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How Does AC Refrigerant Work?

HVAC techniciansAn air conditioner takes the warm air in your home, and cools it down until you’re standing in a livable temperature. When it’s over 100 degrees Fahrenheit outside, you might want it to be about 30 degrees cooler inside. So you tell the air conditioner to change that, and cool your home. But how does it manage that? An air conditioner has a refrigerant in it that cools the air as it cycles back into your home, allowing you to live more comfortably inside. Most HVAC technicians come to your home to check on your refrigerant and the efficiency of your unit, so why not learn a bit about it? How does the AC refrigerant work? Read on to see how it works in just a few simple steps!


The first thing that happens in a refrigerant system is the compression of the refrigerant. The refrigerant, a chemical compound that changes easily from liquid to a gas. When the refrigerant is pushed into the compressor, it is a low pressure gas. The compressor pushes the gas molecules together, heating them up as the pressure raises. The compressor is the piece that keeps the refrigerant moving, as the low pressure is continuously pulled into the compressor to try and create some sort of equilibrium. It’s also one of the pieces to be most careful of, because the piping that leaves the compressor to continue on easily burns exposed flesh.


Once the refrigerant has been pressurized, the hot gas gets pumped into the condenser. This is the part of the unit that faces outside of your home. When you find the condenser, you’ll find that there’s hot hair usually being blown out of it. Would you believe that that heat is the heat that was in your home? The condenser has a few fans that blow across the pipes, cooling the gas. While the fans are cooling the gas, the pressure pulls the molecules tighter together, and the refrigerant condenses again into a liquid. The temperature drops to a more manageable level, causing the piping to shift from burning hot to very warm.  The liquid has most of the heat from your home burned off, and begins to move along to the next part of the unit.


In order to keep the refrigerant moving at a constant pace, and in order to gauge whether the air conditioning is continuing to cool the home, and whether the machine needs to continue the cooling process or simply maintain the current temperature. This metering device is the computer that controls the situation and keeps track of how things are working. If you’re having electrical problems, or your air conditioning doesn’t seem to respond to your programming, it might be because of this little device. Most air conditioning repair that requires electrical components focus in on this metering device When the hot refrigerant is pumped through the device, electrical information updates your air conditioning unit on how much work it has left to do.


Finally, the now lower pressure liquid encounters the evaporator. With a lower pressure, the refrigerant liquid is now ready to cool the home. Fans in the evaporator blow over the pipes holding the liquid, causing the pressure to change yet again. The chemical reacts by boiling through an endothermic reaction. Endothermic means that while it boils and evaporates into a gas again, the chemical absorbs the surrounding energy and heat, causing the temperature around it to drop. The fans continue blowing, causing the now chilled air to be pushed into the house. As more refrigerant is pumped into the evaporator, more warm air from the home is chilled through the endothermic reaction. The gas now holds that heat from your home, and is ready to take it outside, leaving you with a cooler house.

Back again, the refrigerant, now a warm low pressure gas, is pumped into the compressor, where it repeats the process over and over again. This chemical continues to react, changing from a high pressure gas to a high pressure liquid to a low pressure liquid to a low pressure gas and over again. It’s the circle of air conditioning, and at the end of it all, the metering device reads that the temperature in the home is now exactly what you asked for. It shuts off the system, allowing the refrigerant to settle back down and fall still.

An air conditioning system works hard to cool your home, and utilizes chemicals like carbon tetrachloride to help you manage every hot summer out there! If you’re interested in air conditioning units and the like, why not consider a career in HVAC service? There are plenty of amazing HVAC schools, like Valley College, that are able to teach you the twists and turns of the fascinating machines that regulate the temperature in your home. Get your certification in air conditioning repair, and ensure that every home has efficient air conditioning that keeps the cool air in and the warm air out!