Extractor fan ducting

thebullsback

I need to replace our bathroom extractor fan.

I'm looking at a manrose MF 100T inline fan which states 100mm inlet and out let .

If i buy 100mm rigid ducting will they mate together or do i need an adapter ?

I know in the past I have used 100mm Flexi ducting on same Fan and it was a real struggle to fit ducting.

Brunokid

Could you give a bit more info about the installation?

Is there to be a grill on the ceiling, duct into the fan then duct to an external grill?

Is the fan going in the loft space or void?

EssexExile

That's what duct tape is for.

thebullsback

Ducting needed from ceiling vent to in-line fan then in-line fan to outside vent.

Current set up uses 100mm Flexi tubing but I would like to use ridget ducting for new install

FreeBear

https://forums.moneysavingexpert.com/discussion/comment/82026771#Comment_82026771

Ah, but the adhesive breaks down after a while. Duct tape (or any other tape) is not a long term fix.

The installation guide for the MF100 series fans are a bit light on details and dimensions. It seems to suggest that hoses are just a push fit, so one would assume that rigid ducting would also slide on. But sod's law says it won't… Fortunately, 100mm rigid coupling are not very expensive, so it may pay to get a couple before fitting the fan.

Lorian

I've fitted several of these with white rigid ducting.

If I recall the MF109T inlets and outlets are spigots and slip inside standard ducting. Ridgid much better than the expanding stuff for airflow. I still tape the joints with proper duct tape.

The don't have back flow shutters so you will likely need to cut one if those in downstream.

Remember you have to keep all the ducting under insulation to stop condensation building up in it and running towards the fan. Ideally it runs under the insulation and down away from the fan but not always possible. Might need condensation trap. Otherwise you'll fill the fan with water.

Also there is a minimum pipe length either side of the manrose, I think it's 0.5m but check

Needs accessible three pole isolator and a 3amp fused connector.

With the T you will need a perm and switched supply.

Very good fans.

thebullsback

Sorry for delay in replying.

Task has now been completed using 100mm Flexi ducting as i have used before . I did purchase some manrose 100mm inline round ducting couplers and a 90 degree bend but they would not fit onto the manrose inline fan because they are 100mm themselves.

seems crazy to me that a company produces a 100mm fitting that does not fit 100mm fan.

Any way job sorted but could have been so much easier and better but for ……. sizing issues

FreeBear

From memory using Manrose ducting (admittedly, the rectangular stuff), the couplings pushed over the pipe.

Are you sure you were using a female to female coupling ?

adrich

The sizing with ducting is an absolute nightmare and drives everyone mad! The issue is that the fan spigot and the rigid pipe are both male fittings (both exactly 100mm outer diameter), which is why they won't just slide together without a female-to-female coupler to bridge them.

Glad you managed to wrestle the flexi duct onto it in the end, though it's always a proper workout for the forearms.