Foam box 250 m³

An extraction box rated 250 m³/h in a moulded foam housing, with a centrifugal fan inside and a lining of acoustic dimpled foam. 125 mm flanges at inlet and outlet.

Why a housing made of foam

The housing is EPP, expanded polypropylene. That is the same class of material as the protective insert in a tool case or a cycle helmet: small closed foam cells fused into a single shape.

For a fan housing that combination of properties is a lucky one. The material is light, being mostly air. It is stiff enough to form a case that holds its shape. And because the cells are closed, it takes up no water and does not grow mould.

The point here is damping. A vibration that sets a hard panel ringing disappears into foam: the cells deform, rub against each other and turn the movement into a trace of heat. Steel passes vibration on; foam eats it.

EPP also has a memory. Press a dent into it and the shape largely returns. A steel case that takes a knock keeps the dent, and a dented fan housing is one that rattles.

The material works from -40 to 100 °C, well outside anything a grow room does, and it is recyclable.

What this size handles

250 m³/h is the smallest in this range. At roughly twenty five air changes an hour that suits a space up to around 10 m³, so a large cabinet or a small grow room. The connection is 125 mm, matching the usual ducting and filter sizes at that scale.

Technical Specifications:

• Housing: EPP, expanded polypropylene
• Fan: centrifugal
• Insulation: acoustic dimpled foam
• Capacity: 250 m³/h
• Flange in and out: 125 mm
• Temperature range: -40 to 100 °C
• Weight: 4.5 kg
• Dimensions: 32 x 32 x 38 cm

Frequently asked questions

Is foam not fragile?
EPP is stiffer than it feels and springs back after a knock. It is not the same material as polystyrene packing.

Can I run it on a controller?
Yes, that is usual for this type. At lower speed both the noise and the capacity drop.

Where do I put it?
On a level surface or suspended, with the ducting as straight as possible at both ends.