10 year old 'estate' house.
On the walls, low down either side of what was an open fire and is now a wood burning stove there are two dirty, overpainted plastic grilles. I unscrewed these to see how big the actual vent holes beneath are with a view to replacing them. (Holes are 150mm square). Thing is, looking through one 'shaft' through to the external wall you can see straight through to the external wall grille (the sides are lines with 'terracotta tile').
The other has a wadge of fibre glass orange insulation roll put in loosely which I can easily pull out.
Though it may seem trivial, my question is which is correct? It strikes me you'd lose a lot of heat AND get a fair old draught through the un-fibreglassed side BUT does having fibre glass in the other vent render it unsafe? You can still detect a draft even with the fibre glass in situ but the un-fibreglassed side does have a bit of a howling gale coming through it!
On the walls, low down either side of what was an open fire and is now a wood burning stove there are two dirty, overpainted plastic grilles. I unscrewed these to see how big the actual vent holes beneath are with a view to replacing them. (Holes are 150mm square). Thing is, looking through one 'shaft' through to the external wall you can see straight through to the external wall grille (the sides are lines with 'terracotta tile').
The other has a wadge of fibre glass orange insulation roll put in loosely which I can easily pull out.
Though it may seem trivial, my question is which is correct? It strikes me you'd lose a lot of heat AND get a fair old draught through the un-fibreglassed side BUT does having fibre glass in the other vent render it unsafe? You can still detect a draft even with the fibre glass in situ but the un-fibreglassed side does have a bit of a howling gale coming through it!
