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:

Removing and fitting head restraints
First read and observe the introductory information and safety warnings Every seat is fitted with a head restraint. The centre rear head restraint is designed solely for use with the centre rear seat. This head restraint should therefore not be installed in any of the other positions. Remov ...

General Information
All components of the refrigerant circuit submitted for quality observation are always to be sealed (use original sealing caps of original part). To date, the original parts (compressor, reservoir, receiver/dryer, evaporator and co ...

Petrol
First read and observe the introductory information and safety warnings Petrol types Vehicles with a petrol engine must be run on unleaded petrol in compliance with the European standard EN 228 . Fuels with a maximum ethanol content of 10% (E10) can be used for refuelling. Petrol types ...