Trickle vents in windows work?

Has anyone got trickle vents in their properties. Been recommended to fit them to existing windows in a tenanted ground floor flat with condensation problems. Even though have air bricks in some rooms

if you have air bricks you dont need trickle vents Check they are clear thru the wall and not cemented up outside. Fit humidity sensitive fans in bathroom and kitchen. I have trickles in my kitchen but put the de humidifier on to keep the moisture down as alone trickles are not enough

Thank you for the advice Colin :+1:

P S When i say I put the machine, on I have a portable machine. Ironically I have automatic humidity fans in my properties but dont have one at home !

I have seen trickle vents in double glazed window units. They do not seem to cause draughts. However, they usually have a manual over-ride, a little like venetion blinds where you can pull a cord to close the slats to reduce the light coming into the room - this is an analogy, as the vents operate differently. If the tenant thinks their use will cause a draught or result in higher energy bills, they are likely to close them. Unless you could make it a condition of the tenancy to leave them open, explaining why, and so it will or maybe ignored, or arrange for the closure mechanism to not function, then the condensation problem is likely to continue if these vents are fitted, because most people want to save on energy costs and don’t recognise the potential consequences of not preventing condensation.
If you already have lockable top windows that can be opened and locked in position as mine, about a half inch from the closed position, then get them to do leave them open but locked to prevent access: they will be your trickle vent substitute! Sadly, until mould gets out of hand, the tenant is not likely to do that: but do tell them it is essential to do so to reduce condensation and it will mean they won’t have as much to do to keep the mould at bay.
Condensation is a life style issue. In addition to, or instead of humidity sensing fans that cannot be disabled and are always automatically turned on, the best you can do is give them a condensor tumble dryer with instructions on its use, or better still one that vents to the outside of the property. Unobstructed air bricks are needed, or draughty external doors!
A single de-humidifier is unlikely to be of much use: you need one on at least each floor or in each room where moisture is generated, e.g. where clothes are dried indoors and in or near bathroom and kitchen, and ideally in each bedroom. It is far cheaper to prevent condensation with a tumble dryer and air circulation than to remove it by use of dehumidifiers! Fans help enormously if used.
Good luck.

The biggest cause of condensation is indoor clothes drying and closed bedroom doors at night, apart from leaking water pipe joints and uncovered kitchen pans in cooking and unopened windows when showering, hence fans are recommended for kitchens and bathrooms.

Condensation: water vapour needs something cold to ‘condense’ on, like your walls, floor, doors and mirrors. If they get cold they’ll get wet. Heat is the answer!

Hello Colin,
Yes always have trickle vents, especially if you are having new windows made and fitted. when the window is assembled on site you can fit the trickle vents without the manual close flap if the property is a real problem to prevent them being closed.
With regard to air bricks, again essential. If you have the old clay air bricks cut them out and replace them with plastic ones. Why you may ask? Well place a clay one next to a plastic one and consider for a moment how much more of the plastic ‘brick’ is open as a vent compared to the clay one. A clay brick probably has around 35% of the vent area a plastic one has.
You can also fit vents into the top and bottom of all internal doors (and walls if needed) to allow air to circulate more freely.
The absolute final solution is to fit a specialised forced air system, usually a unit in the loft that gently pipes air through the property.
Good luck.

If you’ve got uPVC double glazed windows fitted you probably already have a trickle vent capability on all windows. They can be locked ajar to provide ventilation. If they are the top hinged variety there will be one or two ridges at the top of the fixed pane that the window handles can lock against. Not many people know this, but I tell all my tenants.

The rest is just education about the physics involved. Mould is caused by fungal growth on damp areas. Damp areas are usually caused by condensation. Warm air can hold more moisture than cold air, hence keeping a place at a reasonably warm and stable temperature. Moist air needs to be changed by opening windows on dry blustery days and doing things like drying washing inside adds to the moisture content in the air. The tenant needs to strike a balance in how they use a place. So whereas a lot of the discussion tends towards devising foolproof ways of stopping a tenant overriding stuff like ventilation, I’ve found it is better to educate people and work with them to strike a balance that works for them. On occasion I’ve even bought dehumidifiers as part of the solution. I’ve been struck by how little people understand about living in properties, stuff that people like me who grew up with single glazed metal windows, no central heating etc have learnt in order to keep houses dry.

Mark .never thought about taking out the manual flap. Good point. Worth noting that most building inspectors require trickle vents to pass a job

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Enjoyed your info on trickle vents. Lots of people don’t realise stagnant moist air will cause mould, simply by keeping air moving prevents mould, provided there is no established mould initially.