Gas Boiler Room Vent...

[christianbeccy]

I'm currently living in an old house, with a fairly antiquated CH system, the heart of which is an 'Ideal Mexico 2' boiler, which sits in a Boiler Room in the middle of the house. The house is a weird design, having been through some changes over the years, ending up with what I assume was once an outside window now in an internal hallway. That window is open, I'm told to ventilate the room for the boiler, but only open into the house, which we should assume is far from airtight. The 'outside' of the window is directly above a radiator, so a fairly substantial heat loss and one I'd like to address.

The boiler has a proper closed flue, exiting through a chimney stack, so I'm assuming the need for further ventilation is to supply air, not to expel gasses?

There is in fact a low level vent which goes under the floor space to the outside, via 2 side-by-side pipes with grilles on both ends, so I'm not sure why this secondary ventilation 'solution' is needed. Any thoughts? If the 'window vent' is doing anything at all, I want to board over the window and add a simple vent grille as it'll be a nicer solution.

By the way, this is all very temporary, this place will probably getting fully renovated or rebuilt within the next year or two.

 

[Elkato531]

Correct ventilation is essential to ensure the safe operation of open flued appliances like yours. The ventilation has to be correctly sized for the appliance and have the correct type of vent opening. Before you do anything to change the current set-up, get an RGI in to check the ventilation requirements and the current provision.

 

[durhamplumber]

by the way, this is all very temporary

Safety can never be temporary though.

 

[christianbeccy]

Safety can never be temporary though.

That's very true, but it's been through numerous checks with this window scenario and although the heating engineers don't like it, they have never condemned it. Surely I can't over ventilate? I'm thinking of putting in a big vent grille in order to over compensate at least, but can you use insect mesh on this type of vent?

 

[Elkato531]

No insect mesh. The compartment where the boiler is needs to be ventilated and the room where the compartment is needs ventilation to outside or if via another room then there must be a route for ventilation to outside. All these vents need to be correctly sized depending on the appliance and the building layout. If registered people have seen it then its either ok as it is or they haven't done their job properly. It will either be up to specification or not. Its not a question of them not liking it but leaving it anyway. Nor is it something for guess work on your part.

 

[Gasguru]

Sounds like there's a whole load of faults...flyscreens, no lower compartment vent, probable compartment cross ventillation...and these in combination would lead to an "At Risk" category and turning off unless rectified.
I wonder what the flue and terminal are like?
Hope you've got a correctly installed CO alarm...and yes you can make the situation worse if when you're unaware of the standards.

 

[christianbeccy]

Sounds like there's a whole load of faults...flyscreens, no lower compartment vent, probable compartment cross ventillation...and these in combination would lead to an "At Risk" category and turning off unless rectified.
I wonder what the flue and terminal are like?
Hope you've got a correctly installed CO alarm...and yes you can make the situation worse if when you're unaware of the standards.

There are no flyscreens currently. I was asking about whether they're acceptable. I now know they're not.

If you re-read my original post you'll also see that there is a lower compartment vent. The room previously doubled up as a tatty, overloaded storage room and that lower vent may not have been overly visible to whoever advised that the window be left open. I can see daylight through the low-level vent so I cannot see why that isn't enough, that's my question. It appears to be fed via 2 clay pipes of around 100mm diameter each.

It's not ideal, but it isn't as shady as it sounds. The previous occupant was my Grandmother, who wasn't short of a bob or two. Only sadly she's not around for me to ask what the advice was from whoever she had inspect it.

There are CO alarm everywhere, in the boiler room itself, most rooms and in the hallway.

 

[Elkato531]

The advice has still got to be that correct ventilation is very important and that you should get someone in who can make a proper assessment and advise accordingly. Without seeing what is there, no-one can tell you for sure that its safe. CO alarms should provide a warning if things go wrong but they are not a substitute for a correct installation.
It is quite common, unfortunately, for installations to become non compliant due to extensions or other building changes. Is it compliant? Is it at risk of becoming dangerous under certain circumstances? or is it a wonder no-one has died yet? You asked for advice on ventilation. The advice is to get it checked properly.