You need to find out first if your Sharan has dual units or single, if it has a rear unit then it will be under the interior trim by n/s/r wheel arch. Under the bonnet there is a sticker under the giving quantity of refrigerant required.
I have a 99 durango and the amount of refrigerant needed for the single unit and double unit are listed under the hood on top of the radiator.
With utmost care :)
4.25 kg refrigerant required for 5 ton A/C
The only way to know if Freon (refrigerant) is needed in an air conditioner is to use tools and gauges to measure the performance of the system. The amount of refrigerant needed is based on the design of the entire system including the size of the unit, length and size of the refrigerant lines, temperatures, and type of refrigerant. Refrigerant is not consumed. If refrigerant is needed then the system was either not charged correctly when installed or there is a leak. There could be many reasons a system is not cooling. The correct answer to the question is: A skilled service technician will determined that the system was low on refrigerant by using pressure gauges, thermometers and other tools. There not function a home owner can perform to see if refrigerant is needed.
Under the drivers seat.
Check the Electronic Control Unit. I also had the same problem and it was the Unit( Computer box)
This depends on the unit. The tonnage just refers to cooling ability. A ton is equal to 12000 BTUs, not a weight of the unit, the coolant, etc.
Most Sunfires have a 'valve' on the A/C unit that you use to fill the unit with refrigerant. I say valve because it looks like a valve, but really its more of a nozzle. All vehicles from the mid to late 90's and on are forced by law to use only R-134a refrigerant. How much refrigerant your cars unit holds can be determined by finding the refrigerant charge label under your hood. It should be located near or above your A/C unit. The easiest way to ensure no mistakes or damages to your unit is to get a professional A/C fill. But the cheapest way is to buy a can of refrigerant (you can find these at most auto stores and even Wal-Mart) and follow the instructions given in the box. It will show you step by step how to add the refrigerant to your unit.
actually for the a/c have 2 units,one is the indoor unit and the other is the outdoor unit, and there will be a refrigerant gas flowing in between the two units (in the copper pipes) when the refrigerant comes to the indoor unit it comes with a cold format .and when the chilled refrigerant comes in the way of the hot air ,the refrigerant becomes hot and the air becomes cool. (there will be a blower inside the indoor unit to blow the air across the refrigerant pipe's and hot refrigerant now goes to the outdoor unit (i.e condenser), where the outside atmosphere air comes across the hot refrigerant so that the hot refrigerant becomes cool and the cold air becomes hot. so, the indoor unit is maintained in a cool temperature and the outside outdoor unit is maintained at a hotter temperature.
Is it a new or an old window unit? Assuming your looking to refill it I will assume it is an old window unit which most likely uses R-22 refrigerant. R-22 is an ozone depleting refrigerant that is being phased out but should be available until 2010. There should be a label on the window unit stating which refrigerant is used.
The refrigerant pressures are dependent on the type of refrigerant.
Depend on what is the Horse Power of the split unit. For Example 1Hp split unit can go up to 0.2 refrigerant ton maximum. http://weightlosstreatnow.com