How Does an AC Work?

AC Today... Not Tomorrow! Read Our Reviews
How does an AC work

Do you ever wonder what exactly is happening inside that big metal box outside to pump cool air into your home?

Let’s take a peek into the inner workings of an air conditioning unit.

It’s all about cool … and heating

The core function of any air conditioner, whether a window unit or a giant central air system, is to remove heat from the air to lower the temperature. This is made possible thanks to a chemical called refrigerant, which flows in a loop within the unit to absorb and release heat.

Refrigerant is a specially formulated substance that changes from gas to liquid and back again very easily, allowing it to soak up heat and then let that heat dissipate. Inside your air conditioner are two coils filled with refrigerant lined up next to each other. The first coil is the evaporator coil, which is positioned right in the path of warm indoor air. When the refrigerant passes through this coil, it absorbs heat from the air and evaporates into a gas. Nice and chilly air then continues flowing into your room.

A never-ending cycle

From there, the gaseous refrigerant travels to the compressor where it gets squeezed into a smaller space. Compressing a gas raises its pressure as well as its temperature, so now we have hot pressurized refrigerant vapor. This hot gas gets piped over to the condenser coil located on the exterior of the AC unit. The refrigerant starts cooling off as it flows through the condenser and releases heat out into the outside air. By the time it reaches the end of the coil, the refrigerant has cooled down enough to condense back into a liquid.

But we can’t just pump cold liquid refrigerant back into the evaporator coil or it won’t be able to absorb as much heat. That’s why an expansion valve gets placed between the two coils—its job is to quickly lower the pressure of the liquid before it re-enters the evaporator. When the pressure drops, some of the liquid boils off into a gas, to soak up heat from your home’s air.

And thus the cooling cycle continues with refrigerant circulating between gas and liquid states, transporting heat out of your house. Pretty neat right?

It’s science!

At its core, any air conditioner leverages the magical heat-absorbing properties of refrigerant to provide crisp cool air on even the hottest days. The next time that familiar AC hum kicks in, you’ll know there’s some interesting science at work behind making your home a more comfortable place to chill out.

Have more questions or concerns about your system? Consult a pro from AC Today. Contact us online or give us a call at 941-751-2642.

» «
Committed To Excellence