Noisy Refrigerator Vent Fan

[rseagle]

The Silenx fan looks like a good solution! Might have to give it a whirl. Sorry about the Pun!

I pose another idea: Could a rheostat (variable resistor) be used with the existing fan to slow the RPMs to a quieter speed? It might be a cheaper alternative then 1 or 2 Silenx fans $26 ea)?

Bob

[dtbw]

The factory fan is a plain vanilla design. The blades are not designed for quiet operation or large volumes of airflow. Slowing it down will cut some of the noise, but it cut the flow of air faster than the reduction in noise. You need a better blade design. As I mentioned, I already replace my factory fan with a lower rpm, high volume design, which made it much quieter inside, but outside sitting under the awning, it was still a nuisance. The key is lots of slower moving, high efficiency blades designed for quiet running. Putting two of these in series may still not result in quite as much airflow as a single unit running at full speed, but the air will be distributed over a greater area, so the result should be satisfactory cooling.

david

[thenewkid64]

Originally Posted by rseagle

I pose another idea: Could a rheostat (variable resistor) be used with the existing fan to slow the RPMs to a quieter speed? It might be a cheaper alternative then 1 or 2 Silenx fans $26 ea)?

Yes, but at the cost of loss of power. depending on the type of variable resistor or Potentiometer you use the loss in voltage is normally done by a resistor that generates more heat. So you get 70% efficiency to be quite but still have the same draw or load on the batteries. If you are boondocking it can make a difference. It will be a lower cost alternative, but as mentioned in other posts you reduce the airflow. The reduction in airflow can make the refer work harder to keep the food cold. I guess what I am trying to say is TANSTAAFL. You are going to have a cost somewhere. So I would go with 2 in series or the quieter fans IMHO.

[Pahaska]

Don't worry about the amount of airflow. The refrigerator is designed to work on thermal currents alone. Any fan at all and any amount of airflow is beneficial. A gale may do as much harm as good.

As important as the CFM of the fans is insuring that he fan is actually causing airflow over the fins. A fan hanging out in free space is pretty ineficient; it may be recirculating more air than it is moving over the fins. I made a baffle out of a piece of aluminum to make the fan more efficient on my International.

[dtbw]

My two silenX fans just arrived. 1st tried powering just one with 12V to see the max noise and air flow. Impressive, quieter yet than the lower rpm, high volume fan that I used to replace the factory fan, BUT there is no doubt that you would still hear it inside, to some extent. From the outside, the whir of the fan would still be noticable and annoying.

Then I put the two in series (electrically)...Virtual dead silence and a combined airflow in line with that producted by the single fan running at 12V. THIS IS THE TICKET to the condensor fan noise issue. Also having the two fans will do a better job of distributing the airflow across more of the condensor fins. I do think that I am going to make an aluminum plenum to mount the fans underneath the condensor and focus the airflow, plus a deflector to go above the condensor fins to direct the flow outwards to the door louvers. This will be vast improvement over the factory "afterthought". The plenum will also give me an area to "sit" the fans on so that I can use the rubber isolation mounts that are included. The isolation mounts, while great for noise, certainly do not offer any mechanical ruggedness, but if the fans are mounted horizontally with the support underneath the fans, then the rubber mounts should work fine.

Even at $55 for the pair (including shipping), this is a relatively inexpensive fix to a large annoyance.

david

[Tin Hut]

David, I look forward to seeing the fans. I need to do the same thing, not for noise, but for heat. I'll need to pick your brain on how and where you wired them into. Thanks.

[rseagle]

David,

Glad you got your fans. I was just out looking at mine. I hope to do the same thing with the Silex units. I'd love to see some photos of your install and plenums that your fabricate. Could you provide a materials list? Also, what size wire will I need to hook up the fans in series. I noticed the 2 DC voltage wires and the red & blue wires pinned to the refrigerator. Is that to the heat sensor? Whill that have to be connected to both fans or will it open the circuit for both?

Thanks,

Bob

[Xray]

The SilenX replacement I just received and installed was a perfect match for the factory fan (i.e. holes lined up). I have not fired mine up yet but am hopeful that it will be "liveable" as-is with only one SilenX installed...

It was an E-Z install.

X

[dtbw]

Bob,

I will take some pics during construction and installation. I have started making the aluminum frame for the two fans to sit into. The plenum will actually just be a three sided affair as I am going to use the back wall of the refrig for the back wall of the plenum.

As for wiring, it is very simple. If you notice each silenX fan actually only has a red and black wire although they come with a harness designed to plug into a PC chassis. You simply cut off the harness leaving only the red and black wires. Then you will connect 1 red wire from one fan to 1 black wire of the other fan (solder and cover with heat shrink tubing). That will leave one red wire and one black wire which will be connected to the existing factory wiring. The factory fan circuti on the A/S is a simple series circuit where the positive first goes thru the on/off switch, then thru the thermodisc and then to the fan. The negative wire is a direct connection. In fitting the new fans, simply attach the red wire to wire leading to the thermodisc and the black wire to the remaining wire from the original install. There will not be any need for any new wire as the existing wires are plenty long.

It should be noted. This type of FAN works only with correct polarity. I am not sure if the silenX fans have reverse polarity protection, but if not, they can be destroyed by reverse polarity. That is why it is VERY important to connect the red wire from the fan pair to the wire from the thermodisc (follow the wire from the existing installation over to the thermodisc).

david

[Xray]

If you can tie your shoe, you can install this resistor.

Simple.

X

[luckydc]

Installed the SilenX with Radio Shack resistor tonight. Quite easy for a non-electrician. Of course, these posts helped!

Quiet, quiet, quiet!!!!!! NICE!!

Dumb question. Is the fan suppose to draw air AWAY from the fins or blow in ON TO the fins? I paid no attention to the old fan. It is suppose to draw air away from the fins, isn't it?

Thanks!

[dkekrksk]

I have a 2004 CCD and I don't have these problems. Did you try working with your dealer?

[dtbw]

A/S installs a power switch accessable from the upper refrig outside (mine is about an inch below the lower lip on the right hand side of the opening. If you have not heard your factory fan, then you need to see if it is even turned on. This issue is not a defect, but rather just the noise that a 12V 4" fan makes. The noise carries into the interior readily due to the way that A/S mounted it, but the fan A/S chose was not one of the quieter designs to begin with.

BTW, I have my dual fan mounting bracket finished and some pics taken. I have not yet installed as the A/S is 15 miles away at its enclosed storage. I also added a switch that allows me to run the fans at half speed (ie in series) or at full speed (in parallel) should the need ever arise. The 2 fans in series are unbelievably quiet and move a large volume of air. I will post pics in the next day or so

david

[luckydc]

A/S does not install a switch for the fan anymore. My 2004 Bambi has a termostat instead.

Can anybody answer my dumb question? The fan draws air away from the fins, right?

Thanks.