Inline extractor but where to position, grille to use etc?

[rarara]

I am planning to install an extractor in our bathroom which will go through the ceiling and travel approx 3 or 4 metres to a tile vent. I am going to go for a loft mounted inline version for quietness and performance. Couple of questions though.....

1) Where should the fan itself be positioned along the ducting - 1/2 way, closer to the bathroom etc?

2) If I get a seperate anti-backdraught shutter where does it go in relation to the fan? Maybe some of these fans have their own?

3) What type of grille is needed? Previous surface-fans I have used have had their own grille with removeable facia to clean the dust off. Can I get one like that, approx (12"x9") rectangular? There is an existing hole where previous pipework ran when a false ceiling existed, so I want to utilise that.

 

[stem]

1) Where should the fan itself be positioned along the ducting - 1/2 way, closer to the bathroom etc?

As long as the length of the duct is within the spec of the fan, location doesn't really matter, the total resistance of the duct is the same, but it will be quieter the further away from the bathroom it is. With inclined or vertical duct installations, you will probably have to give thought to a condensation trap though as there is a possibility that condensation could build up in the duct and may run back into the fan, or drip out in the bathroom.

2) If I get a seperate anti-backdraught shutter where does it go in relation to the fan? Maybe some of these fans have their own?

Normally the back draught shutter is on the outlet, but I've not seen a tile vent with one. Some in line fans do have an integral shutter but often a shutter can be omitted where there is a few metres of duct because depending on the orientation of the outlet the resistance of the duct is enough to stop most draughts reaching the room. I have this arrangement in my downstairs WC and never noticed any draught. You could try this and if you did get a draught, install in line shutters in the duct afterwards. You can buy them for under £10

3) What type of grille is needed? Previous surface-fans I have used have had their own grille with removeable facia to clean the dust off. Can I get one like that, approx (12"x9") rectangular? There is an existing hole where previous pipework ran when a false ceiling existed, so I want to utilise that.

Whatever you like really, one that has a large open surface area will offer least restriction and allow maximum airflow. You can even get them with washable filters.