Is a bigger compressor required for a T5/T6 rear air conditioner

[Jezza]

Hi there.
Has anyone had rear air conditioning reto-fitted by VW or aftermarket.
I need to know if a bigger compressor is required to handle to the extra load with from the factory or when retro-fitted.
My 16,000 km van's compressor has packed it in and I would like to retrofit a larger compressor now if a larger one is need for my future rear air conditioner.
Thanks

[Syncrotek]

On my 2005 2.5 TDI is the factory rear air cond. The compressor is the same as without rear air cond, I checked when I had a/c trouble one time. But the rear air -I think- comes with the "towing pack" with larger condenser, twin a/c condenser fans, etc.