Fireplace place air vent

[biscuit]

Hi hope this is the correct section, we are in the process of redecorating an upper bedroom and looking at closing the fireplace up, i realise a closed one should be vented for air circulation but downstairs we have a gas fire in the living room and a gas open basket in the dinning room all, so, to my mind it's got ventilation, or do i still need to ventilate upstairs, many thanks 

[Redbeard]

Unless something has gone horribly wrong your 3 flues, though they may share a masonry 'home', should be entirely separate, so yes, arguably ventilation still required. The 'beef' I have with flues on an internal or party wall (anything but an external wall, I mean) is that your vent is potentially pulling warm moist air into the redundant flue, and as it nears the cold roof void there is a chance that it will condense. This may then push nasty tarry 'products of combustion' through the plaster, so that apparent 'damp patches' are sometimes not only that, but also contamination. If it's on an outside wall, ventilate externally, but be sure you know which flue you are entering!

[biscuit]

It is on an internal shared wall, were looking at moving a rad on this wall as it's going to be the only open wall available, not sure if there will be any issue with an airbrick behind this rad though ??