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:

4-Pin Heated Oxygen Sensor (HO2S), Removing and Installing
Note Do not repair the heated oxygen sensor wires. Repairing may result in malfunctions. Use the faulty sensor as a guide for installing all of the accompanying attachments, cable ties or marking bands. ...

Locking the front passenger door and rear doors manually
Fig. 156 In the end face of the right-hand door: manual lock covered by a rubber seal Fig. 157 Manually locking the vehicle with the vehicle key First read and observe the introductory information and safety warnings If the vehicle has a lock cylinder in the door handle of the front passe ...

Brake support systems
First read and observe the introductory information and safety warnings The brake support systems ESC, ABS, BAS, TCS and EDL only function when the engine is running. They make a considerable contribution to active driving safety. Electronic stabilisation programme (ESC) The ESC helps to ...