ventilation,damp smell bungalow bedroom

[macram11]

My bungalow front bedroom smells of damp. The room has a double glazed front bay and a longer external single brick wall to the side(which doesn't recieve much heat/sunshine). The front bay windows run freely with condensation. The radiator is on an internal wall. Occasionally have to wipe black marks off the external wall and base of the bay. We would like to put fitted wardrobes along the external wall side of the room. Various suggestions include fixing battens to the wall, boarding with moisture resisting plasterboard and infilling the gap with insulating material,and moving the radiator to underneath the bay
windows. I could paint the external brickwork with that water repellant stuff. Can ventilation devices be fitted to existing double glazing. We have a dehumdifier.
At the moment we leave a window and door open for a bit of air circulation but this may not help with a fitted wardrobe. Any suggestions would be greatly appreciated

[Steve the gas]

Hi,

IMO, it needs at least 1 vent to the outside.