Metal box 250M³/H

An insulated fan box in hot-dip galvanised steel with a Torin blower inside, rated 250 m³/h. Complete with 125 mm flanges, hanging hooks and a plug.

What a scroll blower is

The fan in this box is not an inline fan but a centrifugal one, known in Dutch as a slakkenhuis after the snail-shell shape of its casing.

It works differently from a propeller. Air enters at the centre, is flung outward by a spinning impeller and gathers in a spiral casing that widens towards the outlet. That spiral is the scroll, and its shape converts speed into pressure.

Which is why boxes use this type. An extraction system with a carbon filter on it works against resistance, and under resistance an axial fan's output falls away quickly while a centrifugal holds on far better. A scroll blower is built to push air through something, not merely to move it along.

The price you pay is space: the spiral shape does not fit inside a duct, so it needs a case. And noise, since the impeller makes more of it than a propeller. Both are answered here by the case around it, which is lined inside and keeps the sound in.

Technical Specifications:

• Case material: hot-dip galvanised steel
• Fan: Torin scroll blower, centrifugal
• Insulation: fully insulated case
• Capacity: 250 m³/h
• Power: 30 W
• Inlet flange: 125 mm
• Outlet flange: 125 mm
• Included: flanges, hanging hooks and plug

Frequently asked questions

Why not simply an inline fan?
Because a scroll blower holds its capacity far better once a filter and a long duct are attached.

Can it run on a controller?
Yes. Note that a fan at lower speed can vibrate more, which is what the softbox version addresses.

Does it come with a plug?
Yes, the box is supplied complete with plug, flanges and hanging hooks.