I just had a new dryer installed.

The installer said I needed to buy a pipe reducer because the dryer vent duct and the exhaust pipe are both 4". He cut some holes in the dryer vent duct to fan it out and taped around it but said it will leak air and lint until a reducer is added.

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Will this reducer work?


Or should I buy something else? Thank you.

3 Answers 3


At the least, buy this.

The reason it is the least, is lint will still get trapped in the edge that goes into the flexible part. Joints should be placed so the moving air flows over the joint, not into the joint. The reducer you have at first will restrict the flow, and still have the joint facing in the wrong direction, although you would not need to cut the flexible pipe.

The corrugated ends of the piece I linked to will fit inside each end of the vent pipe and the flexible duct, and minimizes restriction. It would be best if the flexible pipe was reduced in the same way, then the air would flow over the joint the proper way. There is a tool to do that reducing, any duct man worth his salt has this.

enter image description here

  • Thank you! Also, what do you think about this duct with collars? homedepot.com/p/205046888
    – Ryan
    Commented Feb 8, 2018 at 16:43
  • 1
    Perfect, that will do the trick, replacing the original pipe from dryer to vent.
    – Jack
    Commented Feb 8, 2018 at 16:45
  • 1
    @Ryan The product you linked to above, is exactly what you want to buy. The smooth end should fit over the pipe coming out of your dryer, and the crimped end should fit into the pipe in the wall.
    – Tester101
    Commented Feb 8, 2018 at 17:18

No, that is the wrong size. Measure the outside diameters of both pipes and head into the store. I don't think you need a reducer, you need a connector because both the pipes look very close in size to each other. Measure the connectors physically in the store.


The person who installed the duct work in the wall put the wrong end facing you.

For 4" dryer vent, the flanged side always points AWAY from the dryer and the smooth side always points TOWARDS the dryer. It's relatively easy to fix this from the dryer to the wall (get a new section of pipe) but it's much harder to fix it in the wall.

  • That makes sense - thank you. The duct work was installed about 30 years ago. This wasn't the first thing I've learned of that was installed incorrectly lol.
    – Ryan
    Commented Feb 8, 2018 at 23:27

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