How to select a Utility Room Extractor Fan

edited July 2017 in Utility

Legislation indicates a Utility Room should extract air at a rate of 30 Litres a second (Part F), as you can imagine Utility Rooms come in all sizes so how effective the 30L/S rate will be depends on your Utility Room size, we would suggest an acceptable extract rate is a minimum of 20 air changes an hour, to check if 30L/S or 20 air changes an hour is required for your Utility Room firstly you need to measure the size of your Utility Room, the examples below have the room measurements in Metres.
A Utility room for the purposes of this guide is a room or area where your Washing Machine and or Tumble Dryer are housed
If this area is included in your Kitchen area, please use the kitchen fan guide and include this area in your measurements.
Let's say the length of your Utility Room is 3 metres, the width is 2 metres, and the height is 2.4 metres.
That would be: 3 x 2 x 2.4 = 14.4m3 (the volume).
For a Utility Room we recommend 20 air changes an hour, or a minimum of 108m3 an hour (or 30 litres a second).
In this example the amount of air that should be extracted from the Utility Room is:
• 14.4m3 (the area of the Utility Room)
• x 20 air changes an hour
• = 288m3/hr
This is above the minimum we recommend of 108m3/hr.
So in this example the fan required for a Utility Room 3 metres x 2 metres x 2.4 metres is:
288m3/hr or 80 litres a second
Most domestic fan manufacturers publish the fan performance in m3/hr or litres per second (l/s).
The only thing left to consider are:
• Price
• Design
• Noise
• Extra functions e.g. Back Draught Shutters, Run On Timer, Humidity Sensor, Passive Infra-red (PIR) Sensor
Important Note - Building regulations state "in a room with no openable window, an intermittent extract fan should be used with a run on facility set to a minimum of 15 minutes."


Sign In or Register to comment.