Do AC Units Use Outdoor Air? Indoor Air Quality Explained
You may wonder, “Do AC units use outdoor air?” A common misconception is that air conditioners (ACs) use outdoor air for cooling. However, this is not the case. They operate in a more complex yet efficient way to cool indoor spaces without using outdoor air.
Learning more about these systems will help you better understand how they function. Action Air Conditioning experts will provide a simple overview of how ACs work. Then, we will explain why ACs do not bring in outside air and how they ensure proper indoor air quality.
How Do Air Conditioners Work?
Air conditioners cool indoor air in a way you might not expect. The cooling process involves circulating refrigerant between indoor and outdoor units. There are 4 main components involved in providing your home with cold air.
Here’s a simplified breakdown of how ACs work:
Evaporator Coil (Indoor Unit)
ACs draw warm indoor air over the unit’s cold evaporator coil. The refrigerant inside the coil absorbs heat and humidity from the air, cooling it. Then, a blower fan sends the cooled air back into the home through ductwork and vents.
Compressor
Once the refrigerant is warm from absorbing indoor heat, it moves to the compressor. After, the compressor raises the refrigerant’s pressure and temperature and sends it to the condenser coil.
Condenser Coil (Outdoor Unit)
The hot, pressurized refrigerant travels to the outdoor condenser coil. The coil releases the absorbed heat into the outdoor air using the condenser fan.
Expansion Valve
The refrigerant passes through an expansion valve, reducing its pressure and temperature. After returning to a cold state, it’s ready to absorb more heat indoors.
These 4 components make up the refrigeration cycle. The process runs continuously, cycling on and off. Each cycle typically lasts between 15 to 20 mins.
So Why Don’t AC Units Use Outdoor Air?
Standard ACs DO NOT bring fresh air from outside. Instead, they circulate indoor air, removing heat from your living space.
Here are 3 reasons why AC systems don’t use outdoor air:
Better Humidity Control
Using outdoor air can raise indoor humidity. This makes it harder to feel comfortable inside. AC systems have better humidity control when using indoor air.
Air Quality
The outside air may bring in pollutants, like pollen or dust. Circulating indoor air helps prevent these contaminants from entering the home.
Energy Efficiency
Cooling the outdoor air would require significantly more energy, especially with high temperatures. It’s more energy efficient for ACs to cool indoor air than hot outdoor air.
Are There Any Exceptions?
Some HVAC systems have settings or vents that allow for the introduction of outdoor air. However, these features are not standard in most residential AC units.
Evaporative Coolers (Swamp Coolers):
Evaporative coolers draw in warm air over water-saturated pads. The water in those pads evaporates. This cools the air by 15 to 40 degrees Fahrenheit before it enters the home. Swamp coolers are refrigerant-free and are ideal for areas with low humidity.
Economizers:
Economizers use cool outdoor air to control temperatures instead of air compressors. They are add-ons to HVAC air handlers, drawing outdoor air and mixing it with return air from indoors. They usually work at night when the outside air is cooler. Professionals call this method free cooling. This option helps save energy on cooling costs.
How Do ACs Ensure Proper Indoor Air Quality Without Using Outdoor Air?
If it’s untrue that AC units use outdoor air, then how do they provide good indoor air quality? They provide proper air quality through the following:
Filtration
Blower fans in the indoor unit pull warm air through the filter. The air flows through the filter to remove contaminants. Then, the system cools the air. Filtration is essential for preventing pollutants from building up indoors.
Ventilation
AC systems continuously circulate air, which prevents stagnant air from sitting. Ventilation helps replace old air with clean, filtered air.
Regular Maintenance
Scheduling routine maintenance ensures your system operates efficiently. In return, this also helps preserve good indoor air quality.
Reach Out to Action Air Conditioning for Your Next AC Servicing!
With the answer to “Do AC units use outdoor air?” you can have clarity on how AC systems work. While most air conditioners cool using indoor air, others use outdoor air. Knowing how AC systems work helps you keep a healthy indoor space and enjoy a comfortable home.
To service your AC, contact Action Air Conditioning experts in Tampa Bay! Our experienced professionals can handle all of your AC needs. We can help you maximize indoor air quality and perform maintenance checks. Our technicians work with integrity. They provide reliable and trustworthy AC services to every customer.
Contact us today for a consultation or to schedule a FREE estimate!