Have noticed over the past few days that when the Climate Control comes on, there appears to be a slight whirring sound from behind the vents and a slight whooshing sound and the air coming out isn't that cold.

Anyone have any ideas?

Most likely the Air Con system needs leak tested and ( If OK) regassed.

 

Mine did this and it was due to low system pressure- If anyone near you has VCDS this would show up on there if the system pressure is low.

 

Steve