A trickle vent is a very small opening in a

window A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent materia ...

or other

building envelope A building envelope is the physical separator between the conditioned and unconditioned environment of a building including the resistance to air, water, heat, light, and noiseSyed, Asif. ''Advanced building technologies for sustainability''. Hoboke ...

component to allow small amounts of ventilation in spaces intended to be

naturally ventilated Passive ventilation is the process of supplying air to and removing air from an indoor space without using mechanical systems. It refers to the flow of external air to an indoor space as a result of pressure differences arising from natural forces ...

when major elements of the design – windows, doors, etc., are otherwise closed. Trickle vents are used extensively in Europe and are integrated into window frames to provide minimum ventilation requirements for naturally ventilated spaces.

Energy efficiency ratings

The application of trickle vents in naturally ventilated spaces can help contribute to IEQ Credit 2 under the

LEED Leadership in Energy and Environmental Design (LEED) is a green building certification program used worldwide. Developed by the non-profit U.S. Green Building Council (USGBC), it includes a set of rating systems for the design, construction ...

green building rating system. LEED EA Credit 2 references

CIBSE The Chartered Institution of Building Services Engineers (CIBSE; pronounced 'sib-see') is an international professional engineering association based in London, England that represents building services engineers. It is a full member of the Co ...

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 Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to ...

, avoided over ventilation (minimizing

energy consumption Energy consumption is the amount of energy used. Biology In the body, energy consumption is part of energy homeostasis. It derived from food energy. Energy consumption in the body is a product of the basal metabolic rate and the physical activity ...

), and improved comfort through draft avoidance.

Drawbacks

The US Standard,

ASHRAE The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE ) is an American professional association seeking to advance heating, ventilation, air conditioning and refrigeration (HVAC&R) systems design and constructio ...

62.1-2007: Ventilation for Acceptable Indoor Air Quality, only requires 4% of net floor area to be operable. This creates the potential for increased energy consumption where natural ventilation is provided by operable windows where supplemental

air conditioning Air conditioning, often abbreviated as A/C or AC, is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as 'comfort cooling') and in some cases also strictly controlling ...

is provided, in addition to generally poor control over ventilation rates during hot summer or cold winter conditions.

Energy efficiency ratings

Effect on indoor environment

Drawbacks

Further reading