Trickle vent

A trickle vent is a very small^[quantify] opening in a window or other building envelope component to allow small amounts of ventilation in spaces intended to be naturally ventilated when major elements of the design—windows, doors, etc.—are otherwise closed.^[1][2] Trickle vents are used extensively in Europe and are integrated into window frames to provide minimum ventilation requirements for naturally-ventilated spaces.

Open Trickle Vent built into a window frame

Energy efficiency ratings

The application of trickle vents in naturally-ventilated spaces can help contribute to IEQ Credit 2 under the LEED green building rating system. LEED EA Credit 2 references CIBSE Applications Manual 10, which provides advice on the design of naturally-ventilated spaces, recommending the installation of trickle vents in naturally-ventilated spaces. Within the UK, the application of trickle vents is required to meet the requirements of the Building Regulations; requirements are described in Guide F, Means of Ventilation.

Effect on indoor environment

Trickle vents will help avoid problems associated with poor ventilation in naturally-ventilated spaces, including reduced risk of condensation, avoided over-ventilation (minimizing energy consumption), and improved comfort through draft avoidance.