Why did high school classrooms replace air conditioners and heaters with system air conditioning?

High school classrooms have long been spacious and comfortable thanks to system air conditioning. System air conditioners have replaced traditional air conditioners and heaters, providing more efficient cooling and heating and better utilization of space, resulting in a better learning environment for students.

 

When you return to your high school classroom after a long time since graduation, it looks much different than you remember. The familiar space had undergone an unfamiliar transformation. Gone were the air conditioners behind the windows and the electric radiators in front of and behind the windows, replaced by system air conditioners like those found in corporate buildings. The air conditioner used to occupy one side of the classroom, which made the space feel small, but now the system air conditioner is recessed into the ceiling, which makes the classroom feel much larger. This also gives room for potted plants in the classroom and allows for larger lockers. Even the atmosphere of the classroom is cleaner and more sophisticated than before.
Recently, the air conditioners, heaters, and stoves that used to cool and heat the classrooms have been replaced with system air conditioning. In the past, I remember that air conditioners and heaters were not often turned on due to the school budget. Nevertheless, schools are now replacing these appliances at great expense. Why is this?
To answer this question, we first need to understand how system air conditioners are built and how they work. System air conditioners are based on the same refrigeration unit that makes your refrigerator or air conditioner cool. It consists of a compressor, condenser, expansion valve, and evaporator. It also contains a substance called refrigerant, which flows continuously in one direction. As it turns from liquid to gas and back again, it moves heat from one side to the other.
To better understand how a chiller works, let’s compare molecules to people. The refrigerant can be thought of as a group of people. The compressor compresses the gaseous refrigerant to create a high pressure and temperature, which is like pushing a group of people who are far apart and forcing them closer together, causing them to try to push each other further apart and generate heat. The refrigerant at high pressure and temperature then passes through the condenser, the part where it meets the air. As it passes through the condenser, the refrigerant cools down and becomes a liquid, just as people who are hot and furious cool down by taking out their anger on those around them who are not. Next, as it passes through the expansion valve, the refrigerant reduces in pressure and temperature. It’s like people pushing against each other in a small space, but when they move to a larger space, they push less and get less heat. The refrigerant then passes through the evaporator, which is where it meets the air again, but unlike in the condenser, the temperature rises and it turns into a gas. You can think of it as getting hotter and hotter, because this time they’re taking out their anger on people who are more angry than they are. The refrigerant then flows back to the compressor and the process is repeated.
This refrigeration principle is how air conditioners work, but interestingly enough, you can also use this process in reverse to heat your home. All you have to do is change the position of the condenser and evaporator to make the room hotter and the outside cooler. Since the condenser and evaporator are usually similar in shape, system air conditioners are made with one additional unit, so that the one in the room can be used as a condenser and then as an evaporator. That’s why you don’t need an air conditioner and a heater at the same time, and you can cool and heat with a system air conditioner.
Also, compared to the refrigerant running around in circles as mentioned above, all we do is push the refrigerant slightly in the compressor. Even with that small amount of pressure, the refrigerant moves heat, and the amount of heat it moves in a single turn is about four times more than what we push. This means it’s very efficient at heating or cooling the air in a room quickly. So, for the same amount of money, schools can cool with similar performance to traditional air conditioners in the summer and heat about four times more efficiently than other heating appliances in the winter.
In other words, the system air conditioner is able to cool and heat at the same time and is so efficient that it replaces air conditioners and heating units. As a result, in classrooms with system air conditioners, the space previously occupied by air conditioners and heating units is now used to house lockers for students or potted plants to alleviate claustrophobia. In addition, the classroom’s cooling and heating time has increased, providing a more comfortable environment. The downside is that it uses electricity, which could limit cooling and heating in the event of a power crisis. Despite these pros and cons, it’s clear that the installation of system air conditioning is a change to provide a better learning environment for students. This shows that the school is making an effort to accommodate students, which suggests that an improved educational environment can be directly related to student academic performance.