Extractor fans provide intermittent ventilation to remove moisture and stale air from wet rooms such as kitchens, bathrooms and utility rooms.
The SILENT DESIGN 100 is a 100mm domestic axial extractor fan that comes with a stylish solid facia that is suitable for wall or ceiling installations, designed to solve ventilation problems in WC's and bathrooms.
The SILENT DESIGN 125 is a 125mm domestic axial extractor fan that comes with a stylish solid facia that is suitable for wall or ceiling installations, designed to solve ventilation problems in small rooms such as a utility room.
The SILENT DESIGN 150 is a stylish 150mm domestic axial extractor fan that comes with a stylish solid facia that is suitable for wall or ceiling installations, designed to solve ventilation problems in kitchens and utility rooms.
The SILENT 100 is a 100mm domestic axial bathroom extractor fan for wall, ceiling and window installations, designed to solve ventilation problems in WCs and bathrooms.
The SILENT 125 is a 125mm domestic axial powerful extractor fan for wall or ceiling installations, designed to solve ventilation problems in small rooms such as a utility room.
The SILENT 150 is a 150mm domestic axial powerful extractor fan for wall or ceiling installations, designed to solve ventilation problems in bathrooms, WCs, utility rooms and kitchens.
The SILENT DUAL is an autonomous and intelligent extractor fan for bathrooms and WCs. It automatically adjusts its performance according to the environment and ventilation requirements via two sensors: a presence detector and adjustable humidity sensor.
The SILENT 100 ECOWATT is a 100mm energy efficient domestic axial extractor fan for wall, ceiling and window installations, designed to solve ventilation problems in WCs and bathrooms.
The PROFILE 100 is a 100mm ultra slimline axial extract fan for wall, ceiling and window installations. It is designed to solve ventilation problems in WCs and bathrooms.
Extractor Fans are available in two main types: Intermittent Extract Fans and Continuous Extractor Fans, such as those deployed in d-MEV systems. While envirovent offers both types, most standalone, wall- or ceiling-mounted Extractor Fans are Intermittent Extract Fans, so we will focus this discussion on their features and requirements
This type of Extractor Fan is installed in a wet room, such as a kitchen or bathroom, and operates only when switched on or a sensor is triggered. As they are only used intermittently, there is a reliance on background ventilation such as trickle vents and a good level of cross flow of air. These Extractor Fans, coupled with the background ventilation requirements, are suitable for less airtight properties and are typically through-wall. However, there are inline and other options available on the market. The airflow requirement for Intermittent Extract Ventilation is significant, with airflow requirements of up to 60l/s in a kitchen, 15l/s in a bathroom, 30l/s for a utility and some kitchen areas and 6l/s for a toilet. Intermittent Extract Fans are typically offered in 100mm, 125mm and 150mm sizes with control options such as a timer, humidity sensor, pullcord, PIR sensor, thermo-electric shutter and LED light, which are usually integral to the fan itself.
Frequently Asked Questions
An Intermittent Extract Fan provides ventilation during periods of cooking, bathing or when stale moist air is required to be extracted. This can take the form of an extractor fan, a cooker hood or both.
Approved Document F of Building Regulations refers to the use of Intermittent Extract Fans in conjunction with natural ventilation, which typically takes the form of trickle vents in windows as background ventilation. Exact background ventilation requirements depend upon the property. Some of these requirements are quite significant, as background ventilation is the only solution for ventilating the property when these Extractor Fans are not in use.
There are many different options available for Intermittent Extract Fans. These will increase in size and ducting requirements based on the airflow requirements of the particular room. For domestic Extractor Fans, these generally are either 100, 125 or 150mm in diameter.
Intermittent Extract Fans come with a variety of different features, including:
· Status indicators showing whether the fan is on or off
· Electric shutters
· Timers
· Humidity sensors
· Pullcords
· PIR sensors
Generally, Intermittent Extract Fans are basic in their function, but they do have specific uses depending upon the requirements of a property, similar to a d-MEV.
Intermittent Extract Fans are suitable for less airtight properties due to the requirement of natural ventilation and their use only in kitchens and bathrooms during cooking and bathing. In Approved Document F of Building Regulations, Intermittent Extract Fans are not to be used if the as-built air permeability (tightness level) is ≤5m3/(h·m2) at 50Pa.
Intermittent Extract Fans are operated where and when required, such as in kitchens and bathrooms during cooking or bathing. Conversely, d-MEV fans – or Decentralised Mechanical Extract Ventilation fans – run continuously at a low level known as trickle, before boosting during periods of cooking, bathing or when required.
Both Extractor Fan types can have similar controls, such as a humidity sensor, timer or pullcord. But since d-MEV fans are continuously running, they require a much lower level of background ventilation and are typically more silent, with lower power consumption. d-MEV fans also often are only 100mm in ducting size, rather than 125 or 150mm seen in Intermittent Extract Fans, due to reduced minimum airflow requirements under regulations.
Intermittent Extract Fans traditionally have on-unit controls, for timers or humidity sensors, which can be adjusted directly on the fan. For specialist Extractor Fans, wireless or hard-wired options may also be available.
Intermittent Fans and other types of Extractor Fans are required to ventilate to atmosphere to remove the stale, moist air from the wet rooms within the property.
