Does AC Fan Bring In Outside Air?

Air conditioners are the heroes we all need during the hot summer weather. You probably know how unbearable it can be to stay or sleep in your house when the weather is too hot. This is why most people opt for air conditioners to help cool them off in their homes and provide a pleasant environment.

But, in as much as air conditioners are beneficial, they also come with their drawdowns. For instance, most people don’t know whether an AC fan brings in outside air or not. It’s important to note that air conditioners function quite differently from fans and other cooling appliances. 

However, this doesn’t mean that they are inefficient. You need to understand that every home appliance is built differently and operates in its unique way. Therefore, clearly understanding this will help you purchase an appliance that will serve you properly and has what you need.

An air conditioner’s main objective is to offer you cool air when it’s too hot and circulate warm air during the cold winter season. It’s safe to say they are efficient and reliable, except for the fact that they can increase your electricity bill if you’re not careful.

So, Does It Bring In Outside Air?

The answer to this question is no. Your air conditioner doesn’t bring in outside air or fresh air from outside. This is because air conditioners are not designed to bring in fresh air from outside. What happens is that your AC uses a fan to draw air into it and then disperse it through a structure.

Therefore, this results typically in recycled air. The air that is sucked in passes through coils before it goes into your home. The coils are the ones that cool the air. In terms of the freshness of the air, the outside air is potentially packed with harmful elements. These elements normally trigger asthma, allergies, and many other symptoms. 

The good news is that before this air enters the house, it passes through an air filter used to trap pollutants and make it healthy to breathe in the air. When that happens, it helps keep the people living inside that house healthy and prevents allergic symptoms and even asthma. Therefore, it’s safe to say that the air filter is very beneficial and offers the best assistance in the air we breathe.

Removing the Hot Air

When it comes to removing the hot air from your house, the air conditioner pumps it outside through the heat pump, which usually operates in either direction. It moves heat or thermal energy outside during the summer season and inside during the cold winter season. How does it do it? The AC’s pump (compressor) sucks the warm air out of your room/home. 

This removes the hot air outside with the assistance of the refrigerant. The refrigerant is encased in a closed metal loop, and it provides a shuttle for the exchange of heat. 

How the AC Keeps You Cool

The cooling process of an air conditioner is known as the refrigeration cycle. This type of heat exchange features a series of changes in pressure, temperature, and state. This, in turn, helps to get rid of the heat from your home. There are four stages in this cycle, and they include:

  • The refrigerant absorbs the heat from inside your house.
  • When the refrigerant absorbs the heat, it becomes hot.
  • Transfer of heat through the refrigerant happens, and it flows from warmer to the cooler area so that it can be released to the outside air.
  • The refrigerant becomes cold, and it’s then distributed through your house by other system components.

What Are the Changes?

When this refrigerant passes back into the house, it passes through a narrow valve and into the evaporator, usually kept at low pressure. This means that when the refrigerant flows in, it expands faster. It is this expansion that causes the fluid to become cold. A fan blows air on it and distributes it through ductwork in your home.

This is also part of the heat transfer because when the cooled air is distributed, the air that is blown onto the evaporator from the return ducts transfers heat into the fluid. Then, the refrigerant is pumped back to the condenser, and the cycle begins again.

Although there are different types of air conditioners on the market, they function similarly to each other. These air conditioners are not designed to bring in outside air, as most people would assume. The recycling of the air is what keeps you cool or warm during the summer and winter seasons.

Do You Need Additional Ventilation?

Judging by the information I’ve provided here, it’s obvious you would wonder whether you require additional ventilation. Unfortunately, there isn’t any direct answer to this question because it depends on your needs. For instance, additional ventilation installed by an expert might end up lowering your utility bills as it reduces your cooling needs or even improve the air quality.

Therefore, the function and style of that ventilation tend to vary depending on your home’s age and construction, or even the health and comfort needs of your family. Due to such a case, you may want to talk to a qualified and trusted professional to understand these opportunities. 

When it comes to using an air conditioner, it’s also important to check on the type suitable for your home. There are window ACs, central ACs, portable ACs, ductless and hybrid air conditioners, and geothermal heating and cooling.


So, does AC fan bring in outside air? Absolutely not! I’ve shown you how air conditioners are made to recycle the air they make and provide you with what you need – either cool air or warm air. Therefore, it’s important to understand this mechanism about air conditioners to refrain from assuming that they get their air from the outside.

If you happen to have any questions or anything to add, you can send them in the comments section below. You can also reach out to me through email, and I’ll be happy to respond.