Volkswagen Polo Service & Repair Manual: Charge Factor

Volkswagen Polo Service & Repair Manual / Refrrigerant R134a Servicing / A/C System, General Information / Refrigerant R134a Characteristics / Charge Factor

A vessel must have space for vapor as well as liquid. As the temperature rises, the liquid expands. The space filled with vapor decreases. At a certain point, there will only be liquid in the vessel. Beyond this, even a slight increase in temperature causes high pressure to build up in the vessel as the liquid tries to continue expanding even though there is not enough space for it. The forces that result are strong enough to rupture the vessel. To prevent a vessel from being overfilled, the regulations regarding compressed gasses specify how many kilograms of refrigerant that may be added to a vessel per liter of interior volume. The product of multiplying this charge factor by the internal volume of the vessel is the permissible capacity. The figure for refrigerant used in vehicles is 1.15 kg/liter.

Evidence of Leaks

External damage, for example, can cause a leak in the refrigerant circuit. The small quantity of refrigerant escaping from minor leaks can be detected for example using an electronic leak detector or by introducing a leak detection additive into the refrigerant circuit. Electronic leak detectors are capable of registering leaks with refrigerant losses of less than 5 g per year. Use leak detectors designed for the type of refrigerant. For example, a leak detector for R12 refrigerant will not work with R134a because R134a refrigerant has no chlorine atoms so the leak detector will not respond to it.

Water Content

Only very small amounts of water are soluble in liquid refrigerant. On the other hand, refrigerant vapor and water vapor mix in any ratio. Only ...

Refrigerant Oil

Refrigerant oil mixes with the refrigerant (about 20 - 40%, depending on compressor type and amount of refrigerant) and circulates constantly in the system, lubricati ...

Other materials:

A/C Service Station, Emptying
Caution If it is suspected that chemicals were added to the refrigerant circuit to seal leaks, do not connect the A/C service station and do not extract the refrigerant. ...

Pedals
Fig. 108 Pedals in vehicles with a manual gearbox: ① accelerator, ② brake pedal, ③ clutch pedal Fig. 109 Pedals in vehicles with an automatic gearbox: ① accelerator, ② brake pedal First read and observe the introductory information and safety warnings The operation and freedom ...

Switching the TCS on and off
Fig. 116 In the centre console: button for switching the TCS on and off manually First read and observe the introductory information and safety warnings The electronic stability control (ESC) only functions when the engine is running. It consists of ABS, EDL and TCS. When the engine is r ...