I'm renting an appartment in a small appartment block, which got very hot last summer, and very moist in winter when hanging our laundry. The obvious solution would be to place a protable airco unit,but the problem is that we live near a very busy road, so opening a window even slightly makes conversation quite difficult.
However, there is an air vent, that is basically a hole with a vent cover through the 'inside' wall; when the vent is opened, there is a noticeable airflow of outside air entering the room, suggesting that there are also some holes in the 'outside' wall (visual inspection seems to confirm this, although it's difficult to see).
I was wondering if I could vent the airco in that hole, or whether venting in the wall cavity is a Bad Idea ©.