Date: Mon, 29 Aug 2016 08:47:11 -0600
Reply-To: Steve Williams <steve@WILLIAMSITCONSULTING.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Steve Williams <steve@WILLIAMSITCONSULTING.COM>
Subject: Solution - Re: Dometic fridge (external) fan replacement...
In-Reply-To: <5e1dc97d-70b4-e1e7-eb6e-ebf6cd5a3602@williamsitconsulting.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Hi,
I used the approximate specifications from the GoWesty fridge fan
replacement & bought a 120mm computer fan from my local computer store.
I went for a good quality, quiet fan with slightly less cfm's than the
GoWesty fan. Theirs is 85 cfm & I got a 78 cfm fan (to get something
very quiet - 27 db and a "reasonable" current draw - 0.16A, 1.92W.
Other people have mentioned the computer "muffin fans". They come in so
many sizes/capacities the "muffin fan" designation was a bit ambiguous
which was bothering me.
Thinking about volume... 75 cubic feet of air seems like a reasonable
amount of air to be moving! That's almost 3 cubic yards of air moved
per minute (assuming no restrictions). The fan I got was a 4 wire fan
and after a bit of research found that pin #1 is ground, pin #2 is +12v
and the other 2 pins are for speed control & speed sensing (feedback to
a computer which I don't care about).
I butchered an old power supply to get a piece of tin with a big round
hole in it to make a 90 degree bracket. I used the same mounting holes
as the original fan but made the bracket the full width of the fan. I
isolated vibration sensitive components as much as possible using bike
innertube rubber. I did use 2 screws to attach the fan to the bracket &
2 of the rubber isolation mounts that were included with the fan. I
didn't like the idea of having 4 corroding piecies of rubber in the back
of the fridge so compromised with 2 screws.
The fan does stick out a bit from the back of the fridge, but given it's
the same size as the GoWesty one, I'm hoping it all fits back in :)
I've washed all the fins & waiting for everything to dry.
I also opened up the combustion box and cleaned it out. It wasn't in
too bad of shape. I also removed the jet & tried to clean it, but it's
such a TINY jet, I really didn't do that great of a job. Just poured
some solvent through & flushed with brake cleaner & compressed air.
Here's a photo to how I set the fan up. The photo is hosted on my home
server so might be a bit slow to load... not the "instant" Internet we
are all so used to :)
http://www.williamsitconsulting.com/misc/DometicFan.jpg
Thanks for everyone's input. At a bare minimum, I won't be woken up in
the middle of the night by a squealing fan :)
Cheers,
Steve Williams
http://www.williamsitconsulting.com/misc/DometicFan.jpg
On 28/08/2016 12:08 AM, Steve Williams wrote:
> Hi,
>
> The fan on my Dometic fridge started squealing quite loudly when it
> starts up. Not so great in the middle of the night ;)
>
> I am just going to replace it with a computer fan. I've got a few old
> PC's that I can butcher. I figure I can cut up the metal from a power
> supply to make a suitable bracket. Looking at the orientation of the
> existing fan, I'll have to make a 90 degree bracket which isn't too
> challenging if I use a power supply to cut up.
>
> I can't be the only person that's had to do this. What size fan (cfm?)
> did you use? What RPM did you use? I'm going to try to find a fairly
> quiet fan, but really don't know what the cooling capacity should be.
>
> Thanks,
> Steve Williams