Condensation Traps

If you’re looking at installing an extractor fan in your home and you plan on venting through the ceiling, there are a couple of things that will need to be taken into consideration.

Firstly, you will need to work out where the fan will eventually vent to the outside world. Ideally, going through either a soffit or gable end wall is preferable as this allows for a low extraction point. Keeping the extraction point as low as possible is important as it will allow the ducting to run at a slight downward angle away from the fan unit, whether you are installing a ceiling mounted axial unit or an inline fan.

This downward run will mean that any condensation that forms in the duct will run away from the fan unit and out of the external grille. This is far more preferable than having water sit in the ducting, causing an obstruction for the air flow, or worse, running back into the fan unit.

However, If a gable end wall or soffit extraction point is not an option, you may find yourself needing to extract vertically out of your roof using a roof venting kit or venting tile. This now poses a potential problem with condensation.

To alleviate this problem, we recommend installing a condensation trap, this will catch any moisture and remove it from the ducting run.

A condensation trap is essentially a collar that is installed in the vertical duct run after the fan unit. The collar is then attached to a 22mm plumbing pipe which can then be either run out of a gable end wall or soffit, similar to a condensate pipe for a boiler, or plumbed into a waste water pipe to allow the run off to drip away.

Condensation traps are designed to be installed with solid ducting rather than flexible ducting so bear this in mind when you are choosing your accessories for your installation.

It is preferable to install the trap as low down the vertical ducting and close to the fan unit to minimise the chance of missing any condensation that might form in the ducting.