Your commercial A/C compressors are tasked with the important job of converting low-pressure refrigerant to high-pressure refrigerant within your closed HVAC systems. It is this exchange of pressures and temperatures that allows the refrigerant to take the heat out of your indoor air and move it outside. This process occurs over several stages, but the compressor is central to these efforts.
How Refrigerant Works
Before we can fully explain how your commercial HVAC compressor works, you first need to understand the role that refrigerant plays in your HVAC system. Contrary to popular thought, the refrigerant itself does not actually cool your air just by itself. It actually absorbs heat from the air and takes it away. This process is known as heat transfer. Heat transfer occurs any time warm air comes into contact with a cooler surface. In this case, the coils that contain your refrigerant are cooler than the air around them, so the coils absorb that heat from the air. Then a fan blows the cooled air back into your home. It is important to remember that your HVAC system is not actually producing new cool air, it is simply pulling heat out of the existing air in your home.
Where Your Compressor Comes In
In order for the rest of the system to work, your compressor has to come into play. The trick is to get the temperature of your refrigerant higher than the outside air so that the outside air will then absorb the heat and pull it away to cool the refrigerant back down. Just absorbing the heat from inside your business is not sufficient to raise the temperature of the refrigerant above the outside air temperature. If it was, it would mean that your office building is routinely hotter than the outdoor air temperature during the summer, which would be sweltering.
The easiest way to raise the temperature of the refrigerant is to compress it rapidly with your commercial HVAC compressor. When this happens, the refrigerant that is already warmed by your inside air is forced through a compression chamber which increases the temperature and pressure together. This highly compressed refrigerant becomes a gas that flows out the discharge line where it meets the outside air. Again, a fan blows outside air across the lines, which instantly absorbs the heat from the lines and cools the refrigerant back down to a liquid state. Once the refrigerant is a liquid once more, it flows back inside to pick up heat from your indoor air, and the cycle begins again.
Now that you see the basic function that your compressor plays in your commercial HVAC system, you will also want to learn exactly how the compressor does its job. This largely depends on the type of commercial compressor that you have. All compressors have a low-pressure inlet and a high-pressure discharge line. In some compressors, the air flows into a compression chamber with a piston that is similar to a car engine, which mashes the air down into a smaller space and sends it out a valve. However, more efficient options like scroll and screw type compressors provide more consistent compression by forcing air through a series of smaller and smaller spaces and continually pushing air through. These compressor types tend to be more compact but slightly more expensive on the front end. However, for commercial HVAC purposes, they offer the best cost of operating over the long term.
If your HVAC compressor is not getting the job done right, make sure you call on Compressors Unlimited to find high quality HVAC compressors for your commercial building. It is easy to see how important the compressor is in your system's operation, so if you feel like your compressor isn't holding up, a replacement may be the best solution.