • Close your doors to ‘lock’ the cooled air in one space
  • Insulate the windows to make sure that the conditioned air doesn’t escape

Should You Put a Fan in Front of a Window Air Conditioner?

A fan in front of your window AC will help circulate the cooled air around the room. This will help maximize the unit’s cooling effect

Can a Window AC Unit Overheat?

A dirty condenser coil and low refrigerant levels can make an AC unit overheat. 

A correctly working air conditioner can actually stay on all day (and even longer) without the risk of overheating.