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:

Valve, Removing and Installing, Valve Explanations
1. Valve Body 1 - Valve body 2 - Valve Insert 3 - Valve cap The rubber valve for tubeless tires is designed to seal air-tight in the ...

A/C Compressor with A/C clutch
Caution Non-approved tools or materials such as leak sealing additives can cause damage or malfunctions in the system. Only use tools and materials approved by the manufactu ...

Changing bulbs in the front headlights (halogen H4)
Fig. 178 Rear view of the right-hand H4 headlight with plastic covers: ① dipped beam and main beam, ② turn signal and ③ side light Fig. 179 Rear view of the right-hand H4 headlight with rubber cover: ① dipped beam and main beam, ② turn signal and ③ side light First read and o ...