I have a shower extractor that goes in to the loft, so when it is cold it has a lot of condensate that can drip back through the extractor. Not pleasant when cold condensate lands on you while in the shower.

I couldn't find a trap designed for 100mm duct so I designed my own to use with a few other duct fittings.

Specs:

Duct should be 100mm ID with 1.6mm wall and OD of 103.2mm.

If using on an inline fan, fan OD should be 98.5mm.

Condensate outlet is based on 21.5mm. I have designed it to go straight into an elbow or Tee. These fitting seems to varying in size a little as I have an older one that is tight and the newer ones are loser on the pipe. I have designed it to be a snug fit on the newer ones, so the outlet is 21.8mm

Model sizes:

To go in to duct 99.6mm

To go over duct 103.6mm

To go over duct fitting 100.3mm

To go over fan 99mm

Printed on strength so basically all solid walls apart from the stop and drain area.

Hope someone can make use of this.