British ventilation

Two related issues:

First, we just moved out of a modern flat that had an active, 'trickle' ventilation system and into a house that was built around 1925. I was surprised to find that the house (a semi-detached) has vents on all four upper corners of the upper floor. These are essentially holes in the wall covered by a fine mesh grid on both sides. This seems  contrary to American technique, which I recall as intent on sealing up the house to prevent energy loss. So, my question is: what will happen if I seal up these vents? It seems more difficult to keep the house warm than it  should be. (We have double-glazed windows in all but one room of the house.)

Second, two of the rooms on the lower floor of the house have had flue-less gas heaters installed (a pretty glass box with a catalytic converter and in which you can see the flames - a pseudo fireplace, I guess). As a result, each of these rooms also has two vents, one high, one low, and they let in a lot of cold air. These are holes in the wall with fine mesh grid on the outside and a very coarse grid on the inside. i get the impression from the manufacturer's literature that they're there to alleviate the build-up of condensation, and the units do in fact produce a lot of moisture.  We're happy not to use one of these, as the room is small and has a radiator, but the other room is larger (combined living kitchen) and has single pane windows, so it would be nice to use this one occasionally. If i do cover the vents in this room, though, will it effect anything other than moisture? It would seem not, as they are, after all, flue-less. (The landlord has installed CO alarms in these rooms, but a friend told me I should get a monitor that gives me a reading of CO levels.) The only other gas appliance is the cooker, which has a vent fan which I'm thinking I could turn on whenever I use the flue-less heater.

A final question would be what is the best way to seal the vents if i decide to do so?

Thanks.

Ron

If you have a gas powered heating system it is a bad idea to cover up vents.

But Paul will know more when he next logs on. 



Vicky

Why on earth do want to 'fix' something that's not broken?!

Why on earth do want to 'fix' something that's not broken?!

That's what I was thinking.  Why second guess the guys who designed & built the house??

I assume because it is draughty?

It is possible that these vents are no longer needed.  Older gas fires/heating needed open ventilation in rooms such as this.  It may be the ventilation is still needed but it may also be that a new heating system has been installed that doesn't need them.

For instance my living room has a vent because the heating used to be powered by a back-boiler behind the fireplace.  Before I bought the house the fire and boiler were removed and the boiler moved to the utility room.  But I still have  big vent in my living room wall.  I actually quite like it most of the time as it airs the room but a few days a year in winter, if the wind is in the right direction, I can see the attraction of blocking it up.

That being said though, I would never block a vent like this unless you are sure it is not necessary and if your asking questions about it on an expats site that counts as being unsure in my book.

That being said though, I would never block a vent like this unless you are sure it is not necessary and if your asking questions about it on an expats site that counts as being unsure in my book.

Not to mention that elsewhere RonH mentions he's renting.  So I wouldn't do anything without contacting the landlord first.

If he is renting then the landlord should get someone in to do yearly gas safety checks, adequate ventilation is one of the things they check.  Next time ask the gas man if all the vents are necessary and then have a word with the landlord.

If you have a gas powered heating system it is a bad idea to cover up vents.

The heater is gas powered but is outside the living space in a closet.

I should also remind folks that I've asked about two separate sets of vents, so I'm not always sure in your responses which sets you're referring to (perhaps both).

That's what I was thinking.  Why second guess the guys who designed & built the house??

As PR noted, because not all systems necessarily get updated at the same time, and I'll add, because there are often multiple possible ways of designing a house, and it could be a matter of preference rather than of one way being the only correct way. And yes, because it  is draughty.

RonH

First, we just moved out of a modern flat that had an active, 'trickle' ventilation system and into a house that was built around 1925. I was surprised to find that the house (a semi-detached) has vents on all four upper corners of the upper floor.

It's not uncommon to find vents like that on older properties, although by now many have been blocked, either fully or partially.   Where gas appliances are not involved, it's generally all right to seal off these vents, although sometimes it will result in increased condensation.   You need to check that the vents don't serve a dual purpose of allowing airflow into the attic as well.

Second, two of the rooms on the lower floor of the house have had flue-less gas heaters installed (a pretty glass box with a catalytic converter and in which you can see the flames - a pseudo fireplace, I guess). As a result, each of these rooms also has two vents, one high, one low, and they let in a lot of cold air.

The vents are much more a safety issue where gas appliances are involved.  Sealed units which take their air supply from and vent exhaust gases to the outside (usually by way of a balanced flue) aren't a problem, since the combustion process isn't affected by the air in the room.  Anything else which relies upon a free flow of air for proper combustion, or to vent exhaust gases either via the room or via an open flue to the outside world, usually needs at least some minimum standard of ventilation in the room.

It may be that the existing vents are there from an earlier appliance and that the present units would be satisfactory with reduced venting, but it's really something you need to check with the appliance manufacture or a gas engineer who is familiar with it.

It may be that the existing vents are there from an earlier appliance and that the present units would be satisfactory with reduced venting, but it's really something you need to check with the appliance manufacture or a gas engineer who is familiar with it.

These vents on the lower floor were installed specifically for these flue-less gas fires. The instruction manual states that 'the appliance does not require a flue system of any type as the catalytic converter cleans the flue products to provide a complete combustion system', that the room size has to be at least 23 cubic meters to ensure 'correct operation of the fire' ,   and that 100 square centimeters of ventilation must be provided. Later it says that 'some ventilation will be required to prevent condensation', and also recommends that the vents have baffles to prevent draughts, which they do not. The landlord's father is the person who installed everything, which is part of the reason I'm somewhat sceptical, as he seems to be more a 'handyman' than a 'CORGI registered engineer', though he has spoken of taking classes.

RH

and that 100 square centimeters of ventilation must be provided

That would be a vent about 4 inches square, or equivalent.   Does that look about right for what you have fitted?

The landlord's father is the person who installed everything, which is part of the reason I'm somewhat sceptical, as he seems to be more a 'handyman' than a 'CORGI registered engineer', though he has spoken of taking classes.

If the landlord's father is not a CORGI engineer and he's installing gas appliances, that's illegal and extremely dangerous.  If you know that for a fact, insist on a safety inspection by a registered engineer, then get your questions answered then.

When you moved into the property, you should have been issued with an unexpired CP12 (gas safety inspection certificate).  The father couldn't have issued one of those unless he's CORGI registered.  If you don't have one, insist on having a copy.

If the landlord's father is not a CORGI engineer and he's installing gas appliances, that's illegal

Only if he's installing them for remuneration, i.e. effectively as a business.   It's quite legal for a non-CORGI person to install gas appliances in his own property (or to help family etc.).

Hmm, gonna have to disagree there.  If it were your own property, not used in conjunction with a tenancy, then I'd agree with you.

http://www.hse.gov.uk/pubns/indg285.pdf

One of the landlord's main duties is: have all installation, maintenance and safety checks carried out by a CORGI registered gas installer

I'd still be looking for an unexpired copy of a CP12 which must be supplied by a CORGI registered contractor because that would set my mind at ease as to whether it's a safe install.