Blocking air vents for winter

Hi can anyone advise me how to block this air vent for the winter. I won't have any fires lit in the house so I won't need to worry about carbonmonoxide

 

If you're happy its not needed, just cover it temporarily with a sheet of card....whereabouts in the house is it?
John

 

If you are a tenant don't cover it.
Especially if this is a newer property, built post '90.
Any condensation and mould repair will be billed to you.

 

I will be leaving pvc windows slightly open in rooms not used. This room is used and struggled to heat up last year with a pipeing hot radiator. Was like a gale coming through air vent constantly

 

It's the small box room.

 

Newer buildings have cold spots in which condensation and mould form.
That's where they fit those vents, sometimes in really odd places.
At one point I was drilling holes for a living, I went weeks fitting those vents in cheap buildings around my area.
Every day I would get more customers asking me to drill holes for vents, all with the same problem.
And a couple of years later some of the ones who had sealed the vents had mould problems again.
Unfortunately it's the nature of these stupidly designed new buildings.

 

This house was built at least 60 years ago

 

Houses like this often had vents on the outside walls and even above the doors on internal ones.....this was to accommodate open fires or god forbid, the dreaded paraffin heater
Very common up here with local authority properties in particular.
John

 

the one you show is closed by pushing the outer panel half an inch sideways so it slides across and blocks the slots. This is the design.

 

Yeah I know it closes but it has no effect what so ever.

 

perhaps one or both parts is bent and distorted. Take them off for a wash, and see if they work correctly off the wall.

if the wall is not flat it will not seal correctly, but you can put plastic draught excluder round the perimeter of the wall part, so it seals against the wall. Do not tighten the screws so much that they distort the plastic.

A new hit-and-miss vent is very inexpensive.

 

OK and where can I find these covers online?

 

You can remove the cover and stuff the hole with insulation or anything else you have handy.
But as I said, if you're renting don't do it, it might end up costing you a fortune.

 

I will level Windows open locked in other rooms

 

that vent is in two parts. slide the outer section off and cover whats left with white duct tape.