Anatomy of an Air Conditioner

It feels as though every summer is getting hotter and hotter. Sometimes the only reprieve we have is from the central air conditioner. And let us just say, even on warm days, we’re so thankful for AC. However, it’s a bit too easy to take the air conditioner for granted. While it’s easy to think of the AC as a metal box that lives outside, it’s actually much more complicated than that. Central air systems are made up of two parts. The furnace and the condenser. One lives inside, the other outside. Twice yearly tune-ups are so important because your furnace is used the entire year. Anatomy of an Air Conditioner: The Indoor Unit Without the furnace, you wouldn’t have cool air. It’s weird to say, but it’s the truth. Most homeowners correlate the winter weather with furnace use, but this piece of machinery plays a key role in the cool process. Thermostat Your thermostat is how you talk to your AC system. The thermostat can tell the system if you want hot or cold air, and what temperature you prefer. It’s safe to say that if your thermostat isn’t working well, the whole system will be off balance. Evaporator Coil Without the evaporator coil, you wouldn’t have cool air. But before we get into the nitty gritty, we need to talk about refrigerant. Refrigerant is a “working liquid,” and it’s the whole reason your home can cool. This liquid pulls heat and humidity from the air inside your home. Refrigerant lives in the outdoor condenser, but it is pumped from the condenser to the furnace to complete a cooling cycle. When pumped to the evaporator coil, the refrigerant gets so cold it turns into a gas. This gas facilitates a heat transfer process that pulls any heat and humidity from warm air. The gas absorbs the heat and then sends that heat back outside. Your HVAC system is constantly recycling air. It pulls in warm air that’s already inside your home. That air is pushed over the evaporator coil where the refrigerant cools it. Then, with the help of the blower, the now cool air can be distributed through your home. Expansion Valve While refrigerant itself is a wonderful thing, there is also such a thing as too much and too little. The expansion valve determines exactly how much refrigerant is released into the evaporator coil. This little device is located in the refrigerant line itself. The expansion valve allows the system to work at peak efficiency and won’t waste refrigerant. If the evaporator coil were to get too much refrigerant, that refrigerant would collect at the bottom of the input line and essentially be wasted. When the evaporator coil gets too little refrigerant, it’s forced to work twice as hard to produce the air needed to cool your home. Blower The air in your home and HVAC system needs some power to move, and this is where the blower comes in. The blower first pulls air to the HVAC system from inside your home. It then sends that air over the evaporator coil where the air is cooled. Then the blower pushes the cooled air into the ductwork where it is sent throughout your home. Blower Motor The blower needs something to keep it moving. This part is called the blower motor. It makes sure the blower fan is constantly rotating and keeping air in motion. Filter The filter is a small part of your system with two very big jobs. First, it keeps your HVAC system clean. It traps dirt and dust that can collect on your HVAC parts and hurt the system. The second job it does is making sure the air in your home is safe to breathe. Depending on the size and materials, an air filter can pull dust, dander, allergens, and even viral particles from the air. One of the most important parts of your entire HVAC system is the air filter. At Bell Brothers, we recommend changing your air filter twice per year. Once in the spring before AC season and once in the fall before furnace season. Routine maintenance for your air filter is crucial and we recommend changing it twice every year. Once in the spring before AC season and once in the fall before furnace season. Ductwork The air in your home needs to be told where to go, otherwise it would all just go to one area. Ducts, or ductwork, is a series of pliable metal tubes that move from your central air system to the vents you see on your walls. Air travels through the ducts so it can be evenly dispersed through different heating and cooling zones in your home. Damper The damper is air traffic control for your HVAC system. This little device makes sure the correct amount of air is sent to the correct duct. It keeps your home comfortable and evenly cooled. Supply and Return vents We talked about how the air in your home is recycled, we didn’t talk about how. This is all done through the supply and return vents. The supply vents essentially supply the home with treated air, while the return vents pull air from the home and return it to the HVAC system. Anatomy of an Air Conditioner: Outdoor Unit After all that, we’re ready to move outside to the condenser. The condenser is your outdoor unit and it has four critical parts that help release warm air outside your home. Condenser Coil The condenser coil is the opposite of the evaporator coil. Both deal with heat transfer, but in different ways. While the condenser coil pulls heat from ambient air, the condenser coil sends heat into the outdoor atmosphere. As refrigerant is pumped through the entire cooling system, it comes to the condenser—from the furnace—in a gas form. This gas form is hot and full of heat. The condenser retains a temperature cool enough to pull that heat from the refrigerant. That heat is transferred to the condenser coil and then released back into the wild. Fan The fan is what makes sure heat is sent away from the condenser and away from the home. As the condenser coil pulls heat from the refrigerant, the fan is ready to send it out into the atmosphere. The condenser’s fan is constantly moving heat away from the condenser. This helps ready the condenser to pull more heat from the refrigerant and helps keep the unit from overheating. Compressor We’ve explained that refrigerant moves from the furnace to the condenser, but we never touched on how. Refrigerant is able to move with the compressor. The compressor helps move refrigerant though the HVAC system and converts the refrigerant from hot to cold. Refrigerant is first sent to the evaporator coil. There it gets so cold that it pulls all the heat and humidity from ambient air. During this process, the refrigerant turns to a gas. The compressor pulls the refrigerant back to the condenser, compresses it back into a liquid and sends any heat it captured out through the condenser coil. Refrigerant Line The refrigerant needs somewhere to go! The refrigerant line directs it from the condenser, into the furnace, and back again. Know When It’s Time to Call for Help. Just because you know all the parts of the air conditioner unfortunately does not make you an expert. When something goes wrong, it’s very important to call a licensed HVAC technician. There are a few maintenance things you can do on your own, like changing an air filter, but when it’s time for the big lifts, call the experts at Moore Home Services.