2nd Bathroom Extractor Fan can we spur off existing?

[compact]

Hi the existing wall mounted extractor fan doesn't really clear the room when we shower so thinking of fitting one directly above the shower.
Can we spur off the existing fan wiring?
Will the switch fuse handle both?
Two might be excessive and we get rid of the original, but would be interesting to see how 2 compare to 1 and how just the new one directly over shower compares.

Thanks

 

[flameport]

Can we spur off the existing fan wiring?
Will the switch fuse handle both?

You can and it will - but two extractors in the same room will not work in the way you expect.

 

[Taylortwocities]

Electrically you can. The average fan is about 20watts so less than a light bulb.
But, seriously, if the fan isn't clearing the room, you should look at why that is: Check

• You have a duct of perhaps 4" diameter. Can the same amount of air enter the room? otherwise the fan is trying to create a vacuum
• Is the fan powerful enough? Many fans are cheaply made and just do not have the grunt to pull air much more than through a wall. use a centrifugal fan rather than an axial one.
• Is ther a long duct, is it smooth, or corrogated.
• Is the fan or the duct clogged up with fluff, gunk or other detritous
• Are there backdraft flaps that are jammed shut
• Is the fan a timer one that runs on after the light goes off. Calculate the room size and the fan throughput, maybe it needs to run on for quite a long time to change the room air. Use this calculator https://www.tlc-direct.co.uk/Technical/Ventilation/Ventilation4.html

And others that i cannot think of at the moment

If you have a second fan then be aware that the two will fight each other, if they are not balanced then the more powerful one will suck air into the room back through the weaker one.

 

[sparkwright]

Is the existing fan 12v or 230/240v?

 

[mwatsonxx]

Don't wait for the forum wafflers to start, TTC has given you all the correct info you require

 

[compact]

Thanks Taylor,
You hit open the 1st and most obvious, air can't get in. The extractor is next to a window and opposite the door. Would you leave the door open a jar to create air flow?
I'm not sure how powerful it is, it has "Istok" on it but can't find it online.
It's only 6 months old vented directly out through the wall with the flexible piping.
The flaps are working OK.
The fan is on a separate switch so we leave it on.
Thanks

 

[Taylortwocities]

OK, so obv thing is to prop the door open a bit and see if that does the trick.

 

[JohnW2]

OK, so obv thing is to prop the door open a bit and see if that does the trick.

Indeed - and if it does do the trick, then trim and inch or so off the bottom of the door.

Kind Regards, John

 

[banjodeano]

i have just fitted one of these
https://www.screwfix.com/p/manrose-mf100-25w-100mm-mixed-flow-fan/26867
i swear it would suck a golf ball through a hose pipe

 

[Iggifer]

i have just fitted one of these
https://www.screwfix.com/p/manrose-mf100-25w-100mm-mixed-flow-fan/26867
i swear it would suck a golf ball through a hose pipe

Not particularly useful when the OP clearly has a wall mounted fan, but yes they are damn powerful

 

[JohnW2]

Not particularly useful when the OP clearly has a wall mounted fan, but yes they are damn powerful

Maybe it's just me, but I have to wonder about the 'energy consequences' (in the absence of heat recovery) of powerful extractor fans. .... If that one could do what it says on the tin (245m³/hour) then, by my reckoning, it could probably completely remove all of the heated air in an 'average house' in about 30 minutes.

Kind Regards, John

 

[ban-all-sheds]

Aside from saving energy (not, I stress, a bad idea), tightly sealed houses cause more problems than they solve.

 

[cwhaley]

Aside from saving energy (not, I stress, a bad idea), tightly sealed houses cause more problems than they solve.

Completely agree. It was a strange concept to us at first, but we are now used to keeping some windows ajar (and locked) during the working day -- even during the coldest winter days. Yes the house is fairly cold when we get home, but the whole house has had 8-10 hours of good ventilation and we haven't seen a spec of mould or condensation anywhere since doing this. I don't see the point in keeping it warm during the day if nobody is in.

 

[compact]

The door ajar has helped, so will keep an eye on how it goes. I was concerned that condensation around the edges of the panes, on the wood windows may eventually affect the frame.

 

[Seb101]

Not particularly useful when the OP clearly has a wall mounted fan, but yes they are damn powerful

The timed version of this fan (MF100T) is currently available on Amazon for £46.70 (with Prime delivery). Absolute bargain.
https://www.amazon.co.uk/Manrose-MF100T-Mixed-Extractor-Ducting/dp/B01G8DM5UA