My feeling is the Mould is due to condensation and the question is whether to seal the vent or not as I feel this is the source of damp air getting in and the air being cool the reason the condensation is happening. Unfortune tly the kitchen is not the warmest room in the house heated by a Myson kick board heater, neither is it well ventilated relying on an open window when cooking.
The improvement to the heating and ventilation of the kitchen is awaiting t he replacement of the kitchen sometime in the next two years. In the meanti me I need a solution to the Mould problem, I have bought a dehumidifier to help with RH. What is the consensus of the group regards sealing the vent? I know that good ventilation is the key to removing damp air thus controlli ng condensation but this vent seems to be the source of the cold/damp air a nd the cooling the reason condensation is occuring.