fridge coolig fan noisy

[Devocamper]

We are on our first trip with our new host mammoth and loving it adjusting to the downsize from the 35 foot trailer.We are finding that the cooling fan for the fridge is pretty noisy and in the hot weather we are in it runs a lot. I don't think there is anything wrong with the fan it is just a high rpm computer case cooling fan pushing out 75 CFM but when things are quiet it can be annoying. this is the first time we have had a fridge in a slide out all or other trailers had a direct vent to the roof so we have never had to deal with this fan noise. Has anyone come up with a solution I was thinking of mounting two fans with slower rpm and move about the same amount air or a little more but wondered if anyone here had a better idea right now the unit has one 12 volt 92mm 47 sdb (loud)75 cfm fan
Thanks
Mike

[Devocamper]

SidecarFlip wrote:

Devocamper wrote:
thanks for the help , my upper vent cover has two of the rows covered with some sheet metal came from the factory that way so I guess it is to create more flow up higher in the box. I am going to try the two 92mm 50 cfm fans first see how that works should be a direct mount to the current bracket without trying to drill new holes to mount bigger fans . thanks again for the help glad its not just my fridge fan that's a PITA .

Normally with a Dometic fridge with an assist fan or fans in the upper cavity, there will be (supposed to be but not always installed by the camper builder) a curved baffle that goes behind the upper condenser and curves outward and fastens to the substructure of the camper inside the outer wall (If you look at the ARP site pictures, you'll see it and it's in the Dometic PDF file as well. The baffle has to go behind the upper condenser and fasten to the camper substructure. It's purpose is to direct the air flow up and out.

While you are in there (with the covers removed, I'd suggest having a look-see at the insulation between the fridge and the outer cabinet that the fridge is secured to. In my case I had a very minimal amount of insulation (pink glass wool). I went to Lowes and purchased a roll of R15 unfaced insulation, 24" wide and added about 1/2 the roll in the space between the fridge and the cabinet. I used a length of wooden stick to stuff in the insulation (you won't be able to get your hand in there) and I stuffed the space between the fridge body and the outer cabinet on the top and both sides. Every little bit helps. Thin K paid about 8 bucks for the roll. You need to wear latex gloves and a particle mask when you do it however.

In my case I had maybe one third of the insulation needed. Another advantage to stuffing in the insulation is it muffles the fan noise even more.

If you add insulation, have fun and don't get itchy....

Thanks Sidecar I will check both when I get up in there

[SidecarFlip]

Devocamper wrote:
thanks for the help , my upper vent cover has two of the rows covered with some sheet metal came from the factory that way so I guess it is to create more flow up higher in the box. I am going to try the two 92mm 50 cfm fans first see how that works should be a direct mount to the current bracket without trying to drill new holes to mount bigger fans . thanks again for the help glad its not just my fridge fan that's a PITA .

Normally with a Dometic fridge with an assist fan or fans in the upper cavity, there will be (supposed to be but not always installed by the camper builder) a curved baffle that goes behind the upper condenser and curves outward and fastens to the substructure of the camper inside the outer wall (If you look at the ARP site pictures, you'll see it and it's in the Dometic PDF file as well. The baffle has to go behind the upper condenser and fasten to the camper substructure. It's purpose is to direct the air flow up and out.

While you are in there (with the covers removed, I'd suggest having a look-see at the insulation between the fridge and the outer cabinet that the fridge is secured to. In my case I had a very minimal amount of insulation (pink glass wool). I went to Lowes and purchased a roll of R15 unfaced insulation, 24" wide and added about 1/2 the roll in the space between the fridge and the cabinet. I used a length of wooden stick to stuff in the insulation (you won't be able to get your hand in there) and I stuffed the space between the fridge body and the outer cabinet on the top and both sides. Every little bit helps. Thin K paid about 8 bucks for the roll. You need to wear latex gloves and a particle mask when you do it however.

In my case I had maybe one third of the insulation needed. Another advantage to stuffing in the insulation is it muffles the fan noise even more.

If you add insulation, have fun and don't get itchy....

[Devocamper]

thanks for the help , my upper vent cover has two of the rows covered with some sheet metal came from the factory that way so I guess it is to create more flow up higher in the box. I am going to try the two 92mm 50 cfm fans first see how that works should be a direct mount to the current bracket without trying to drill new holes to mount bigger fans . thanks again for the help glad its not just my fridge fan that's a PITA .

[SidecarFlip]

I looked at the ARP unit. Kind of interesting but at least in my case I don't believe it's a needed $135 buck addition. For one thing, contrary to their claim that the snap disc thermostat is installed over the boiler flue exit on that side of the condenser, it's not. Dometic recommends the instillation be on the outboard cooling fin OPPOSITE the boiler, exactly where mine is installed, not over the flue exit and their 2 fan option puts one fan at the bottom of the rear cavity. My opinion (opinion only) is that multiple fans in the upper cavity exhausting through the upper vent pulls ambient air over the entire refrigeration unit anyway.

I do agree with their premise that the addition of an internal (in the fridge section of the internal cavity will go a long way toward cold air circulation inside and eliminate the stratified air in the fridge which will allow for faster cool down and better (more even) interior temps. Easy addition connecting to the interior light. In fact, I bought a small muffin fan just for that modification

[SidecarFlip]

towpro wrote:
Mine has the top hole 3/4 covered by a piece of plywood stapled from the inside. I understand what this is for, but to go into mine from top i need to remove the baffel. It Might be hard to secure it again

But I have gotten used to it. Just finishing 2 weeks at beach and don't hear it anymore.

Mine was too actually, partially blocked upper vent. I removed that and replaced it with a shorter length of HDPE plastic sheet, 1/16th inch thick that just comes up to the bottom edge of the replacement fans.

Mine really blows.... (pun intended)...

[towpro]

Mine has the top hole 3/4 covered by a piece of plywood stapled from the inside. I understand what this is for, but to go into mine from top i need to remove the baffel. It Might be hard to secure it again

But I have gotten used to it. Just finishing 2 weeks at beach and don't hear it anymore.

[GeoBoy]

Mike, I installed an ARP rv refrigerator control with dual fans in my TC because the side vent fridge is not very efficient removing heat. I just completed a 8,600+ mile trip out to the west coast and was up and down the mountains and my fridge stayed at 20 degrees and the freezer was -10. I am very satisfied with the ARP control.

[SidecarFlip]

towpro wrote:
Do you need to pull refreg to do this job?

Not at all. Everything you need to fiddle with is on the backside of the fridge under the access vent covers.

Back in the day before slides, fridges mounted with the lower access vent in the side and the upper vent was on the roof so you had a nice natural draft to keep the cooler ambient air moving (and some slide campers are still like that, fridge mounted on the non slide side.

Once the builders stuck the fridge in a slide, there was no more roof vent so they added fans to artificially create the draft. Now, if they would have used good, quiet fan(s), all would be good but they use the cheapest available and that's not good, but then, they don't have to listen to noisy fans, they just assemble the units.

Even a roof vented fridge can benefit from added airflow, especially in the summer or when the sun is beating down on the side of the camper.

[SidecarFlip]

Devocamper wrote:

SidecarFlip wrote:
Depending on the make of fridge (in my case a Dometic), mine was also noisy for a couple reasons...

One.. I was a cheap fan. There are quite an array of fans available and Dometic uses the cheapest, sleeve bearing fan available. I would suggest replacing it (as I did) with a FDB (Fluid Dynamic Bearing) fan with a computer designed blade. The FDB fans are silent in operation and a computer designed blade will reduce air flow noise. I picked up a couple on Flea-Bay for 10 bucks each, they make no noise whatsoever. But..

Two: You need to pay attention to how the fan(s) are mounted. Just like a FW pump thats mounted solidly to the substructure of the camper, the fan will transmit operational noise and the camper fram will amplify it. You need to isolate the fan from transmitting operational noise/vibration to the camper itself.

I did that by adding rubber grommets to the fan mounts. While it don't dampen everything. between the FDB fan itself and the rubber grommets in the mount, my fan noise is very minimal.

Personally, I prefer not to hear that noise when I'm sleeping at night. During the day not a big issue but at night, I want quiet. Before the modification (new fan(s) and mounts, I was turning off the fridge at night so I didn't have to listen to the fans.

Pretty cheap fix really, just takes some time on your part.

Hey Sidecar thanks and yes the fridge is a dometic with one cheap high rpm fan that runs a lot , the original fan is rated at 75 cfm so I was thinking of putting two 50 cfm lower speed fans in since the bracket is made to mount to 92 mm fans on it , lower speed and a bit more air. I am surprised at how much noise the original fan makes and your right it is a pain at night . I have been researching this since I posted this morning I did not know there were so many types and sizes of these case cooling fans I will defiantly go with the FDB fans , thanks
Mike

Mike:

If you look closely at the mounting bracket, you'll see it's actually 2 brackets, not one (at least in my case it was), so you aren't limited to just the OEM sized fan. I did a pair of 120mm muffin fans and made a second set of brackets from sheet metal (all the brackets are is bent sheet metal). The fans I bought were 2 wire (I cut the plug off the end) rated at 8-13 volts DC so 12 spins them pretty fast but the FDB design is noiseless (and laying on my bench right now, probably headed for the landfill). With the FDB bearings and the computer designed blades, they run quiet. I did do one thing. When I went to 2 fans, I upped the ATO inline fuse to a 2 amp. The stock fuse is 1 amp and both my fans pull a tad over 1 amp, actually 1.2 amps so I increased the fuse size to compensate. I changed nothing else.

My upper access vent isn't readily removable. It's a louvered aluminum grill set in butyl tape and screwed to the outside skin so removing and replacing it is a PITA. Why I upped the fuse rating. The inline fuse on mine is under the upper vent panel

[Devocamper]

towpro wrote:
Do you need to pull refreg to do this job?

Not in my case (Dometic in the slide out) the current fan and the mounting bracket are accessible from the upper removable vent cover. hoping all I need is a ladder and a few wire nuts the bracket is already made for two 92 mm fans
Mike

[towpro]

Do you need to pull refreg to do this job?

[Devocamper]

SidecarFlip wrote:
Depending on the make of fridge (in my case a Dometic), mine was also noisy for a couple reasons...

One.. I was a cheap fan. There are quite an array of fans available and Dometic uses the cheapest, sleeve bearing fan available. I would suggest replacing it (as I did) with a FDB (Fluid Dynamic Bearing) fan with a computer designed blade. The FDB fans are silent in operation and a computer designed blade will reduce air flow noise. I picked up a couple on Flea-Bay for 10 bucks each, they make no noise whatsoever. But..

Two: You need to pay attention to how the fan(s) are mounted. Just like a FW pump thats mounted solidly to the substructure of the camper, the fan will transmit operational noise and the camper fram will amplify it. You need to isolate the fan from transmitting operational noise/vibration to the camper itself.

I did that by adding rubber grommets to the fan mounts. While it don't dampen everything. between the FDB fan itself and the rubber grommets in the mount, my fan noise is very minimal.

Personally, I prefer not to hear that noise when I'm sleeping at night. During the day not a big issue but at night, I want quiet. Before the modification (new fan(s) and mounts, I was turning off the fridge at night so I didn't have to listen to the fans.

Pretty cheap fix really, just takes some time on your part.

Hey Sidecar thanks and yes the fridge is a dometic with one cheap high rpm fan that runs a lot , the original fan is rated at 75 cfm so I was thinking of putting two 50 cfm lower speed fans in since the bracket is made to mount to 92 mm fans on it , lower speed and a bit more air. I am surprised at how much noise the original fan makes and your right it is a pain at night . I have been researching this since I posted this morning I did not know there were so many types and sizes of these case cooling fans I will defiantly go with the FDB fans , thanks
Mike

[SidecarFlip]

Depending on the make of fridge (in my case a Dometic), mine was also noisy for a couple reasons...

One.. I was a cheap fan. There are quite an array of fans available and Dometic uses the cheapest, sleeve bearing fan available. I would suggest replacing it (as I did) with a FDB (Fluid Dynamic Bearing) fan with a computer designed blade. The FDB fans are silent in operation and a computer designed blade will reduce air flow noise. I picked up a couple on Flea-Bay for 10 bucks each, they make no noise whatsoever. But..

Two: You need to pay attention to how the fan(s) are mounted. Just like a FW pump thats mounted solidly to the substructure of the camper, the fan will transmit operational noise and the camper fram will amplify it. You need to isolate the fan from transmitting operational noise/vibration to the camper itself.

I did that by adding rubber grommets to the fan mounts. While it don't dampen everything. between the FDB fan itself and the rubber grommets in the mount, my fan noise is very minimal.

Personally, I prefer not to hear that noise when I'm sleeping at night. During the day not a big issue but at night, I want quiet. Before the modification (new fan(s) and mounts, I was turning off the fridge at night so I didn't have to listen to the fans.

Pretty cheap fix really, just takes some time on your part.