The wall-mounted split air conditioner compresses refrigerant (such as Freon) into a liquid state. Then use the heat absorption phenomenon when the liquid becomes gaseous under normal pressure for cooling. The air density is very small. You take a needle tube for injection. Fill a needle tube with air, block the air outlet with your hand, and push the needle tube to compress the air. With a needle, the gas can be compressed by a third of its volume.
The compressor sucks in the lower-pressure working fluid vapor from the evaporator, increases its pressure and sends it to the condenser, where it is condensed into a higher-pressure liquid. After being throttled by the throttle, it becomes a higher pressure liquid. After the low liquid, it is sent to the evaporator, where it absorbs heat and evaporates to become a lower pressure vapor, thereby completing the refrigeration cycle. For some applications, the gas must pass through a long tube (usually coiled into a solenoid) to allow the heat to be dissipated into the surrounding air. Thermally conductive metals such as copper are often used to transport vapor. In order to improve the efficiency of the condenser, fins are often added to the pipes to accelerate heat dissipation. The heat sink is a flat plate made of metal with good thermal conductivity.
