Inline and external range hood blowers

Remote range hood blowers – also referred to as external or inline blowers


The majority of range hoods have the blower located inside of the range hood itself – internal blowers.

Typically a remote blower is called for when a high cfm unit is required because the stove or range dictates it – link to blower sizing.
Exterior blowers are installed either on the roof or an external wall. Installing an external blower directly behind the range hood has limited value in reducing range hood noise – ideally there should be a bend in the duct run between the range hood and the exterior blower and it should be at least 10 feet distant from the range hood.

Exterior blower Fantech

Exterior Blower Abbak

Inline blowers are installed in the duct run – as far down the end of the duct run as possible. These are a great option for efficiency and noise abatement provided an inline silencer is used – the inline range hood duct silencer works in very much the same way as a car muffler does. An important element in inline blower installation is to ensure the ducting is well secured to eliminate duct vibration.

Duct Silencer

Inline Blower

Remote range hood blowers are more efficient than interior blowers purely because it is easier to pull air (as a result of creating negative air pressure in the duct) than it is to push air – this of course pre-supposes that the duct sizing is correct.
Due to structural restrictions, such as a range hood being on an internal wall it is not possible to vent directly outside with a short duct run and less than 2 elbows – no matter what size blower is recommended for the stove it is recommended that a remote blower be used – the reason being of you have a complex and long duct run an internal blower will be very noisy even on the lowest speed setting because today’s high efficiency actually pick up their work rate when they sense high static pressure in the duct run – resistance. This then of course leads to duct size issues – the beauty of remote blowers is that they typically require smaller duct sizes than an equivalent cfm internal blower