Extractor fan pipe under angle

Guessing without looking at the installation of the extractor fan, the best solution would be to replace the existing fan you have currently for the same model, unless it's been installed incorrectly which in that case it's why the fan no longer works, fan manufactures will state how the fan should be installed you will find this information in the manual when you purchase a fan or otherwise you could download a PDF copy and read the installlion guidelines. Plenty fan accross the board are usually installed incorrectly the majority of builders don't tend to read the manuals, it's very important you get a qualified electrician that is registered to complete this task for you.

A few assumptions have to made here. Firstly, the fan to be swapped out is placed on a wall. Secondly, the flexi-tube or rigid flue pipe which connects the fan to the external vent is sloped (wrongly) downward towards the inside of the room therefore causing condensed moisture to flow back into the fan and/or room. Thirdly, the fan may be fitted without a flue and is extracting directly into the solid wall space or cavity wall space. If the client would like a strtonger fan then the standard extraction rate is around 85 cubic metres per hour and they should try to get one with double that extraction rate and when fitted ensure that it is fitted correctly with the correct flue at the correct downard angle going out of the building. Also, must fit an extractor vent which limits the amount of air pushed back on windy days. There is also the possibility of using and in-line fan which sits in a ceiling void or loft space. These tend to be more reliable, stronger and quieter (as the fan is not in the room). As for the claim that it needs an angled fan, I have absolutely no idea what that claim means?

I would recommend a in line fan from Vortice Lineo range.

Each fan has different size outlets common being 100mm Howe ever bigger rooms require more vacuum to clear steam however the size of ducting you use will depend on distant to travel out Oval duct or round will not make any difference what so ever

As a rule I find the straighter and smoother the ducting the better. Flexible ducting is a quick cheap answer but if you place a vac tester on the fan vetura directly on the fan iis up to 20% less using using meters of flexible ducting dangling about in the loft space as opposed to to smooth bore 110mm pipe. Many customers expect to find a "more powerful" extractor but forget manufacturers have to produce a fan that is quiet so have to stay within acceptable margines. As if their fan is too powerfull the air will cause vortexing and even slight back pressure will load the fan and increase the sound levels. Increase the bore size to 150mm and if possible an inline fan unit to remove the sound issue such as a Cyclone unit. But any fan should be able to exchange the air in five minutes to an average bathroom. A Manrose Silent run fan will work perfectly if the ducting is ok.