Ventilation in porch - condensation

[king.inter]

I have a porch on the front of my house which has at some point had a pvc door fitted to the front of the porch, effectively making a small room between the pvc front door and the original wooden front door. This measures approx 8ft high x 3 1/2ft wide x 6ft long. I am getting some damp on the wall towards the bottom which goes away if I leave the pvc door open, but I can't keep doing that. What I want to know is if I can add a couple of trickle vents to the pvc door frame to ventilate the porch? If this would provide enough ventilation, what sort of size + how many vents would I need to use, just to keep the porch aired out?
I don't really want to start knocking out holes for air bricks.

Cheers

Chris

 

[danswift]

Anyone? I have same problem, or would a 4 inch core hole and grill be an alternative?

 

[foxhole]

Would be better to start you own post.
Either insulate the walls to prevent them getting cold or add a couple of vents.