Air vent in bedroom 1930's semi

Hello all.

I'm in the process of renovating my 1930's semi and have come accross an air vent in one of the bedrooms. It is just above the picture rail . I've looked with a torch and poked around to find the external vent ( daylight). It appears to be built into the wall (cannot see the cavity) and there are bricks on the sides and bottom of the inside of this vent. It also appears to channel upwards? Possible into the roof space? Is this normal for that age house?
On the exterior of this wall I can see the vent which lines up with the interior one but there is another vent at the same height around 0.5m away horizontally from it. would this be ventilating the cavity or roof space?
Anyway, just wondered if anyone could shed some light on the subject and then I would be able to decide wether or not I could block the internal vent.

Thanks in advance.

Mark.

If you have window frames with trickle vents, then no real need for this. You can just cover it up internally and ignore the outside.

I'm reviving a 2-month old thread here, apologies to anyone who detests old threads raising...

I have a house from the 1920s, and the house was built with many more vents than you would see on a modern house... The house originally had 5 fireplaces, and there is an original vent in every room that did NOT have a fireplace, including one in the room that would have been the coal bunker.

I have also found extensive town-gas pipework buried in the walls and hidden under floorboards (immaculately installed, BTW!)

My theory is: rooms that have a fireplace are, by the nature of having a chimney, well-ventilated. Many people with large fireplaces in their living rooms enjoy the cool-feeling of their living room in summer due to this ventilation. Why put a vent in a room that's already well-ventilated?

So, the vents in the non-fireplaced rooms are to improve ventilation... why? I reckon one or both of the following:

1) Because people back then were firm believers in getting some fresh air into your lungs (arguably the reason asthma was little-known back then)
2) Town-gas was mostly carbon-monoxide, so if you have town-gas lighting and appliances you REALLY want to ensure that room is ventilated in case it goes out.

Donkmeister said:

I have also found extensive town-gas pipework buried in the walls and hidden under floorboards (immaculately installed, BTW!)

)
.

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that`s because it was done by plumbers the prima donnas had yet to emerge onto the stage

Donkmeister said:

My theory is: rooms that have a fireplace are, by the nature of having a chimney, well-ventilated. Many people with large fireplaces in their living rooms enjoy the cool-feeling of their living room in summer due to this ventilation. Why put a vent in a room that's already well-ventilated?

Click to expand...

You often find vents in rooms with fireplaces, because new air needs to be drawn to the fire as it burns and the products of combustion are drawn up the chimney. That's why current building regs require fixed ventilation for new fireplace and stove installations above a certain heat output.

Cheers
Richard