FAQ Ceiling Fans - How is Airflow measured.

Frequently Asked Questions - Ceiling Fans

How is the Airflow of a ceiling fans measured?

In the past we did not measure a fans airflow, we just knew from past experience that a 48inch fan would shift a reasonable amount of air for a bedroom, while a bigger 52inch fan shifted more air and was suitable for a master bedroom or living space.  We then saw 56inch fans come about which suited alfresco areas and larger living spaces. We also knew from experience that metal blades shifted more air than timber blades so we also took that into account.

Nowadays there are 3 blade, 4 blade and 5 blade fans, Fans with timber blades, ones with metal blades and even plastic moulded blades, not to mention all the different sizes from 900mm fans right up to 2400mm fans so we needed a more accurate way of comparing the fans performance.  Fans are now measured in "Cubic meters of air per hour" (cbm/hr), but what does that mean to the ordinary customer?

At Tillys we like to use this as a comparison to explain the airflow measurement. The standard fan that has been sold for many years for bedrooms was a 4 bladed timber fan with a blade size of 1200mm or 48inches.  This sized fan more than likely moved about 7,000 - 8,000 cbm/hr.  A 52inch (1300mm) model fan of the same design managed a bit more air movement at about 9,000 - 10,000 cbm/hr so this was pretty adequate for a typical bedroom.

We find that any fan with over 10,000 cbm/hr is performing quite well and will suit any living space, and for comparisions sake the largest 1800mm - 2400mm ceiling fans we sell can get up to 24,000 cbm/hr.  Hopefully this will help you understand the amount of air you might be looking for in a ceiling fan.