SELECTING THE CORRECT EXTRACTOR FAN SIZE
Selecting the correct size fan is vital for effective ventilation. Your electrician will will be able to help with the selection. If you would like to calculate the size yourself, use the following calculation:
Calculate the Room Volume in Metres:
Multipy: Length of the room x Width of the room x Height of the room = Room m³
Calculate Required Performance:
Multiply the room volume by the number of required air changes. 11 to 15 air changes per hour is a good starting point.
Select Your Fan:
Select a fan with a performance rating at least 20 percent more than what you have calculated. It is better to choose a fan with a higher rating than have inadequate ventilation.
• A domestic bathroom 3m x 2.5m x 2.7m = 20.25m³
• Recommended air changes for a domestic bathroom = 11 to 15
• Taking the higher value – multiply 15 x 18.75 = 303.75m³/hr
• Add 20% = 364.5 m³/hr (364.5 divided by 3.6 = 101.25 l/s)