System 1 - Intermittent fans  

Part F Building Regulations requires standard intermittent extractor fans in new buildings (such as bathroom and kitchen extractors) to have their air flow rates measured on site and the results submitted to the building control body prior to completion.  

The process of testing is known as flow rate testing. 

As buildings become more airtight, it is essential that ventilation systems function correctly, especially to remove moisture from the dwelling. 

Intermittent extract fan is a mechanical ventilator that does not run all the time, usually only when there is a need to remove pollutants or water vapour (e.g. during cooking or bathing). Intermittent operation may be under either manual or automatic control. 

Approved Documents L1A & L1B require that buildings be designed to be more airtight and minimise uncontrolled ventilation through the building fabric. This helps reduce heat loss and improves SAP performance. However, it also removes a ventilation source, and unless the ventilation system of the dwelling provides sufficient air movement, then this can lead to damp and condensation issues within the building. This flow rate testing is to ensure that the ventilation system as installed meets the Building Regulation. 

ATSPACE test engineers are all qualified in Part F ventilation testing and can provide testing on buildings using System 1 ventilation or intermittent fans.