Solar extractor fans

[Odana]

First fan question:

I am in need of an extractor fan in one of the vents in my bathroom ceiling, but have been putting it off because getting wiring to it was going to be a hassle. Now I've seen a solar extractor fan in a friend's boat which looks perfect and which he says works very well. I tested it and was impressed. His one cost £30 or so from Mastervolt some time ago, he said, but a quick look on their site reveals nothing. I THINK it worked as extractor out and fan in, but I might have been mistaken

 

What I have seen are these and these (much cheaper). Anyone have any experience of them or have any other recommendations? Can you get ones that work two way (suck/blow)? If so that'd be useful for venting into the boat in summer.

 

 

Next fan question:

I also want to fit a small fan in the wall between bathroom and main cabin to a) extract steam from bathroom and blow the warm air from fire that pools in top corner of main cabin through into the bathroom and the bedroom beyond. There is 12v and (a bit more complicated to access) 240v wiring accessible from where I want to install it. Are there any cheap small (not more than about 10-12cm diameter) two-way fans out there that would be suitable? I can't seem to find anything reasnably priced. Alternatively, how would I set up a computer fan in the hole to work both ways? Would I need 2 fans? I figure I can cover the fans with a small grille to make them look fine and it would work out fairly cheap - just need to work out how to do it! Any advice much appreciated.

[bag 'o' bones]

First fan question:

I am in need of an extractor fan in one of the vents in my bathroom ceiling, but have been putting it off because getting wiring to it was going to be a hassle. Now I've seen a solar extractor fan in a friend's boat which looks perfect and which he says works very well. I tested it and was impressed. His one cost £30 or so from Mastervolt some time ago, he said, but a quick look on their site reveals nothing. I THINK it worked as extractor out and fan in, but I might have been mistaken

 

What I have seen are these and these (much cheaper). Anyone have any experience of them or have any other recommendations? Can you get ones that work two way (suck/blow)? If so that'd be useful for venting into the boat in summer.

 

 

Next fan question:

I also want to fit a small fan in the wall between bathroom and main cabin to a) extract steam from bathroom and blow the warm air from fire that pools in top corner of main cabin through into the bathroom and the bedroom beyond. There is 12v and (a bit more complicated to access) 240v wiring accessible from where I want to install it. Are there any cheap small (not more than about 10-12cm diameter) two-way fans out there that would be suitable? I can't seem to find anything reasnably priced. Alternatively, how would I set up a computer fan in the hole to work both ways? Would I need 2 fans? I figure I can cover the fans with a small grille to make them look fine and it would work out fairly cheap - just need to work out how to do it! Any advice much appreciated.

 

Brushless computer fans are probably the cheapest connected to a largish solar panel. Not sure if computer fans can be made to move air in both directions though.

 

I was thinking of something along similar lines to move air through the boat to reduce condensation when the boat is closed up for the winter.

[Pretty Funked Up]

Not sure if computer fans can be made to move air in both directions though.

 

 

swap the + and - around or tunr it over

[Odana]

swap the + and - around or tunr it over

 

So does that mean that if you want a set-up that can operate in both directions, you need to install two fans (facing in opposite directions). If so, would that impede air flow? Or is there a way of doing this with a switch and just one fan? I vaguely remember a thread ages ago where someone had set up a multi-way set of fans in his portholes, but can't find the link.

 

 

Just to clarify BTW - I am asking about two different fans here - the solar powered one needs to be solar powered and in the roof. The computer fan setup will be inside and can attach to my 12v wiring.

Edited April 16, 2010 by Odana

[RLWP]

So does that mean that if you want a set-up that can operate in both directions, you need to install two fans (facing in opposite directions). If so, would that impede air flow? Or is there a way of doing this with a switch and just one fan? I vaguely remember a thread ages ago where someone had set up a multi-way set of fans in his portholes, but can't find the link.

 

 

Just to clarify BTW - I am asking about two different fans here - the solar powered one needs to be solar powered and in the roof. The computer fan setup will be inside and can attach to my 12v wiring.

 

You need a changeover switch to reverse polarity. Three positions so you can have a centre "off".

 

Richard

[Pretty Funked Up]

a 3 pos. DP/DT switch could be used to do it. I'm sure a handy person on here can supply a wiring diagram

[wonderdust]

swap the + and - around or tunr it over

 

+ - does not work on all fans!

Edited April 16, 2010 by wonderdust

[Keeping Up]

a 3 pos. DP/DT switch could be used to do it. I'm sure a handy person on here can supply a wiring diagram

Happy to oblige:

 

 

 

Edited to add: don't try this with a brushless fan

Edited to add also: We've got a Plastimo solar fan in our bedroom. Works well, but it'd be nowhere near powerful enough for a bathroom. It doesn't have a switch of any sort, it just runs as an extractor 24x7

Edited April 16, 2010 by Keeping Up

[Pretty Funked Up]

yep, make sure you get the right fan (not brushless)

[Glenn&Karen]

Just what I was considering - fitting an extractor fan in the shower in place of the normal vent. In fact was thinking I could fit one INTO the vent on the inside and run off 12v light supply which is next to it. So when light switched on fan comes on for pre-set time. Think the boat builder missed a trick here - would save all that condensation in the shower room.

 

Problem is existing vent has only 95 dia hole in timber frame inside the shower cubicle and cannot find 12v fan less than 100 dia. Any thoughts anyone? Not sure what would be involved in removing the external dome though. (the brass or chrome thingy on the roof).

 

Solar powered may be the answer if it also runs during daylight hours.

[Phil Ambrose]

+ - does not work on all fans!

 

True , I use a brushless 12v fan from Maplins as a galley extractor fan and it will only work one way. We also have a 12v brushless fan to pull hot air from saloon to the bathroom, it works really well. The fans only cost about £6-00 + P&P

 

Phil

 

Just what I was considering - fitting an extractor fan in the shower in place of the normal vent. In fact was thinking I could fit one INTO the vent on the inside and run off 12v light supply which is next to it. So when light switched on fan comes on for pre-set time. Think the boat builder missed a trick here - would save all that condensation in the shower room.

 

Problem is existing vent has only 95 dia hole in timber frame inside the shower cubicle and cannot find 12v fan less than 100 dia. Any thoughts anyone? Not sure what would be involved in removing the external dome though. (the brass or chrome thingy on the roof).

 

Solar powered may be the answer if it also runs during daylight hours.

 

 

Look on Maplin website for brushless 12v fans

 

Phil

[Keeping Up]

Just what I was considering - fitting an extractor fan in the shower in place of the normal vent. In fact was thinking I could fit one INTO the vent on the inside and run off 12v light supply which is next to it. So when light switched on fan comes on for pre-set time. Think the boat builder missed a trick here - would save all that condensation in the shower room.

 

Problem is existing vent has only 95 dia hole in timber frame inside the shower cubicle and cannot find 12v fan less than 100 dia. Any thoughts anyone? Not sure what would be involved in removing the external dome though. (the brass or chrome thingy on the roof).

 

Solar powered may be the answer if it also runs during daylight hours.

That's exactly what I did. I found a 12v computer fan which was an exact fit inside the tube below the vent, and powered it from the light supply (but no timer, it just relies on the light being switched on and off)

 

The solar powered ones aren't usually powerful enough for a bathroom.

[Roger Gunkel]

Computer fan is by far the best idea, as it will move a lot more air than a solar fan, with such a minimal power drain for the time that you will be using it, that you can almost forget it.

 

Roger

[Pretty Funked Up]

You can get a brushless motor to go backwards with a brushless motor controller ( who'd of guessed it )

might not be cost effective but it does do what it says on the tin

 

But a brushed fan would be perfect for the job, harder to find but theyre still out there.

[Glenn&Karen]

That's exactly what I did. I found a 12v computer fan which was an exact fit inside the tube below the vent, and powered it from the light supply (but no timer, it just relies on the light being switched on and off)

 

The solar powered ones aren't usually powerful enough for a bathroom.

 

On the fan I seconded from an old PC (processor cooling fan) it looks like the workings (motor wiring etc) would be open to the steam and water vapour being pulled through the fan.

 

Have you experienced any problems related to this or have you not run it long enough yet to find out..??

[Keeping Up]

On the fan I seconded from an old PC (processor cooling fan) it looks like the workings (motor wiring etc) would be open to the steam and water vapour being pulled through the fan.

 

Have you experienced any problems related to this or have you not run it long enough yet to find out..??

Mine is bigger than a processor fan, I think it's a case cooling fan, and the workings are enclosed. We've not had any issues with it, it's still the same one that we fitted 19 years ago.