It would seem that the vast majority of trickle vents are kept closed all the time

They are therefore a waste of time and money and hence the opposite to sustainable - antisustainable!

Whose idea were they and why are we still using them , many of the homes they are in have more draughts through air leakage paths than the tv's offer even new houses.

they are a regulation draught

'Why do we put up with such rubbish in our homes'
Because we british are conservative with regard to buildings , not generally keen on any sort of change.
Most client like to see thing they're used to . it makes them feel secure.
Trademen make a living doing it the way they know, new stuff creates a risk to thier potential income.

With a bit of discussion building inspectors will accept an opening lockable vent on the window as sufficient background ventilation to comply with regs. thus doing away with trickle vents.

<blockquote><cite>Posted By: jamesingram</cite>Trademen make a living doing it the way they know, new stuff creates a risk to thier potential income.</blockquote>

There's a great deal of truth in that statement. I've been hunting around for a builder to build my new house for a while now, and the vast majority very clearly feel uncomfortable about my obsession with insulation levels, absence of cold bridges and air tightness. One even had the audacity to tell me not to worry about all that stuff, as he'd been building houses for years and it just wasn't necessary...........

"One even had the audacity to tell me not to worry about all that stuff, as he'd been building houses for years and it just wasn't necessary"

Thing is, Jeremy, it never used to be!

The question (that has spontaneously appeared in a thread that was quite specific in its subject) needs turning on its head: "Why should we need to save energy that we shouldn't be using so much of in the first place?"

As for trickle vents, they weren't intended just for ventilation to keep condensation down, they were intended to get a supply of fresh air to whatever means of combustible material you were burning to keep warm. In one instance I had a BCO who insisted that I fit permanently-open trickle vents because there was a coal fire in the room, and that was a concession in place of an air brick, new draught-proofed doors having been fitted.

In that situation the only alternative is MHVR on whatever scale.

In terms of condensation, the crazy thing was that vents were only mandated in 'habitable' rooms, ignoring the rooms where condensation was most likely to occur!

Oh, and things were eventually relaxed on replacement windows, when if trickle vents hadn't been fitted originally they didn't have to be fitted on the new windows if night-vent catches were fitted. So someone eventually woke up to the stupidity of making a higher performance window and then putting bloody great holes in it.

The whole subject of ventilation in houses is something that seems to have been approached from a very unscientific way, in terms of the regulations. I can understand how, as people wanted more comfortable and less draughty homes, the powers that be became concerned about ensuring adequate supplies of fresh air, both for any combustible fuel appliances and the occupants.

It seems that windows were chosen as a means to do this, not because that was the logical thing to do (who in their right mind buys a nicely sealed, well-insulated, new window and insists in drilling holes through it?) but because it was a practical way of addressing the potential problem that retrofitting new windows to an existing house might cause. The gross stupidity was to apply the same logic (the insistence on having trickle vents) to new build houses, where far more effective and efficient ventilation methods could be designed in.

Over the years that I've been improving my current house (in terms of reducing energy usage) I've created some significant problems that a properly designed whole house ventilation scheme could have avoided. For example, when I increased the insulation in the loft, I created vast amounts of condensation on the sarking, which then drips down and forms pools, eventually soaking through the ceiling (which is how I found out about it). The roof space is ventilated at the gables, but not enough to deal with the problem, so new soffit vents had to be fitted. When I replaced all the windows and doors with new, far more thermally efficient, ones (the old ones were 1980's standard DG that used to attract condensation) I created a condensation problem on the north wall internally, which manifested itself as black mould growing behind furniture. The fix for that was to move the furniture away from that wall and fit cavity wall insulation, to get the internal wall temperature above the dew point. The consequence of fitting cavity wall insulation has been that the windows are now the best condensing surfaces once again................

Having been through this learning process, I'm now quite clear about what I need to do in the new build. I also know full well just how much of a nuisance, and how ineffective, trickle vents are.

first thing I did on my aunties house up in inverness / black isle when looking at her energy saving / condensation issues was to remove the metal trickle vents from the windows, stuff them with sheeps wool insulation and put them back on again.

essentially all they were doing was creating a highly conductive cold bridge to the outside air, which with minus 15 type winter air temperatures, was just wicking heat out of the house, and causing huge condensation problems on the windows as the water would condense on the trickle vents and then run down the windows.

they never had them open anyway and had no need of them as it's a huge bungalow with MHRV in the bathroom and drying room, and the ceiling and walls are vapour permiable with lots of ventilation to the loft. Air tightness wasn't likely to be particularly high either.

The metal temperature on the inside rose from about -10 to about 8 degrees immediately after doing this, and the next morning the window sills weren't dripping wet as they had been every other morning.

I agree - trickle vents, particularly metal ones are total madness.

eta - and their oil boiler is in the garage and always has been, so there's no excuse there.

Posted By: jamesingramTrademen make a living doing it the way they know, new stuff creates a risk to thier potential income.

Posted By: Joinereventually relaxed on replacement windows, when if trickle vents hadn't been fitted originally they didn't have to be fitted on the new windows if night-vent catches were fitted.

Posted By: joe90so we fitted them but we didnt cut a hole in the window frame

We sort of combine all 3 of those. Some D/G replacement windows had trickle vents. Q: Why? A: 'Cos that's what we always do. It's the regs...
The front of the house straight into SW gales and the draught though the vents was far from a trickle even when firmly closed. We'd also discovered by then that they didn't really need to have been there in the first place.
Our solution was to remove the fittings (a shaded grill on the outside, & a flap on the inside), then working from each side use just enough silicone to replace the "skin" in each face of the frame where the slot had been routed out, then replace the fittings. It now looks as though we have trickle vents, but there's no point in trying to open them - and no draught through them. If we want extra ventilation we have opening windows, with night latches...

Why does corporate greed favour trickle vents?

Do you mean because it's the cheapest way to make a big-enough hole in new-build?

Back in the mid-80s I works-managed a very big replacement window factory producing many hundred of windows a week for large local authority consortium contracts all over the UK, but mainly London and its tower blocks. Aluminium was still the main material back then, upvc rapidly catching up (we opened up a new factory to cope with the increasing demand). I had the impression that trickle vents came in because the upvc industry (in fact the replacement window industry generally) were fitting cheap handles without night-vent provision. But that situation was no different to what was there originally, it was just perceived as a bad thing because someone had the bright idea that the effects of dampness in the housing stock could be mitigated by better ventilation, with the bonus that health could also be improved. Night-vented handles had always been an option, but one that had to be specified and paid for. The obvious simple solution of making night-vent handles mandatory seemed to pass the regulatory authorities by - probably because they didn't know they existed as an option, having visited only properties with cheap handles fitted when they did their "research"!

Posted By: wookeyWhy does corporate greed favour trickle vents?

Do you mean because it's the cheapest way to make a big-enough hole in new-build?

Well, it's easiest. The holes arrive pre-installed in the window. Drilling holes in walls and then capping them probably involves two trades and the possibility of all kinds of ghastly mistake. And windows can probably be made cheapest at least in a paper analysis if they aren't in reality.

Posted By: fostertomoverlook the (recently tightened) rigidity of the Regs wording and accept night vent latching instead

What are the current regs? Is there some perceived issue about the security of night latches?

<blockquote><cite>Posted By: StuartB</cite>How did the Victorians manage their ventilation and condensation issues? They normally had a simple effective solution.</blockquote>

The simple answer is that they didn't need to. Their houses leaked like sieves, through the window and door frames and pretty much everywhere else, plus they used open fires in several rooms of a house, giving fairly effective ventilation.

The downside was the large amount of fuel needed to heat homes like this, which ultimately ended up with big cities, like London, becoming renowned for thick fog that killed thousands every winter.

Not to mention the 1000 miners a year¹ who died digging the coal to heat the houses (and lots of other uses, of course).

¹ I think that was the number around 1910 or so.

uPVC window frames usually have two or more chambers, so they are the plastic equivalent of triple glazing.
One thing which bugs me about trickle vents is that they destroy the separation of the chambers, which must greatly increase the heat loss through the frame. So on some of the windows I took off the inside cover of the trickle vents and squirted expanding foam into the chambers either side of the trickle vent area to reinstate the separation of the chambers. This could very easily be done at the factory, or they could go the whole hog and fill the whole frame with foam.

Steamy Tea, you are correct. Fuel is way too cheap. In my world it would all be different!...
Not until a brave government taxes the hell out of domestic fuel will people see the need to reduce their consumption. The tax raised would pay for the 90% of UK housing stock that doesn’t even meet Building Regs U-values to get some proper insulation, double glazing and draught proofing.
Controversially, I use coal (as well as wood) to heat my house. I burn it at 75% efficiency in my stove. The coal power stations struggle to achieve 40% efficiency creating electricity then everybody with a heatpump tells us how green their installation is cos they make no NOX,SOX and CO. It’s all wrong. When will the world wake up to reality?