Condensation trap in flat channel ducting

[Suburbitonproject]

Installing 90mm by 180mm (150mm equivalent) flat channel duct work for kitchen hood extractor fan. The exit is vertical and the majority of the run will be covered by plasterboard. I will need some way of removing condensation however all the 150 traps I've found are round. Is there a way to fabricate a trap into the flat channel pvc pipe or is there another means to release condensation build-up?

 

[stem]

You can buy rectangular to round adapters, if you get two then insert the condensate trap in the centre, but then I guess your problem is that then it will be too large to fit behind the plasterboard.

It is a bit unusual to fit a condensate trap in a cooker hood duct, because, although there will be some steam collected, there will also be a considerable amount of heat which will normally warm the duct and prevent condensation forming on its surfaces. If you thermally insulate the duct, particularly if it passes through an unheated area such as a loft space or garage, I doubt you will have a problem with condensation.

 

[foxhole]

I would use foil vent in preference to plastic where heat is involved.

 

[Suburbitonproject]

Thanks for the comments Stem. The thermal insulation might just do the trick. The pipe is vertically passing through a roof void hence the concern about condensation, but as you point out it may not turn out to be that big an issue