Trickle vents, extractor fans and passive stack are ventilation strategies often used in traditionally built homes.
The Basics: Trickle vents with extractor fans
This is the most commonly used ventilation strategy. It uses trickle vents, typically in walls or windows of the living and bedrooms, to allow air into the property. Extractor fans are used in the bathrooms and kitchen to expel humid and/or smelly ‘dirty’ air.
The Basics: Passive stack
Passive stack also works by allowing air into the house via trickle vents. The extract is done by a pipe running from the vents in the bathrooms and kitchen of the building and terminated at the roof. Air from these rooms will be extracted through the pipe by both the venturi and stack effects. The venturi effect is a low pressure created by the wind blowing over this pipe. The stack effect is the pressure differential between inside and outside the building caused by differences in air density due to the indoor/outdoor temperature differences.
Hausmate enhancements: Demand control ventilation (DCV)
Hausmate’s demand control ventilation control adds a level of intelligence to any ventilation strategy. Hausmate DCV monitors the air quality in all rooms of the building as revealed by humidity, CO2 and optional Volatile Organic Compound (VOC) sensors. On the basis of the air quality, it operates appropriate fans to exhaust the stale air and damper valves in appropriate trickle vents to allow fresh air into the building. Hausmate will always ventilate the rooms with the worst air quality, so that the improvement is as rapid as possible. DCV has low capital cost and has been shown to be very energy effective. DCV does not require the installation of ducting passing throughout the building, so it is suitable for retrofitting to existing properties.
A combination of trickle vents and extractor fans is the simplest and most common ventilation strategy in UK buildings.