Fridge fan

[Bod]

I'm refiting the galley at present, moved the fridge to its new position, not enough ventilation, no problem, I'll put a fan in the floor to blow cool air from bilge, up the back of said fridge!

 

Got fan (FOC) Ahh. gap behind fridge 100mm, fan 120mm square.

Make up frame to hold fan at an angle to fit space, all good so far, air is blown at the back of the fridge rather than past it.

 

The noise is disturbing! The fan on its own, or in the frame is fine, close to silent.

 

I think the noise is coming from the air rushing up through the holes in the floor, these I have made as big as possible in the frame. ie 85x100mm.

 

Is this likely?

 

Anybody have experince of fitting a fan behind a fridge?

 

Thanks

Bod

[Bill]

I'm refiting the galley at present, moved the fridge to its new position, not enough ventilation, no problem, I'll put a fan in the floor to blow cool air from bilge, up the back of said fridge!

 

Got fan (FOC) Ahh. gap behind fridge 100mm, fan 120mm square.

Make up frame to hold fan at an angle to fit space, all good so far, air is blown at the back of the fridge rather than past it.

 

The noise is disturbing! The fan on its own, or in the frame is fine, close to silent.

 

I think the noise is coming from the air rushing up through the holes in the floor, these I have made as big as possible in the frame. ie 85x100mm.

 

Is this likely?

 

Anybody have experince of fitting a fan behind a fridge?

 

Thanks

 

Bod

 

Slow the fan down a touch (think of the noise a car heater fan makes on the high setting), add a resistor (or variable resistor if you want to be able to tweak the speed) into the +ve feed. You don't need a gale blowing to make the fridge more efficient.

[NMEA]

Slow the fan down a touch (think of the noise a car heater fan makes on the high setting), add a resistor (or variable resistor if you want to be able to tweak the speed) into the +ve feed. You don't need a gale blowing to make the fridge more efficient.

 

 

Make up an attenuator box similar to the ones used in blown air ducts of Eberspachers and Webastos, if they can quieten those down one should work for you.

Edited October 14, 2012 by NMEA

[sueb]

Get a gas fridge?

[Ex- Member]

We have 2 x 100mm fans under tha back of the fridge. I screwed the fans down on to Neoprene rubber strip 6mm I recall into the ply floor not too tight, you can just hear the fans if there's no other noise around, certainly not annoying.

[Keeping Up]

Mine was quite loud until I fitted a rubber strip between the fan and the floor (and remembered on the second attempt not to tighten the screws too much) but the noise was a loud whining hum, not a whoosh of air.

Edited October 14, 2012 by Keeping Up

[nb Innisfree]

I fitted two fans but after a while I realised we weren't running the engine for longer than before and our charging regime was the same, didn't bother after that and opted for a quieter life.

[Bod]

Thanks for the responses.

 

Now the fan is a 4184 NXH 12-28v DC,(237m3/h flow rate) I am running it on 12v, What size of resistor would you recommend?

 

The fan is mounted on 4 rubber anti-vibe mounts, so I don't think it is mechanical noise, certainly the noise only started when the frame was fixed over the floor holes.

 

Slowing down the air flow through the holes by slowing the fan seems the way to go.

 

Bod

[mrsmelly]

Get a gas fridge?

 

Blimey Sue, your as bad as me wiv cassettes

 

Tim

[blackrose]

Get a gas fridge?

 

How do you know he hasn't got one?

 

As long as it's nowhere near the flame I'd have thought a properly fitted fridge fan is equally good for improving the efficiency of a gas fridge as an electric fridge. I'm going to fit one behind my gas fridge.

Edited October 15, 2012 by blackrose

[sueb]

How do you know he hasn't got one?

 

As long as it's nowhere near the flame I'd have thought a properly fitted fridge fan is equally good for improving the efficiency of a gas fridge as an electric fridge. I'm going to fit one behind my gas fridge.

Why make a quiet fridge noisy? Always have a pump out :-))

[blackrose]

Why make a quiet fridge noisy?

 

He happens to have a noisy fan. I'd just change it for a quiet one, but if he manages to slow his fan down it shouldn't be noisy and it will improve cooling efficiency and save fuel - be that gas or electrcity.

Edited October 15, 2012 by blackrose

[ditchcrawler]

We have 2 x 100mm fans under tha back of the fridge. I screwed the fans down on to Neoprene rubber strip 6mm I recall into the ply floor not too tight, you can just hear the fans if there's no other noise around, certainly not annoying.

Same here

[Ex- Member]

You can fit 100mm comp fans almost completely silent running by suspending the fan from 4 corners with short HD rubber bands. Make the access hole 125mm diameter, loop the 4 rubber bands through the holes in the corners of the fan shroud, or drill them out if not there. set 4 screws around the hole proruding an inch above floor level, rig it so the centre of the fan is over the centre of the hole by tensioning the the rubber bands to each of the 4 screws, travers the 12v cable along one of the rubber bands, the fan will hovver over the hole, when running it'll be almost silent.

Edited October 15, 2012 by Julynian

[Old Son]

My boat runs on 24V. Can I buy a 24V computer fan? Does the fan run all the time or only when the fridge compressor switches on?

[Keeping Up]

My boat runs on 24V. Can I buy a 24V computer fan? Does the fan run all the time or only when the fridge compressor switches on?

 

If you have a Shoreline fridge, the fan output is live only when the fridge compressor is running, and it is always 12v even when you are running the fridge from 24v.

[smileypete]

Thanks for the responses.

 

Now the fan is a 4184 NXH 12-28v DC,(237m3/h flow rate) I am running it on 12v, What size of resistor would you recommend?

 

The fan is mounted on 4 rubber anti-vibe mounts, so I don't think it is mechanical noise, certainly the noise only started when the frame was fixed over the floor holes.

 

Slowing down the air flow through the holes by slowing the fan seems the way to go.

 

Bod

Maybe get a cheap PC fan controller, or fit a slower/quieter fan as Blackrose says, for example?

 

http://www.ebay.co.uk/itm/221131927960

 

cheers, Pete.

~smpt~

[Bod]

Maybe get a cheap PC fan controller, or fit a slower/quieter fan as Blackrose says, for example?

 

http://www.ebay.co.uk/itm/221131927960

 

cheers, Pete.

~smpt~

A slower fan has been ordered, and will report back when fitted.

 

I understand how a compressor fridge works, but how does a "Gas" fridge work?

 

Bod

[Bod]

Maybe get a cheap PC fan controller, or fit a slower/quieter fan as Blackrose says, for example?

 

http://www.ebay.co.uk/itm/221131927960

 

cheers, Pete.

~smpt~

Thanks Pete, following your link, I ordered, and have now fitted the slower fan.

 

Loudest noise is now the compressor, a positive whaft of air now goes up the back of the fridge, rather than the gale before!

 

How this will effect the fridge running times, only time will tell, but at this stage all seems ok.

 

Bod

[valrene9600]

If you have a Shoreline fridge, the fan output is live only when the fridge compressor is running, and it is always 12v even when you are running the fridge from 24v.

Are the terminals marked that the fan connects to?. This sounds an ideal way to keep the fridge running less. Is it the black pipework the fan should be pointing at or the compressor?

Thanks

 

Ok I have just carried on reading my search results and found the info on another of your posts/

many thanks

[Bod]

Are the terminals marked that the fan connects to?. This sounds an ideal way to keep the fridge running less. Is it the black pipework the fan should be pointing at or the compressor?

Thanks

 

Ok I have just carried on reading my search results and found the info on another of your posts/

many thanks

Mine is aimed mainly at the black pipes, as that is where the fridge gas loses its heat,after being recompressed.

 

If your set-up is like mine, any extra air flow, will be a good thing!

 

Bod