defroster

Simple question but all my HVAC stuff is in boxes. With the A/C unit on the E9s being kinda an afterthought, is it possible to direct dehumidified A/C air to the defrosters or not?

I am looking for a supplier for the heater duct hose. Goes from the heater to the defroster nozzles. I have not been able to find a size that will fit at my local auto parts store. BMW says that it is unavailable and cannot tell me the size. Does anyone know where to source this? Or if not...