Motor Vehicle Air Conditioning

Refrigerant gas is a consumable and requires regular replenishment. BUSTED!

The air conditioner is a closed system and should not require regular re-gassing.

All leaks manifest simultaneously. BUSTED!

Certain leaks will only present themselves under specific engine temperature or operating pressure. Typically a very small leak needs the system to be pressurised — occasionally extremely, as on very hot days — before it manifests. Furthermore, in the presence of a large leak, a tiny leak or weak spot will go undetected until the large leak is repaired.

Re-gassing the air conditioner will solve all problems. BUSTED!

Unless the refrigerant gas has been expressly vented through other mechanical repairs in the engine bay, the system has or had a leak and re-gassing will only be a temporary solution as the refrigerant will leak out again. There are a host of faults (electrical and mechanical) that could have occurred, far too many to discuss here. There are similarities between the mobile air conditioner system and the respiratory system of the human body. The mobile air conditioner is comprised of many parts — inside the cabin and in the engine bay. The belt-driven compressor is effectively the heart of the system. The evaporator or in-dash heat exchanger and the external heat exchanger or condenser are the significant other organs providing the cooling. All are connected by rubber hose and aluminium pipe. Experienced technicians analyse the symptoms of an under-performing system, much like medical doctors, and often open-heart (compressor) surgery is required. There are complex electrical systems regulating cabin temperature (climate control). Refrigerant gas, a liquid under pressure, evaporates under low pressure in the evaporator creating cooling, at which point heat is withdrawn from the cabin. The compressor then converts the vapour back into a liquid. This pressure creates much heat which is transferred to the atmosphere by the condenser, which is cooled by outside air, rammed in during driving and with the aid of a fan.

Once all visible leaks have been sealed, all will be fine indefinitely. BUSTED!

In older vehicles where there are a few leaks on initial inspection, it is very common that a few more present themselves as other weak areas are stressed under the full operating pressure of the recently sealed system.