Should I have trickle vents?

thedr

I'm in a 2nd floor flat. My old UPVc windows are dead and I'm replacing all of them.


The flat has south facing windows and is generally very warm (Boiling in summer). However, the bedroom (which is on the end of the building, and we don't have cavity wall insulation), can get cold at night. There's an additional problem in that the old windows are draughty and generally very cold in the winter (The gap between the inner and outer panes is minimal).


The person replacing my windows with all-new, wide-gap, singing & dancing windows has offered to put trickle vents in for no extra charge.


I know that they can be completely closed or opened.


However, I'm really paranoid about draughts, especially in the bedroom, which has a substantial drop in temperature at night (Now, in April, it goes from 21C to 18C, which is too cold for me). I am a light sleeper, draughts affect me, as does being too cold.


In the winter, being on the 2nd floor, and the windows being quite large, I can feel the cold coming from the existing windows. This I'm sure will be resolved with the new windows. But then there's the heat insulation question at night in winter. I don't have my heating on at night because it's too noisy (The pipes expanding and contracting). I would rather my bedroom be unventilated and warmer, than cold with a draught. Yes, I know the vent closed will stop airflow, but will it be completely efficient at keeping out ALL draughts and stopping heat loss?



On the plus side, I find the idea of having some ventilation in spring, without the need for opening the window (I'm not too far from an airport), something I'd like.

My question is ...


To trickle vent or not to trickle vent?

Nada666

Do you work night-shifts? If not, there are these marvelous new-fangled contraptions that use amazing shape-memory-retaining materials that are available in a wide variety of colours and patterns. They are know to the trade as 'curtains'.

Install the windows with trickle vents and spend money on fitted curtains if you really need them. That gives you the flexibility of both.

thedr

Nada666 wrote: »

Do you work night-shifts? If not, there are these marvelous new-fangled contraptions that use amazing shape-memory-retaining materials that are available in a wide variety of colours and patterns. They are know to the trade as 'curtains'.

Install the windows with trickle vents and spend money on fitted curtains if you really need them. That gives you the flexibility of both.

Thanks but I want clean lines. I'm doing away with curtains in the bedroom and have custom made blackout blinds, which work well.

If trickle vents cause drafts when closed then it's defeating the object of having well insulated windows, and I'd prefer not to have them. But the question is do they?

adouglasmhor

If you don't have them in a room which is cold at night and not ventilated you seriously run the risk of condensation and mould.

thedr

adouglasmhor wrote: »

If you don't have them in a room which is cold at night and not ventilated you seriously run the risk of condensation and mould.

I know the room. I've been there for 10 years. When the current windows were in good condition I did not need to have them open at night, and there was no problem with mould and condensation. Daytime airing was fine.

And I still don't have an answer to the question: do trickle vents cause draughts and heat loss even when closed? If so, it's plain stupid to have them in my opinion. You can always open the window.

WestonDave

As above if you slow the rate of air change in the flat the humidity levels will rise (as you breathe out, you breathe out wet air, add in showering, drying clothes etc and there is a lot of water being added to the air). With uninsulated walls that high humidity will lead to condensation on the walls (particularly behind furniture where there is poor airflow of warm air) and if not mopped down you'll have mould growing on it.


In a flat you have less options so if you don't want "opening the window" to be the only option for ventilation given the above, I'd have them. They are unlikely to be draughty enough for you to notice when closed albeit they may not be totally air tight.

Smiley_Dan

There are very few building materials that are completely airtight. Even bricks have a degree of air permeability. The real answer to your question is, like all difficult but worthy questions, "it depends". Are you willing to install proper ventilation as your air tightness improves? That becomes more difficult if you don't own the freehold. Furthermore, the payback time on such solutions are quite far in the future.

That, and the fact that you don't want mould, is why the default answer to your question is "yes".

adouglasmhor

thedr wrote: »

I know the room. I've been there for 10 years. When the current windows were in good condition I did not need to have them open at night, and there was no problem with mould and condensation. Daytime airing was fine.

And I still don't have an answer to the question: do trickle vents cause draughts and heat loss even when closed? If so, it's plain stupid to have them in my opinion. You can always open the window.

Mine in the bedroom dont have a draught when closed, but our bathroom one does when the wind is straight on.

You can leave the trickle vents open when you go out, leaving a window open is not always practical. And your insurance might not like it.

Mojisola

thedr wrote: »

I know the room. I've been there for 10 years. When the current windows were in good condition I did not need to have them open at night, and there was no problem with mould and condensation. Daytime airing was fine.

And I still don't have an answer to the question: do trickle vents cause draughts and heat loss even when closed? If so, it's plain stupid to have them in my opinion. You can always open the window.

I wouldn't have them - I don't see the point in having draught-free, sealed windows and then putting holes in the frame.

I'd rather use the option of opening windows or running a dehumidifier if condensation did become a problem.

WestonDave

To give a personal opinion - my plans at present for our house are to put in new windows without trickle vents but to put in a MVHR system to counter the air quality issues. I appreciate that this may be a more expensive solution but the MVHR allows ventilation with filtration which with me suffering at present with hayfever and my wife due to start once the grass season starts is a worthwhile benefit. If I couldn't put in another form of ventilation then I would have trickle vents even though I'm pretty serious about energy efficiency because of the humidity issue. My personal opinion is that as British housing stock becomes better insulated and more air tight (in search of lower energy bills) the next big problem people will encounter is a rising number of condensation damp problems.

thedr

adouglasmhor wrote: »

Mine in the bedroom dont have a draught when closed, but our bathroom one does when the wind is straight on.

You can leave the trickle vents open when you go out, leaving a window open is not always practical. And your insurance might not like it.

I live in a really safe, upmarket area and being 2nd floor, I feel really safe in leaving a window open when I go out.

I may not go for trickle vent in the bedroom.