Sorry – it’s another Blog post about Condensation.
About 4 years ago we had two in-line Extractor Fans installed by a local electrical firm. After eighteen months both fans failed, and it cost us £300 to have them replaced by the same firm. The cause of the failure was said to be water-ingress via driven rain getting into the fan mechanism. The fans were replaced and draught-excluder shutters put in place to stop water ingress.
Earlier in the week we noticed that the Fans were playing up again – they would either not turn off after the 30 minute time-out, or mysteriously turn themselves on.
So up into the loft I venture again … to investigate the root cause of the issue.
On removing the electrical cover from the first fan I found it was soaking wet – but the body of the fan itself was dry. This could only mean one thing … yes … I bet you have guess it … it’s our unwelcome friend Mr Condensation showing his face again.
The cold of the loft, coupled by the uninsulated ducting had caused the warm air inside the trunking to condense, and that in turn had managed to make a build-up of moisture get itself inside the electronics causing the fans to fail.
I have on order several bales of loft-insulation that I will use to insulate both the ducting, and the fans, to aid in the reduction of a buildup of condensate. What I cannot resolve, is when warm air in the ducting is vented outside (or indeed when cold air blows into the trunking from the outside). If there is another failure I will replace the Fans with a different make – as I suspect the Italian Manufacturer of these fans as part of their manufacturing process take into account the soggy, wet, British climate.
The next two photographs outline the seriousness of the problem. There was a good 25ml of water sloshing about in there. We are lucky that the water ingress didn’t cause a fire.
So armed with my wife’s hair-dryer, in turn I opened up the electrical connections and dried them out as best I could. After moderate application of hot-glue to around the entry point for the electrical connection, this potential passage of moisture ingress has been defeated. The only path left is the wires from the circuit board to the fan motor – my assumption and hope is that the manufacturer had the foresight to make sure these connections cannot conduct moisture.
Then I mounted the fans on a small raised tower to raise it above the level of the exaust hole to remove the possibility of rain ingress, and to allow me in the future to modify the tower to decouple the vibration and noise of the fan from the joists.