Why is the air conditioning pipe outside the car very cold but not cold inside?

[OliviaLee]

It may be due to insufficient refrigerant or a dirty air filter. Below are the relevant explanations: 1. Refrigerant: Refrigerant, also known as coolant or freon, is the medium substance used in various heat engines to facilitate energy conversion. 2. Function of the air filter: It ensures the air filter fits tightly against the housing, preventing unfiltered air from entering the cabin; it separates solid impurities such as dust, pollen, and abrasive particles from the air; it adsorbs moisture, soot, ozone, odors, carbon oxides, SO2, CO2, etc., from the air; it prevents car windows from fogging up, ensuring clear visibility and safe driving for passengers; it provides fresh air for passengers, preventing them from inhaling harmful gases and ensuring driving safety; it effectively sterilizes and deodorizes.