Do Air Conditioners Bring in Fresh Air From Outside? Air Quality Tips

Air Conditioning, Indoor Air Quality

People always say, “Nothing beats the fresh air.” That is until your under the blistering sun and sweating buckets and your only escape is inside your air-conditioned home. You feel so good indoors but you miss that fresh air so you might wonder, “Do air conditioners bring in fresh air from outside and into my home?”

The quick answer is, no. Your air conditioner does not bring fresh air into your home from outside. The performance of your AC depends on the airtightness of your home. This helps the cooling process to take place a lot quicker and more efficiently.

do air conditioners bring in fresh air from outside

If you need more details than the quick answer provided, then read on so you can have a “fresh” take on the matter.

The High Demand for Air Conditioning

As much as we all want to be close to nature by throwing our windows open, the sight and smell of grass and the surrounding trees, and the cool mild breeze blowing to our faces, we cannot all afford it. We are not just talking about affording it with money, but with all the modernization around us, the growing air pollution, and the threat of global warming made it is difficult to gain access to pure air.

More and more people are turning to air conditioners to keep their homes cool and comfortable even in the hottest of summers and keep the high level of humidity out of the way. 

If you are one of these people who made the switch from natural open air to the modern recycled air offered by air conditioners, there is no reason to feel bad. 

Let’s look into the reasons why deciding to separate the indoor air from outside through your AC is just as good, if not better, for your family.

Bloomberg Media, a very well-known and respectable leader in business and financial data, news, and insight, published an article discussing the results of the Residential Energy Consumption Survey conducted in 2015.

The results of the study revealed that almost 90% of American families have air conditioning of some type during that year. A significant percentage of 61.6% have central air conditioning systems, 26% have a window or wall-type air conditioners, and only 12.5% do not have AC in their houses.

The article commented that homes that are built in the last 20 years are specifically made to have an air conditioner installed in them. It might be impossible to buy a new place to live without an AC in it.

Even though purchasing and installing an AC is expensive, it is not only the wealthy that decides to have an air conditioner at home. The US government’s research in 2015 shows that even in households that are earning below $40,000 and are considered low-income, 50% of them still own central air, and 25% to 30% have a window or wall-type unit.

Why such high demand for the costly and processed air offered by AC when fresh air is free?

Bloomberg made the most poignant answer to it by saying, “AC is…a response to a warming planet.”

The Climate Institute supports this statement when it said that demand for air conditioning and refrigeration increases as the Earth’s temperature rises. The institute equates staying cool to staying safe as our climate keeps on changing and because “dangerous heat waves may become more prevalent.”

Not everyone may be aware of these studies’ conclusions about why we need air conditioners so much. But we do know that air cooling is not just a sense of temperature as felt by our skin, but also brings the right level of humidity, indoor air quality, and acoustics. We put prime importance on the temperature of room air as it provides an environment of comfort and difference can be felt versus a non-air conditioned room.

How Air Conditioners Work

Not because you have an air conditioning system at home, in your office, and in your car already means you already understand how air conditioners work. Most people only care about air conditioner brands and how the AC makes summer days bearable. Many don’t bother getting into the nitty gritty details of the cooling process.

If you really want to know, we offer a quite simple explanation of how an air conditioning unit works in this previous article. This will also rebuff the greatest misconception of how the unit operates.

But for this blog, let us discuss how popular types of cooling units in America function. 

Central or Split Air Conditioners

As cited in the statistics above, the majority of Americans have central air conditioners in their residences and workplaces. This is the most sought-after type of cooling system because it is ideal for whole-home temperature conditioning and dehumidification.

The main element of a central unit is the ductwork which serves as the passages for hot air intake, then later, the delivery system for the cool and processed air. These ducts and vents are typically hidden away in the ceiling, floors, attics, and basements.

Central ACs also have indoor and outside components. The warm air is sucked in through an air handler fan inside the indoor part, travels through the duct system, and passes over the evaporator coil. The refrigerant in the coil takes in the heat from the drawn air.

The refrigerant that carries the heat moves to the outdoor unit called the condenser. This is where the heat is expelled to mix with the outside air so the cooling compound is back again to being cold to repeat the entire cooling process.

Mini-Split Air Conditioners

Similar to central cooling systems, mini-split air conditioners have indoor and outside elements connected by a line set made out of copper. 

The difference between these two types is the absence of ductwork on mini-splits. Because of this, mini-split units cannot cool the entire residence with just a singular installed unit. It can only draw the heated air from close range and blow cool air in one room or area.

If you decide to cool multiple rooms in your house, you should install one unit in each room. Since it does not require ductwork, the installation is a little easier but the cost of the equipment tends to be higher. 

Window Air Conditioner

As its name suggests, a window air conditioner hangs outside a house or office window, typically secured by metal boxes. This type of unit is ideal for small apartments or cooling only one room. Because it does not have ducts to rely on for airflow, it can only remove heat from its immediate space. The chilled air cannot travel through the other parts of your home.

Because of their simple nature, these units are low-cost and easy to install. Still, although they are literally on the opening of a wall, they do not bring in oxygenated air. Instead, the heat from the air indoors is thrown outside.

Does Your AC Bring Fresh Air from Outside?

There is no denying that fresh air is vital in keeping our bodies healthy. It helps to improve our digestion, blood pressure, and heart rate, stronger immune system, and lower chances of obesity. Fresh, natural air is said to be responsible for a healthier respiratory system and regular release of toxins from our body.

The HuffPost [formerly Huffington Post], the online source of the latest headlines, news stories, and opinions on politics, entertainment, and other subjects related to the findings of a study connecting fresh air to vitality. It shows that “spending time in the fresh air, surrounded by nature, increases energy in 90 percent of people.”

This claim is supported by Vitality Medical, a preferred provider of quality medical supplies and health and wellness products, as it lists all the critical roles oxygen fulfills. This includes producing different proteins necessary for building new and replacement cells, reinforcing our immune system to fight bacteria, and fueling our body’s defenses against viruses and other harmful intruders.

Oxygen is so important that without it for ten minutes, severe neurological damage will occur. In 15 minutes of being deprived of oxygen, most people can no longer regain their cognitive functions according to the University of California, Santa Barbara (UCSB) Science Line.

But let us be clear about one thing: Residential air cooling systems do not bring in natural or “fresh” air from outside. 

As fresh as you might feel with a fully-functioning AC running inside your home, the air that it releases to your living space is the exact air it pulled in. A standard air conditioner draws the warm air indoors, cools it through the coils, and removes the heat and humidity in the process. Once the heat is expelled outdoors, the AC blows back the SAME air to the room but only cooler. Hence the reason for calling it “recycled” or processed air.

Do not mistake that the outdoor component of your AC is mixing the outside air with that of the indoors. If it does, allergens that you so desperately want to get rid of will invade your home.

The Value of Air Tightness

For your AC to do its job properly, the rooms have to be airtight so that no amount of outside air can creep in. This way, the air conditioning process will run smoothly and infiltration from outdoor air will not put an unnecessary burden on the unit. It will also be economical for you because the AC will not be working too hard to cool the room and will consume less energy.

Since the air conditioner commonly operates in a tightly sealed room, it is crucial then to ask, “Does my AC depletes or add to the amount of oxygen in my house?”

The answer is neither. Only the existing air in the living space is pulled in by the AC; it will be cooled by the coils inside the unit, the excess moisture will be removed, and the heat will be exhausted outside. The system is not built to either increase or lessen the level of oxygen in the room.

The Hazards of Too Much Air Sealing

A more serious threat worth looking into is the two invisible gases that can harm our bodies if we are trapped in an airtight room with it: carbon monoxide (CO) and carbon dioxide (CO2).

The Mayo Clinic describes carbon monoxide as, a “colorless, odorless, tasteless gas produced by burning gasoline, wood, propane, charcoal, or other fuel.” The nonprofit organization and also an academic medical center warn that CO can accumulate to harmful levels especially if devices and appliances are not properly ventilated. 

This is especially hazardous “in a tightly sealed or enclosed space,” the Mayo Clinic continues, as it can lead to carbon monoxide poisoning. When that happens, CO builds up in your bloodstream and replaces the oxygen in your red blood cells, which then leads to tissue damage or death.

Meanwhile, carbon dioxide is exhaled by every living human being and animal and is a part of a natural cycle. However, an average person breathes out around 500 liters or around 1 kilogram of CO2. Imagine if a room is regularly occupied by five or more people! 

The website Occupational Health and Safety informs that “moderate to high levels of carbon dioxide can cause headaches and fatigue, and higher concentrations can produce nausea, dizziness, and vomiting. Loss of consciousness can occur at extremely high concentrations.”

Other objectionable gases are also in danger of accumulating in an airtight room with modern decoration materials and adhesives.

Stay Cool But Safe

You will be relieved to know that while your air conditioners do not bring in fresh air into your home, they also DO NOT produce carbon monoxide or carbon dioxide. 

But other appliances in your residence can contribute to CO and CO2 buildup, particularly those that are poorly maintained. These are your heater, furnace, stove, water heater, or other fuel-burning appliances.

How do you protect yourself and your family from these dangerous health risks that cannot be seen by the naked eye? 

There are two major ways to stop your loved ones from suffocating inside your home:

1. Install carbon monoxide detectors and air quality sensors. Because CO and CO2 are not easily sensed by our body until it is too late, these devices are extremely helpful in giving us a warning if there is too much in the air. The Mayo Clinic wisely suggests positioning one in the hallway near each bedroom or other sleeping areas in your house to prevent your family from being poisoned. If the alarm sounds, leave the house and call 911 or the fire department.

Most designs are battery-operated so they can continue to detect and set off an alarm even during power outages. Also, be mindful when the CO monitor has to be replaced. Some brands have an end-of-life signal chirp so you will be reminded when to go for a new one.

2. Get help from a professional HVAC technician. Although we are certain that your air conditioner cannot cause carbon monoxide poisoning, your heating equipment can sneak up on you and produce that dreaded CO and CO2. The HVAC guy you should trust can detect leaks because of improper installation and repairs that could have originated from low-cost but hasty contractors. An annual checkup will not hurt your budget and could be very well worth it to prevent any poisoning from carbon monoxide and other hazardous gases. A proper cleanup of the air filter can also be performed per year to avoid being attacked by another common enemy, allergy triggers.

1 thought on “Do Air Conditioners Bring in Fresh Air From Outside? Air Quality Tips”

  1. I appreciate that you covered many air conditioner types. As you mentioned, this featured window air conditioning, which is great for small flats because it doesn’t rely on ductwork for ventilation. Installing one would be beneficial for my daughter because she would be moving into her own apartment. I’ll definitely let her know about this and look into HVAC system installation firms that could be able to help her.


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