Lockable outside air vent cover

phil24_7

What about installing a cat flap. These are lockable and some with even operate via a pet chip in the neck of said animal, stopping unwanted animals from getting in!

peachyprice

stator wrote: »

If they're trained to come in and out of the vent and they are trapped in a room and the only open exit is the vent, they will come out.

If the grille is locked all the time they won't know this is a route of escape. You can certainly train them to use it as an entrance/exit, but for it to be any use in an emergency it will have to always be available. A pet is not going to remember the 'emergency exit' in a fire, it's either going to go for it's usual exit or hide. Expecting it to know that it is for emergency use only is frankly a little ridiculous.

stator

Alter_ego wrote: »

I wonder why the grill needs to be lockable.

To keep out miscreants of course.
Who knows what nonsense kids get up to these days.

chappers

Have I just entered a parallel universe all this talk of pets escaping down a ventilation grill for a fire.
What sort of bloody emergency is going to require it to be removed any quicker than undoing 4 screws and why do you need to lock it are you expecting an invasion from a crack squad of rats armed with screwdrivers.

stator

The idea is that the grill would be padlocked into place over the top of some kind of staple. The other side would be hinged. So undoing the padlock would allow it to be removed immediately.

I should mention the air vent is no where near the fire. It's just a 120mm tube with a plastic grill on either end. It provides air flow into the room because of the fire. It's located at floor level and goes straight outside through the wall. So you can see the outside from the inside. Removing the cover you could stick your arm through. I really don't think it's unlikely that any animal would try to escape through it if it was unimpeded and the room was filling with smoke.

phil24_7

I have never heard of a house needing a 120mm hole in the wall at floor level...especially for a fire and boiler. I thought boilers were all sealed? Is you house that well sealed that the fire doesn't get enough air???

It seems a very weird set-up and you seem to be making an even more weird use for it!!!

stator

It's an old back boiler, which is mounted in the chimney.

Wall mounted modern boilers have a combination flue that allows the boiler to suck in fresh air and vent out waste hot air.
A back boiler vents up the chimney but it has no where to get the fresh air from, so it takes it from the room. This is fine as long as there is fresh air being drawn into the room. If the room is sealed then the oxygen will get depleted and carbon monoxide will be produced.
So according to building regulations all such boilers have to have ventilation to allow fresh air into the room where the boiler is.

phil24_7

Ah, ok, is your house reasonably air tight?. Why is the vent at floor level though, and why 120mm?

wrightk

phil24_7 wrote: »

Ah, ok, is your house reasonably air tight?. Why is the vent at floor level though, and why 120mm?

building regs state vents need to be no higher than 400mm from floor level. this is to prevent smoke spreading rapidly/high up through a building

120mm is probably the size pipe based on how many mm2 free air space is required for the size of back boiler to ensure there is enough fresh air entering the room for combustion to take place

stator

I've done the calculations myself and a 12cm tube does seem to be overkill, but the hole is already there