Trickle ventilation in buildings
Ventilation is necessary in buildings to remove ‘stale’ air and replace it with ‘fresh’ air:
- Helping to moderate internal temperatures.
- Replenishing oxygen.
- Reducing the accumulation of moisture, odours, bacteria, dust, carbon dioxide, smoke and other contaminants that can build up during occupied periods.
- Creating air movement which improves the comfort of occupants.
Ventilation in buildings can be either natural or mechanical. Mechanical ventilation tends to be driven by fans, whereas natural ventilation is driven by ‘natural’ pressure differences between one part of the building and another.
Modern buildings tend to be virtually sealed from the outside, and modern, naturally ventilated buildings can suffer problems such as condensation when windows or other ventilators are closed, for example in the winter or at night.
As a result, ‘trickle ventilation’ may be provided to ensure there is always an adequate level of background ventilation. Trickle ventilators are typically manually controlled slots incorporated into window frames. They are generally operated by opening or closing a flap depending on the need for ventilation, however they are intended to be left in the open position.
Trickle ventilation can also be provided by ventilation slots in the glass itself.
It is recommended that trickle ventilators are located approximately 1.7m above the floor level to avoid creating cold draughts.
Trickle ventilators can be self-balancing, with the size of the open area changing automatically depending on the air pressure difference across it, reducing the risk of draughts during windy weather.
‘Crack’ settings (or night latch positions) that allow windows to be left slightly open are not generally recommended as a means of providing background ventilation because of the risk of creating draughts and because of security concerns.
The requirements for ventilation in the UK are set out in the Buildings Regulations Part F, Ventilation.
NB Short Guide, Fabric Improvements for Energy Efficiency in Traditional Buildings, published on 1 March 2013 by Historic Scotland, defines a trickle vent as: ‘A small opening in a window or building component to allow for ventilation, where natural ventilation should occur but may be impinged.’
[edit] Related articles on Designing Buildings
Featured articles and news
Recharging Electrical Skills in Wales
Step by step collaborative solutions.
Ireland budget announcement 2025
CIOB responds with positivity, criticism and clarity.
The continued ISG fall out, where to go?
Support for ISG contractors, companies and employees.
New HES national centre for traditional building retrofit
Announced as HES publishes survey results which reveal strong support for retrofit.
Retrofit of Buildings, a CIOB Technical Publication
Expected to become one of the largest activities in the global construction industry.
Scope determination appeals and the Building Safety Act
Process explained following release of appeals guidance.
The ECA industry focus video channel
Keeping update with the industry session by session.
Over 25 recorded informations sessions freely available.
AT Awards 2024 ceremony East London October 25th.
Revisiting the AT community at the 2023 awards evening.
The Community Housing Fund and built affordable homes
CLTN reviews the impact of the Fund and calls for extension.
The grading system of the Regulator for Social Housing
A background, an explanation and ten recent enforcements.
Construction, repair and maintenance. Book review.
Putting new life into a city with a 1900 year history.
BSRIA Briefing 2024: Sustainable Futures speakers
Redefining Retrofit for Net Zero Living 22 Nov.
Wall of support for post-Grenfell regulation of electricians
Call for a shake-up of the construction industry highlighted on radio.
Digital sustainability through future AEC tools
Bringing together industry and academia to meet challenges.