A box that sucks (a lot of air)

With the box assembeled it was time to make the cuts in the wall.

I sealed of the construction site from the rest of the house with plastic foil. Placed the box in a window of the room I was working in, sealed off the rest of the window with more plastic foil so that there only was an opening for the extrated air and dust.

Then I switched on the fan and began cutting.

Roughly 30 minutes later my door opening was widened and when I removed the plastic foil sealing it turned out that everything has worked out as planned. No dust escaped into the rest of the house, only the actual construction site was contaminated.

The remaining dust was vacuumed away, the box is now waiting in the shed for a possible future use.

Since the old mounting plate of the fan made it unnecessarily high I cut off the excess material with an angle grinder. I made an opening in the front of the box with a jigsaw and fixed the fan in the box with four M8x40 screws and nylon locking nuts.

I dediced to build a wooden box for the fan. Originally I wanted to build a cube, ad a connection for a duct to it and place the box out of the house.

It turned out that the ductwork would be far too complicated and pricy for one use of the entire box, so I just left out the rear wall and decided to place the box on two sawbucks in front of the window.

I used 16mm MDF for the box. The inside of the box is 50 x 50 x 50 cm, so I needed

• 1 plate 53.2 x 53.2 cm
• 2 plates 53.2 x 50 cm
• 3 plates 50 x 50 cm

The plated were assembled using my freshly bought biscuit joiner and Ponal Express glue (which is the de facto standard wood glue among amateurs in Germany).

The fan was originally used in a heating system. The entire hot air based heating system from the 1960s was exchanged in favor of something more modern, but I did not throw away the biggish radial fan. The fan in from 1991, it was made by Ziehl-Abegg and has a 250mm diameter.

Here are details of its modern siblings

Fortunately, the fan can work without all the control electronics from the old heating system by simply connecting it to mains voltage.