It might seem like magic. After all, how could your air conditioner blow cold, chilled air throughout your house even when it’s 100℉ outside? Are you wondering how air conditioning works? The real answer might be a little complex, but it certainly isn’t magic—it’s science!
In today’s blog post, the HVAC experts at Air Works Heating & Air explain how your home’s central AC system creates cool air on a hot summer day. We’ll cover the various aspects of the refrigeration cycle, explain what each piece of the equipment is doing, and shed some light on an interesting piece of engineering that many people take for granted.
To understand how air conditioning works, first you need to know about the major parts and equipment these systems use.
The refrigeration cycle is the science behind your home’s central air conditioning system. Possibly the most common misconception with air conditioning is that it “adds cold” to the inside of your home. Not true! Heat is what’s exchanged, not cold. This means that air conditioning “removes hot” by transferring the excess heat from your inside air out to be released into the outside air. Exactly how this process works is a little technical, but it can be explained using fairly simple terms.
Let’s explore the four main stages of the refrigeration cycle. Please note that the order listed below is not important, because the cycle is continuous rather than having a distinct start or end. It’s also important to note that this is a slightly simplified explanation that touches on the main points and leaves out some of the details.
As your air conditioner’s refrigerant flows away from the blower unit (evaporator) and outside toward your condenser unit, it was just used to chill the hot air inside your house. That means it’s carrying the excess heat you’re trying to remove from your home. At this point, the refrigerant is a vapor (gas) at relatively low temperature and low pressure.
Once the refrigerant enters your outdoor condenser unit, it runs into a powerful electric compressor that forces pressure into the vapor. That squeezing compressive force causes the temperature of the refrigerant to increase substantially, far higher than the outside air even on the hottest summer day. The high-temperature, high-pressure vapor then enters the condenser coil, which works much like your car’s radiator. A fan blows ambient outside air through the condenser coil, releasing all that excess heat into the air and away from your home.
After releasing its excess heat in the condenser, the refrigerant becomes a high-pressure, high-temperature liquid. This liquid is pumped back into your home and toward an expansion valve, which removes the pressure and causes the liquid refrigerant’s temperature to plummet.
After the expansion valve, the low-temperature, low-pressure liquid refrigerant is forced into your blower unit, where it enters the evaporator coil and converts to an ultra-cold vapor as it expands. The blower fan then forces warm inside air through the evaporator coil, where the ultra-cold vaporized refrigerant chills it, and the cycle starts again.
In basic terms, your home’s air conditioner forces the excess heat inside your house into a refrigerant that carries this heat outside and releases it into the outside air. The science of matter as it changes phases between a liquid and a gas, known as Boyle’s Law, makes it all possible. It enables us to keep the refrigerant cold enough inside to pick up excess indoor heat (chilling your air) and then getting the refrigerant hot enough to release that heat into the hot outside air.
If the process is still mysterious to you, don’t worry! The experts at Air Works Heating & Air have all the knowledge, training, and experience needed to inspect, maintain, and repair your air conditioning no matter what the issue. We have you covered! Just call us at (919) 528-4333 or contact us today if you have any questions or need your HVAC system serviced.