Size is based on room volume, not floor area. Measure the length, width and height of the room in metres and multiply them together, then match a fan that can change that volume of air over several times an hour. Most fans on this page carry their extraction rating in cubic metres per hour (m3/h) in the product title, so you can compare them directly: ratings start around 85 m3/h and reach 3,460 m3/h on the largest roof fan, with most bathroom and laundry ceiling fans sitting in between. Some models quote litres per second (l/s) instead. Rather than guessing, put your room dimensions into the exhaust fan calculator and it will give you the extraction rate to aim for. If the room has a high ceiling, an enclosed shower, or a long duct run to the outside, size up rather than down.

It depends where you're placing your fan however most will be IP rated since their purpose is to draw out moisture, so by definition they will be in a high moisture zone.

Yes. Fan noise is quoted in decibels (dB), and a lower number is quieter. The quietest option is usually an inline fan, because the motor sits up in the ceiling cavity rather than in the room with you. If you would rather have the fan in the ceiling itself, look for a model that publishes a low dB figure on its product page, since not every fan quotes one. Browse our inline fans to compare the quiet options.

An inline duct fan is a type of exhaust fan where the fan mechanism is built into the ducting, usually along the tube so that it sits in the roof cavity. As such, with an inline fan, you would not normally see the fan through the ceiling vent. They are a popular option for homes with limited space above the ceiling.

Fan ducting will often outlive the fan its connected to but thankfully it is usually possible to find a fan that is compatible with your existing ducting. The diameter of the existing ducting and the fan's duct connector, and the airflow of the fan are two key considerations. The easiest approach is to choose a like for like model from the same company as the original fan, but we would always recommend checking with a product expert. If you need help, please send us a message with as much detail as possible and we'll do our best to help.

Firstly, don't worry, you're not alone. We have many clients come to us who have limited space above their ceiling for an exhaust fan. Most exhaust fans will need at least 175mm of height about the ceiling (in the cavity) however there are some low profile options available, such as in our filtered collection here. In this collection you'll also find wall mount and inline fans which are a great solution for limited space. If you need further help, please get in touch and we'll be able to advise you on the best approach.