How Does AC Work?
- / How Does AC Work?
Air conditioners are essential for a modern home, especially if you live in a hot climate like Southwest Florida. Although we’re reliant on air conditioners to enjoy a cool and comfortable home, most people don’t understand how they actually work.
Air conditioners cool your home using a brilliant combination of mechanics and the power of thermal exchange to extract heat from inside a home and release it outside. Let’s explain the basics of how an AC works so you can understand why it’s important to keep your AC well-maintained, or why you should install one at your home.
General Premise on How AC Works
Air conditioners are used to cool the air temperature in your home, reduce humidity, and provide your home with better air quality. ACs do this through a process that happens simultaneously on the inside and outside of your home.
- Indoors: Warm air in your home is drawn into the HVAC system and passed over evaporator coils. These coils use a cold refrigerant to remove heat from the air inside your home. That refrigerant is cycled through the HVAC system where the heat is moved outside to be released. Then the air that has been cooled by through the evaporative process gets cycled back into your home.
- Outdoors: The refrigerant that’s used to cool the air is moved outside where it’s circulated through metal fins to disperse the heat. Then the refrigerant is cycled back into the system to be used again.
The Basics of How Central AC Works
Most homes in the United States (and here in Southwest Florida) use a central air conditioning system. Central ACs transfer cool air throughout your entire home, using refrigerant as a key component.
Heat is absorbed whenever a liquid is converted to a gas, and refrigeration uses this scientific principle to its advantage. Central ACs pass chemicals (known as “refrigerants” through the HVAC system where they come into contact with the warm air being drawn from your home and expand into gas. When the refrigerants expand, they absorb the heat from the warm air and cool it.
Central ACs also remove humidity by collecting condensation from the warm air that’s drawn from your home. The condensation is safely drained from the AC unit.
AC Unit Parts
It’s easier to understand how air conditioners work when you know what the main components are and what they do.
An air conditioner’s main parts are the:
- Evaporator: The evaporator contains coils that cool the air passing through the system, and it also holds the refrigerant for the coils. As the warm air passes over the coils, it makes contact with the refrigerant and causes the refrigerant to expand into gas. The expansion removes heat from the air, and also pushes the gas into the compressor.
- Compressor: The compressor increases the pressure and temperature of the gas to concentrate the heat and make it easier to remove from the system.
- Condenser: The condenser turns the hot, gaseous refrigerant back into a liquid, which expels heat from the refrigerant. The heat is released from the coils where it is blown away from the system by a fan, and the cool refrigerant is transferred back into the AC system to be used again.
- Expansion Valve: The expansion valve regulates the pressure of the refrigerant being passed to the evaporator.
The inside part of the AC unit contains the evaporator and a fan that circulates warm air over the coils.
The outside part of the AC unit contains the compressor and condenser.
What Are Refrigerants?
The refrigerant is the most important part of the AC system, outside of the main components. It’s a chemical that’s used to absorb heat from the warm air in your home.
Your AC expands and condenses refrigerant to remove heat from your home, leveraging the scientific principle called phase conversion. This principle results in:
- Heat being absorbed when a liquid becomes a gas
- Heat being released when a gas becomes a liquid.
An AC system basically turns liquid refrigerant into gas to remove heat from the air. The gas refrigerant is transferred outdoors, where it’s turned back into a liquid and the heat is expelled outside of your home.
Central air conditioners run this cycle continuously until your home has cooled to the desired temperature.
The Refrigeration Cycle Process
Here’s a quick step-by-step that explains how refrigerant is used to cool your home:
- Heat is Absorbed by Liquid Refrigerant: Warm air is pulled into the AC system where it’s passed over coils that contain cool, liquid refrigerant. The warm air heats up the refrigerant and causes it to expand into a gas, which simultaneously absorbs heat from the air. The air cools as it passes over these coils and is then transferred back into your home.
- Compressor Makes the Gas Hotter: The refrigerant gas expands into the compressor. The compressor increases the pressure of the gas, making it hotter and easier to remove from the system.
- Refrigerant is Cooled: The refrigerant gas is moved outside into the condenser. The condenser cools the gas rapidly and causes it to turn back into liquid refrigerant.
- Heat is Removed Outside: As the refrigerant turns back into a liquid, the released heat is blown away by a fan.
Refrigerant Cycled Back to Evaporator: Once the refrigerant has been turned back into a liquid and cooled down, it’s returned to the evaporator for another cycle.
What is Central Air?
Central Air is the most common type of HVAC system in the United States. It’s also known as a “split system” because it uses both indoor and outdoor units.
Central air conditioning usually includes the following design mechanisms:
- Indoor unit that collects warm air from your home and cools it
- Outdoor unit that expels heat outside of your home
- Thermostat for controlling the temperatures in your home
- Air ducts to transfer air to and from the AC unit
- Coils made of copper tubing that circulate refrigerant
- Valves that regulate the refrigerant pressure
How Air Conditioning Works in Detail
It should be easier to understand how air conditioners work now that you’ve learned about the refrigerant process.
Here’s what the other AC parts do:
- Thermostat: The thermostat allows you to set the desired temperature for your home. The thermostat will start the cooling process when it detects that the temperature in your home has exceeded what you set on the thermostat.
- Circuitry: Electrical wiring allows your thermostat to communicate with the rest of the AC system to start, end, and monitor the cooling process.
- Fans: Your AC system includes several fans that circulate air through the system. The indoor fan pulls warm air from your home and blows it to the evaporator, while also blowing the cooled air back into your home. The outdoor fan blows air over the coils containing the heated refrigerant to cool the refrigerant before cycling it back inside.
- Filters: Air filters clean the air that’s moving through the system by collecting dirt, smoke, allergens, and other contaminants.
Types of AC Units
Not all air conditioners are the same. There are different types of AC units that function a little differently from each other.
The split system (also known as a “central air conditioning system”) uses both an indoor and outdoor unit to cool your home. This is the most common type of AC system in the United States. You’ve probably noticed the “big box” on the outside of a home, which is the outdoor unit. The indoor unit can be a little trickier to find, but it’s usually located in the garage, basement, or utility closet. Split systems are usually the quietest and most efficient type of AC system with the longest lifespans (so long as they receive regular maintenance).
Packaged air systems work in mostly the same way as split systems, but they combine the outdoor and indoor unit into a single unit. These systems are often used on properties that have little space for separate units and are often placed on the rooftop of a property.
Central air systems use a single indoor cooling unit to cool and distribute air throughout your entire home. Ductless air systems incorporate individual cooling units in each of the rooms in your home. This allows you to set individual temperatures for all of your rooms (for example, you can keep your bedroom warmer than your living room). There’s still a single outdoor unit that all of the indoor units must be connected to, which usually makes the installation more labor-intensive and expensive.
Benefits of AC Units
There are so many benefits to AC units, which is why they’ve become an essential component of any home, especially in Southwest Florida.
- Better Comfort: Air conditioners are the most effective way to keep your home cool and comfortable, especially in the hot summer months. They’re far more effective at cooling than ceiling fans or pedestal fans.
- Improved Air Quality: Air conditioners filter out air pollutants, including dirt, dust, allergens, smoke, and small pests. You’ll enjoy better air quality in your home and be at lesser risk of asthma attacks or having irritated lungs and sinuses.
- Better for Your Health: In places where it gets extremely hot, such as Florida, you may be at greater risk of dehydration or heat stroke without having AC to cool your home. You’ll also get better sleep at night when you’re not hot and sweating all night long, which has a myriad of additional health benefit.
- Higher Security: Many people who don’t have an air conditioner will open up their windows to try and cool their home. Open windows could put you and your family at greater risk of theft or home invasion.
- Quieter Home: Open windows also allow unwanted noise to disturb your home. You can close your windows when you have an AC system and give your home more quiet and privacy.
If You Need an AC Installed, Call Hurricane Air Today!
Hurricane Air has a team of licensed and trained HVAC specialists ready to assist you with a new AC unit purchase. We will inspect your home to determine the best air conditioning system for your home’s needs. If you are in need of a new air conditioner or any air conditioner services, Hurricane Air is ready to help. Call today to speak with a specialist and schedule an appointment!