# How to turn bad manual exhaust fan into an electric one (video + picture) ?



## lucis (Jan 21, 2017)

Hi all,

I have been lurking for a while and finally decided to join your awesome community to fix this little issue I see no solution for .

The bathroom has a very powerful (too powerful/noisy) centralized air sucking system which can only be opened and closed manually, [ame="https://www.youtube.com/watch?v=6V5iSVS-ZTM&feature=youtu.be"]video here .[/ame]

Now my question is: all the fans I see have, as the name suggests, an in-built fan. 
I don't need that, mine is already too powerful, I need something which one can switch on via a switch (or with a humidity sensor, or whatever mechanized system).



Any idea guys?


----------



## bud16415 (Jan 21, 2017)

Hi and welcome to the forum. 

I cant help you with your problem but others will be along. Do you have more detail on what the thing in the video is connected to?


----------



## Jeffh (Jan 22, 2017)

Appears you have an erv of some sort. Where is the central unit located? That round diffuser is connected behind the wall to some ductwork, trace out where the ductwork goes and you'll eventually find a unit with a fan in it, from there you can plan on re-wiring a de-humidistat/motion-activated/timer switch.


----------



## lucis (Jan 23, 2017)

Thank you guys!

Yes, it's a centralized system for the whole building, using both normally occurring draft I believe and doubling down with a centralized ventilation pump on the top floor. 

Connecting to the top floor pump is probably possible but a bit longer work I believe as there are 3 floors in between (and would need to get the shifty building manager to commit).

So I was thinking of a system which would simply open/close my side of the ductwork, basically as it is now but not manual anymore.
If one can engineer such a thing..


----------



## lucis (Feb 21, 2017)

Thank you guys!

The central unit is at the top of the building (5 floors) and I'm on the 2nd floor, a bit difficult / costly to rewire a switch from there maybe (plus getting approval / help of site admin) ?

So I was thinking of "something" which could open / close the end of my ductwork (10mm hole) but couldn't find anything like that..


----------



## nealtw (Feb 21, 2017)

So you have central whole house air ex-changer?


----------



## bud16415 (Feb 21, 2017)

Most likely the reason it is powerful and noisy is that 90% of the people in the building have also closed their unit off. Now 100% of the air is going out 10% of the holes. 

A system like this is planned as a whole system and that&#8217;s what happens when each person does their own thing. Air con works much the same when in a large office everyone is cold so they start shutting their vents. Next thing you know one guy is working in a wind tunnel. 

I would talk to the condo association or the governing body of the complex and ask them what they recommend.


----------



## lucis (Feb 22, 2017)

That's a very good point and I'll bring the whole issue to the next owners' meeting (unluckily in December) and looks like they already reduced the power as it's significantly weaker now.

On covering the holes though, this is northern Europe, it gets cold in winter, letting warm air out of your house is costly -and unethical for me as it's not good for the environment-.

If you guys have any other suggestion / feedback in the meanwhile I'm happy to read!


----------



## bud16415 (Feb 22, 2017)

You need a certain amount of air exchange in a building to stay healthy. Long winters with no open windows is not good also. Just sucking air out is not the solution though you also need a pathway for new air to enter. Try and figure out why it was designed this way and if that is logical.


----------



## Jeffh (Feb 22, 2017)

Yes you could install a motorized damper. It likely wouldnt be a simple install as you'd need access to around the wall near that diffuser/grille. There may not be enough physical space for moto-damper in the existing wall, so you'd need to expand the wall or add a bulkhead. Also, you would need to run power to it.


----------

