Is it possible to use metal ventilation ducts for through-the-wall applications (supply air channels)?
The reason for my question is that my ventilation guys are building a custom construction with supply air channels that include a cassette that will open and close itself.
A friend of mine (a carpenter) warned me about metal/condensation and suggested that plastic pipes might be recommended.
I've heard that the biggest risk is during warm summer days when the house is cooler than the outside. I know absolutely nothing about this and would appreciate all thoughts and considerations. I don't want to build something into the walls that creates problems.