Timer Controlled Extractor fans with a built-in timer control means that the fan will operate with the bathroom light switch and then overrun for a set amount of time to continue removing moisture from the air. This is great for steamy bathrooms, allowing you to turn the light off but continue with extraction for a short time. Axial Axial type fans cause gas to flow through in an axial direction which is parallel to the shaft where the blades rotate, making the flow axial at exit and entry. Axial fans are designed to create a pressure difference and force which produces a flow through the fan. 24 L/trs Extraction Rate Building regulations stipulate that extractor fans need to be able to extract at least 15 litres of air per second. It?s needed to ensure a minimal build-up of moisture in the room, reducing mould and grime in damp areas. This fan will extract a crazy 24 litres per second! That?s almost twice what?s recommended! Zone 1 Rated IP rating stands for ‘Ingress Protection