Question

Why must recycled refrigerant be checked for air?

Answer 1

Recycled refrigerant must be checked for air to ensure the efficiency and performance of cooling systems while avoiding potential damage like corrosion or blockages. Air increases system pressures and temperatures, leading to a higher cost of operation and decreased equipment lifespan.

Step-by-step explanation:

Recycled refrigerant must be checked for air because the presence of air can decrease the efficiency, performance, and potentially harm the system they are used in. Systems like refrigerators, air conditioners, and heat pumps operate on thermodynamic cycles where the efficiency is critically dependent on the temperature difference (T₁ and T₏). When air, which is a non-condensable gas, is mixed with the refrigerant, it leads to increased pressures and temperatures within the system. This can result in a larger temperature difference than designed for, thus reducing the system's coefficient of performance (COP). Moreover, air contains moisture which can introduce water into the system, potentially causing ice blockages or corrosion, and can reduce the refrigerant's capability to absorb and transfer heat effectively. If the recycled refrigerant is not checked and cleared of air, the operation cost can increase, and the lifespan of the equipment can be significantly reduced.

Answer 2

Air is considered a contamination in an A/C system. This is because it is a not a condensable gas.
This means that the type of pressure that the A/C can reach is not sufficient o condense the air from gas to liquid.
As a result, air will only be occupying space and displacing the refrigerant which will lead to a poor performance of the whole system and can even lead to total failure of the system.
This poor performance can be in terms of:
1- evaporator freeze-up
2- noise
3- reduced cooling performance
4- higher discharge pressure