Powerful 100mm extractor fan?

Bendy_House

Hi all.

Recently swapped mil's failed 'Primeline PEF4020' ceiling extractor fan for an identical model to make the job easier - which it was. It seems a bit pitiful, tho', and the wetroom in which it's located has a venting tumble drier in it, the idea being that the room is simply 'extracted' as the TD blows in to it.

When visiting recently, tho', and following a TDing, I noticed the room felt very humid even after TD use, with the extractor still running on its timer; there was condensation on pretty much every surface, even some walls. I tried the 'sheet of bogroll close to the grill' test, and found it was pretty weak - my own one will draw the paper up firmly from an inch away, whereas this one had to be practically placed on the grill before it held.

I'll be checking the ducting too, but wondered if anyone has fitted a 4" extractor - ceiling mount or in-line - that impressed them for suckiness?

This one is apparently ~20W, 23 lpm or 85m3/hr capacity.

Thanks. 

EssexExile

I've just fitted a Solar and Palau in-line fan in the bathroom, this one: https://www.tlc-direct.co.uk/Products/SLTD250SILENT.html
250m3/hr. Seems to work fine in our en-suite. I didn't mean to buy such a powerful one but I wasn't concentrating when I ordered it! 

Ganga

Bendy_House said:

Hi all.

Recently swapped mil's failed 'Primeline PEF4020' ceiling extractor fan for an identical model to make the job easier - which it was. It seems a bit pitiful, tho', and the wetroom in which it's located has a venting tumble drier in it, the idea being that the room is simply 'extracted' as the TD blows in to it.

When visiting recently, tho', and following a TDing, I noticed the room felt very humid even after TD use, with the extractor still running on its timer; there was condensation on pretty much every surface, even some walls. I tried the 'sheet of bogroll close to the grill' test, and found it was pretty weak - my own one will draw the paper up firmly from an inch away, whereas this one had to be practically placed on the grill before it held.

I'll be checking the ducting too, but wondered if anyone has fitted a 4" extractor - ceiling mount or in-line - that impressed them for suckiness?

This one is apparently ~20W, 23 lpm or 85m3/hr capacity.

Thanks. 

Does the fan have a jumper in the wiring that you can swop to increase the flow BUT it increases its sound level ,check the specification .

knightstyle

Generally the in-line fans are centrifugal type and are more efficient than the propeller ones so can you fit one? Also it is not good to run an extractor without an open door or grille to allow air into the room.

Bendy_House

Thanks all.

That S&P one should do the job! A bit concerned that Nan is quite frail, and she'll be walking under the grill - any risk? *

No jumper, Ganga - it's single speed.

Cheers, Knight. Looks like in-line could be the way to go if needed, and will also be quieter - I suspended my own one on wires so as not to transmit vibes through the joists. Yes, I think it'll also help to open the door ajar after a while, but I cautioned about not doing this during TDing, as it wouldn't be good to have the very wet air going in to the rest of the bungalow.

Just come back from mil's, and it seems as tho' the issue could have been a one-of. Other daughter had turned up that time with a large load of not-very-well-spun-dry clothes, and the TD had produced a huge amount of warm wet air as a result. When it's just Nan's washing, there isn't that issue, so I might have got away with this one.

* Kidding :-)

fenwick458

how long is the ducting, and what type (flexible/solid)?
if you have fitted an axial fan it's no surprise it's not working, they are designed to push air though a wall, so 300mm though a solid pipe. If it's connected to 3-4m of flexi ducting, there's too much pressure, the fan can't move any air.
an axial fan is one where all the fan parts fit inside the ducting. and a centrifugal fan moves the air around the outside of the fan. bit of an explanation here but it's not domestic based
a centrifugal fan is designed to create pressure and move air through ducting, you can get a surface 100mm centrifugal fan but they are bulky.
if there's loft access a ceiling grill and an inline fan is a much better solution, Manrose CFD200T is 31L/s 
or it's big brother is the MF100T and thats a weapon it's about 70L/s, I've had complaints about the noise they make even when they are in the loft and you can't hear the fan itself, just the sound of the air getting sucked out of the room is quite loud if the ducting run is smooth and short!

molerat

I have the MF100 and agree with the air moving noise (actually have the 100T as it was cheaper at the time but have jumpered the timer as I already have one built into the circuit).  I have insulated it against any possible vibration - 2 pieces of 2 x 1 screwed across the joists with tap washers underneath and the cradle screwed onto the timber again with tap washers.  I find they need pulling out every couple of years for a good clean, all that damp towel fluff really sticks to the fan.  When I fitted it as a replacement a few years back I had to dump the old flexi as it had become a solid felt tube coated in plastic !

Grenage

I know this isn't exactly standard guidance, but at my last place I suspended the fan from the rafters using bungee cords.  No vibrations to be had 

Bendy_House

Grenage said:

I know this isn't exactly standard guidance, but at my last place I suspended the fan from the rafters using bungee cords.  No vibrations to be had 

Pretty much my setup. I can still hear it through the air, but only just.

fenwick458

Grenage said:

I know this isn't exactly standard guidance, but at my last place I suspended the fan from the rafters using bungee cords.  No vibrations to be had 

it's probably again the regs but I don't fasten them down either, I normally just lay them in between the timbers on the insulation, and upside down so the terminals are at the highest point.
fixing in-line fans to the timbers in the loft is a bad idea for 2 reasons, the vibrations get transmitted right through the house, and most are designed with the terminal block at the bottom near the feet so any condensation runs down into them

Chickereeeee

fenwick458 said:

Grenage said:

I know this isn't exactly standard guidance, but at my last place I suspended the fan from the rafters using bungee cords.  No vibrations to be had 

it's probably again the regs but I don't fasten them down either, I normally just lay them in between the timbers on the insulation, and upside down so the terminals are at the highest point.
fixing in-line fans to the timbers in the loft is a bad idea for 2 reasons, the vibrations get transmitted right through the house, and most are designed with the terminal block at the bottom near the feet so any condensation runs down into them

Mine is screwed to a piece of concrete paving, which rests on four feet made of vibration suppression foam (for washing machines etc), onto a timber platform on the joists. Zero vibration/noise transfer that I can detect, apart from the air.