How Ventilation Occurs with a Split Air Conditioner

split air conditioner vent up close

Without air conditioning, wouldn't the summer months be impossibly miserable? You probably know how to turn the AC on, but do you know how ventilation occurs with a split air conditioner?

How ventilation occurs with a split air conditioner depends on a few factors because they don't all work the same way. It's useful to know exactly how ventilation occurs, how much ventilation the system needs, and what you can do to make sure the AC is functioning at its fullest.

How Split Air Conditioners Work

A split air conditioner is made up of two separate parts that are connected but not adjoining. The indoor unit, or evaporator, is separated from the outdoor unit, or condenser.

The evaporator is inside the room where your HVAC system is located, usually a laundry or utility room. Cold air entering the evaporator is pushed into your home through ducts and vents, cooling the rooms and making summer bearable.

The compressor is outside the house, in a different area of the same room, or it's located elsewhere in the home. It may be sitting on the ground or attached to an outside wall.

Copper pipe and electrical wiring keep the two units connected. The refrigerant is moved through the copper pipe from the outdoor compressor to the condenser and then into the evaporator.

The compressor pulls warm air from the room, and refrigerant, or cooling liquid, cools down the air before it is pushed into your home through vents.

Think of it like this: the condenser unit that is outside the home pushes coolant into the evaporator inside. The evaporator pulls the warm air out of the room so that the coolant can cool it down.

The cooled air then comes back out of the evaporator, where it is pushed through ducts to all parts of the home.

It is a pretty complicated system, because this is just a rough outline of everything that’s going on with an air conditioner, so it’s easy to have questions about where the air is coming from and where it’s going. How does ventilation occur with a system like this?

Ductless Mini Split Systems

A ductless, mini-split air conditioner also has two parts: the outside condenser and the inside air handler. This small, compact system can keep a single room or small area of the home cool.

Ductless mini-split systems are quiet and small. They're also energy-efficient, which is why they are an attractive choice for many homeowners.

The outside condenser is not responsible for sending outside air through the system into the home. It is only responsible for delivering the coolant to the other component of the air conditioning system.

In the case of ductless mini-split air conditioners, the air handler draws air from within the room so that it can be cooled down by the coolant. The cooled air is then sent out into the room.

Both ductless mini-split systems and standard split air conditioners work the same way by cooling the air inside the home rather than drawing in air from the outside.

In other words, these split air conditioners are not bringing air from outside into your home. The air that is already in the room is circulated through the system.

Since these systems are not designed to pull fresh air from outside, you need to know how ventilation occurs with a split air conditioner.

Split Air Conditioners and Ventilation

Because they are closed systems, split air conditioners do not have ventilation pipes and do not require them in order to function properly. No exhaust or fumes is being released from the part of the system that is inside your home, which eliminates the need for ventilation.

The air that is being drawn into the system is the same air that is being delivered to the inside of your home, so the same air is being circulated again and again.

Due to the way split air conditioners are designed, the system itself does not need ventilation and does not have any. Split air conditioners are not dependent upon air from the outside world and do not need to eliminate hot air into the outside world, so ventilation is not necessary.

As long as the AC is functioning the right way, it will always have all the airflow it needs because it is drawing air from the room.

However, human beings do need some ventilation. While split air conditioner systems are not ventilated and do not need it, you and everyone inside your home certainly do.

split air conditioner on wood wall

Why You Need Ventilation

Energy efficiency is at the front of every discussion about the home. Everyone is looking for ways to reduce utility bills, use less energy, and get more clean energy.

There's a big emphasis on creating a tight building envelope in order to prevent heat loss. A tight envelope is always at the top of the list of recommendations for being more energy-efficient.

Sealing air leaks, caulking around windows, and taking other steps to create that tight envelope will absolutely reduce utility bills and make your home more energy efficient overall.

But that tight envelope means that homes are not well-ventilated, and ventilation is something human beings need. You don't want to breathe the same air all the time, as this can circulate viruses and aggravate existing problems like asthma and allergies.

Breathing stale air can create headaches and may even cause rashes on the skin because it's not good for you. All humans need to breathe fresh air sometimes.

Bad odors from cooking and a generally stale or musty odor can linger in rooms of the home without proper ventilation as well.

There are many reasons why you need ventilation, even if your air conditioner does not.

How to Ventilate Your Home

So, what's the solution? If your air conditioning system doesn't bring fresh air into the home and it doesn't have its own ventilation, how can you create ventilation in your home for yourself?

The easiest way to get ventilation is to open the windows. Try to open two windows across from each other to get air flowing through the home, if possible, and create a bit of a breeze.

You don't want to leave windows open all the time, because a tight building envelope is key to keeping your home energy efficient. However, it's a good idea to open some windows and air your home out every few days.

Turn off the AC or the heat when you’re going to ventilate your own. Otherwise, the money you spend on your utility bill will be leaking right out of the windows.

An hour's worth of ventilation every few days will keep the air in your home fresher and healthier. If you’re going to open windows, make sure they have screens on them to keep birds, bugs, and other critters and insects out of the home.

If you haven’t got screens, crack the windows open only slightly. Crack open as many windows in the home as you can, since the house will be receiving less airflow with these small openings.

However, it’s important to remember that outside air will bring pollen and other allergens into the home environment so it's important to regularly replace air conditioner filters because they are designed to trap these pollutants.

An air purifier or better yet, a few plants, will work very well toward cleaning and filtering air to remove pollutants and irritants from your breathable air. Plants are nature’s air purifiers.

Spit Air Conditioner FAQs

Are there other options besides split air conditioner systems?

There are many other cooling options if you don't want to use a split air conditioner system. Window units are effective for cooling one room or one space in the home.

Geothermal and evaporative air conditioners are less common but also viable options. Split air conditioner systems are one of the most common ways to cool a home but not the only one.

There are several DIY options for creating cool air inside your home. You can even use a fan and some cold water to sort of improvise your own air conditioning system in a pinch.

Some of these DIY options are not viable long-term solutions, but they can buy you some time if you’re still considering your options and doing your research as far as air conditioners go.

Do split air conditioners require maintenance?

Both ductless mini split air conditioners and split air conditioners require regular maintenance and cleaning so they can operate at peak performance.

Maintain air conditioning systems regularly to keep them working at their best. Otherwise, the air conditioners will end up using more energy to work harder and this will raise your utility bill.

To clean your air conditioner, use a cloth dampened with plain water to clean the outside of the unit. Replace the filter and clean the inside and outside of the grate covering the filter.

Use a vacuum with a hose and cleaning attachment to remove dust from inside the unit. Spraying a can of air on dusty areas of the air conditioner works as well.

Perform this every four to six weeks. If you perform cleaning and maintenance regularly, it will only take a few minutes to accomplish all of these tasks.

If debris and dust build up, the process will take longer, and your air conditioner won't be operating as well as it should.

How much do split air conditioners cost?

Split air conditioner systems all function in basically the same way. However, there are many different styles and types and designs of spit air conditioner systems that make the price of such a system vary wildly.

Split air conditioners are also available in multiple sizes, which also affects the price.

Some split air conditioner systems will cost as little as $300 in small designs to thousands of dollars in larger, more extensive designs.

Remember that the price of the air conditioner extends beyond the system because you will also need pipes. If there is no ductwork installed, you will need to have this done and this can be a huge expense.

Can bad smells be coming from your air conditioner?

If you notice a weird smell coming from your air conditioner, you can’t blame the air outside your home because the system isn’t using outside air. Odors from the air conditioner are likely caused by odors in the home, perhaps from cooking food or pets.

However, dirt and debris, and even insects may also get inside the AC unit and could be the source of any foul odors. If you think the air from the AC smells funny, give the unit a thorough cleaning and see if this improves things.

Why is your split air conditioner making noise?

If you notice your AC system making loud or strange noises, this indicates there is a problem. Split air conditioners should not be making much of any noise other than an electrical humming, which is a standard sound from many appliances that you may not even notice.

A noise can be caused by loose parts inside the air conditioner or even broken or damaged parts in the unit. If you hear a strange or loud noise from the AC, consult with a professional to have the system checked.

How often should your ducts be cleaned?

If you have ducts in your home, it’s smart to have them serviced and cleaned out periodically. Dust, dirt, and cobwebs can accumulate inside ducts.

This junk can make it harder for air to travel through the home, which only makes your AC system work even harder and burn more energy. Dust and debris, and other stuff in the ducts can also deliver dust mites and other unpleasant additives into your breathing air.

That’s not great, obviously. It pays to have the ductwork in your home cleaned out every few years.

If someone inside the home has a high sensitivity to allergies or a compromised respiratory system due to asthma or some other problem, you might want to have the ducts cleaned out much more frequently.

Further Reading

3 DIY Air Conditioners

Air Conditioner Parts 101

How to Clean a Mini Split Air Conditioner

How to Identify a Leak in Your Central Air Conditioner

How to Remove Musty Smells from a Home Air Conditioner

How to Uninstall a Split Air Conditioner

How to Vent a Portable Air Conditioner

Using a Timer with an Air Conditioner

What Is a Propane Air Conditioner?