Refrig fan noise FIXED...really

[Skooter]

Originally Posted by idroba

The elbows came from either Home Depot or a hardware store, I don't recall now. The temp sensor on mine is bolted to the refrigerator tube and picks up it's temp from there, not generally the air temp of the compartment. Yours may be different. The main thing I wanted to do was to reduce the overall amount of heat in the upper compartment when running on propane (which I do mostly as I boondock a lot). With less heat there, the quiet fan can keep the temp in check much easier.

My exterior vent cover is metal. I am not sure how this would work with a plastic vent cover.

Kinda dark in there but yours looks similar to our Bambi, except ours might smaller/more cramped. Our sensor is screwed into the cooling fin, so anything that can be done to lower the temps of those fins is worth trying.

Got a Silenx fan on order, as well.

[idroba]

Originally Posted by subfan1

When travelling, does your modification with the 3 inch tubing blow out the pilot flame at speed? Assuming you travel with the fridge on.

No pilot light or low flame level on my refrigerator, it is electronic ignition so the flame is either on or off. Yes, I travel with the refrigerator on.

My 2014 should be the same as your 2012 FC 20.

[Seecue]

Aluminator, you might want to check the original post of this thread, which addresses the question of "pulling" or "pushing" air. The OP's theory, which I used for my fan design, is that the OEM fan installation pulls air from the fins, our the top set of louvers, and right back in the bottom set of louvers, causing a short-cycling of hot air. (This has nothing to do with the fan noise -- it's more "And while I'm at it replacing my fan...")

There are 2 louvered doors on the side of the AS. The top door accesses the fan and fridge fins. The OP's design pulls the air from the bottom compartment -- the one that accesses the fridge circuit board, among other things. The fans then push air over the fins, and out the top louvers. The bottom louvers of the top door are sealed over so the air won't enter there again.

It's a bit more of of a project to install the fans this way, but I figured with the silenx fans I bought, which don't push a whole lot of air, any improvement in the air flow was worth it.

[Seecue]

Excuse me, I meant AlumiTATER!

[Alumitater]

Originally Posted by Seecue

Excuse me, I meant AlumiTATER!

Thanks for those thoughts.....and I did notice most of these modifications were used in trailers which had both upper and lower cabinet vents.....

Guess I was just pondering in my particular application whether pushing or pulling would be most efficient. And I got some very interesting and educational responses....just as I expected from Forum readers! Thanks again. Tom

[Skooter]

Anyone know the CFM rating of the stock fan? (don't think it's been posted yet; sorry if I've missed it) Found a spec sheet of the FP-108 that looks like mine but gives three different versions- 60, 80, and 105 CFM: DC Brushless Fan FP-108/DC, DC fan volume, DC brushless fan speed, DC fan noise level

Just installed the 74 CFM Silenx 15dba w/red blades and it's sooo quiet. But don't think it's moving as much air as the stock fan (105 CFM perhaps??).

[Alumitater]

I have another question....does anyone know a source for the thermal switch which turns the fan on and off as the temp rises in the coolant line?
Thanks in advance.

[subfan1]

Originally Posted by idroba

No pilot light or low flame level on my refrigerator, it is electronic ignition so the flame is either on or off. Yes, I travel with the refrigerator on.

My 2014 should be the same as your 2012 FC 20.

Idroba, I'm going to install the 3 inch ducting on mine, I do have another question. How did you secure the ducting to the boiler tube? I see how you secured the outer part.
Thx

[idroba]

Originally Posted by subfan1

Idroba, I'm going to install the 3 inch ducting on mine, I do have another question. How did you secure the ducting to the boiler tube? I see how you secured the outer part.
Thx

There is no connection to the boiler tube at all. The one strap you see in the photo holds the very light weight aluminum in place. The vent tube just rests on the top of the boiler, with the boiler tube off to one side and open to air from the remainder of the vent. As mentioned in my post, I wanted it to be larger than the boiler vent so additional air could come in the bottom and mix with the heat/gasses to cool them some. That way they would not be so hot when reaching the external vent on the side of the rig. When operating on propane, the gasses from the top of the boiler are very hot. Also, the external vent cover has a screen and slots in it, and the larger vent tube has a better chance of hitting an outlet area.

The one little strap you see has held things in place for about 7000 miles now, the amount I drove last season.

My first trial was with lightweight flex tube, but that did not work out as I could not find a way to hold it in place. The double elbows can be turned and twisted to fit right. I had to remove one or two sections as I recall, to make the length correct. It took some fiddling around.

[BobRay]

Originally Posted by Skooter

Anyone know the CFM rating of the stock fan? (don't think it's been posted yet; sorry if I've missed it) Found a spec sheet of the FP-108 that looks like mine but gives three different versions- 60, 80, and 105 CFM: DC Brushless Fan FP-108/DC, DC fan volume, DC brushless fan speed, DC fan noise level

Just installed the 74 CFM Silenx 15dba w/red blades and it's sooo quiet. But don't think it's moving as much air as the stock fan (105 CFM perhaps??).

On my Norcold 1200, there were 2 OEM fans, 120 CFM each IIRC.

[Seecue]

Originally Posted by Skooter

Anyone know the CFM rating of the stock fan? (don't think it's been posted yet; sorry if I've missed it) Found a spec sheet of the FP-108 that looks like mine but gives three different versions- 60, 80, and 105 CFM: DC Brushless Fan FP-108/DC, DC fan volume, DC brushless fan speed, DC fan noise level

Just installed the 74 CFM Silenx 15dba w/red blades and it's sooo quiet. But don't think it's moving as much air as the stock fan (105 CFM perhaps??).

I'd love to know the answer to this also. My Bambi came with 1 OEM fan, which I replaced with 2 44cfm SilenX fans. Hope I'm pushing enough air come hot weather! Not sure what to expect if I'm not...

[idroba]

Originally Posted by idroba

There is no connection to the boiler tube at all. The one strap you see in the photo holds the very light weight aluminum in place. The vent tube just rests on the top of the boiler, with the boiler tube off to one side and open to air from the remainder of the vent. As mentioned in my post, I wanted it to be larger than the boiler vent so additional air could come in the bottom and mix with the heat/gasses to cool them some. That way they would not be so hot when reaching the external vent on the side of the rig. When operating on propane, the gasses from the top of the boiler are very hot. Also, the external vent cover has a screen and slots in it, and the larger vent tube has a better chance of hitting an outlet area.

The one little strap you see has held things in place for about 7000 miles now, the amount I drove last season.

My first trial was with lightweight flex tube, but that did not work out as I could not find a way to hold it in place. The double elbows can be turned and twisted to fit right. I had to remove one or two sections as I recall, to make the length correct. It took some fiddling around.

PLEASE NOTE THIS UPDATE!! IMPORTANT NEW INFORMATION.

I want to post that in getting the FC out this week I noted a discolored spot on the upper refrigerator vent cover. It turns out that my direct venting of the boiler heat to the outside vent was/is hot enough to damage the clear coat on the vent cover.

So, anyone following in my footsteps needs to be aware of that possible disadvantage. I don't intend to change my system but I sure don't want anyone else to do it not understanding what I have just now found.

[interstateflyer]

We just took delivery of a 2014 International 23D. Our 2013 International 19 had a fan switch near the door. No fan switch in the 23D. The fan fridge fan is crazy loud and stays on for hours even in 58 degree weather. I'd like to install a switch in the fan compartment but I'm not sure which wires to connect to the switch. Can anyone point me in the right direction?

We're leaving for an extended trip in 4 days and don't have time for the dealer to look into the problem. Thanks....sleepless in 23D.

[BobRay]

I would *strongly* recommend against doing that. Many RV fires have been caused by overheated fridges. The Norcold 1200, for example, has had three recalls due to fires. These are propane fires that usually destroy the whole rig and everything in it (including, potentially, you and your family).

What I did on my fridge was to replace the fans with SilenX fans, which are much quieter.

[subfan1]

Disconnect battery
Open fridge door outside
Red wire is the positive
Cut it and connect switch
You will now be able to turn fan off, from the outside door compartment.
Good luck


Sent from my iPhone using Airstream Forums

[SilverGate]

Additional information: adding a fan switch.

[Wayne&Sam]

Yup, quiet fans are cheap and easy to install. Makes a big improvement.


Sent from my iPhone using Airstream Forums

[interstateflyer]

I ordered a SilenX fan today.

I understand that Airstream put a fan switch just inside the door on my 2013 International 19 so that you could turn off the fan while entertaining on the curb/picnic table side.

Funny thing is that the fan noise is much more irritating on the inside than outside. Also, the thermostat in the 19 seemed to turn the fan on at a higher temp than the one in the 23D, so the fan ran much less even in warm weather.

I wonder why after all these years A/S hasn't gone to quieter fans.

[lewster]

Originally Posted by BobRay

I would *strongly* recommend against doing that. Many RV fires have been caused by overheated fridges. The Norcold 1200, for example, has had three recalls due to fires. These are propane fires that usually destroy the whole rig and everything in it (including, potentially, you and your family).

What I did on my fridge was to replace the fans with SilenX fans, which are much quieter.

Adding a fan to an RV fridge has NO EFFECT at all when the discussion turns to fridge fires. They are used to keep the condenser from overheating and degrading the cooling performance of the unit by increasing air flow over the condenser.

I have been directly involved in a few Norcold 1200 fridge fires. These fires are caused by a pinhole leak in the cooling unit, generally located at the boiler (heating) section of the unit. The leak releases highly pressurized ammonia concentrate either directly into the propane flame of onto the hot electric elements at approx. 600 degrees.

The super heated ammonia becomes a highly flammable plasma under 400 psi pressure and causes the ignition. Again, this happens either when operating on LP or electric!

The Norcold recalls focused on installing a high temperature sensor on the boiler tube to remove the 12 VDC from the control board, which then closes the gas valve to HOPEFULLY remove the ignition source.

This recall does NOTHING to mitigate the fire potential when the RV fridge is operating on 120 VAC electric, as a couple of 600 degree heating elements encased in steel tubes and wrapped in insulation retain enough heat, even after power has been removed, to create a combustible environment for the escaping ammonia.

The main point is that ANY cooling fans have NO RELATIONSHIP with any fire mitigation potential.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[interstateflyer]

Originally Posted by lewster

Adding a fan to an RV fridge has NO EFFECT at all when the discussion turns to fridge fires. They are used to keep the condenser from overheating and degrading the cooling performance of the unit by increasing air flow over the condenser.

I have been directly involved in a few Norcold 1200 fridge fires. These fires are caused by a pinhole leak in the cooling unit, generally located at the boiler (heating) section of the unit. The leak releases highly pressurized ammonia concentrate either directly into the propane flame of onto the hot electric elements at approx. 600 degrees.

The super heated ammonia becomes a highly flammable plasma under 400 psi pressure and causes the ignition. Again, this happens either when operating on LP or electric!

The Norcold recalls focused on installing a high temperature sensor on the boiler tube to remove the 12 VDC from the control board, which then closes the gas valve to HOPEFULLY remove the ignition source.

This recall does NOTHING to mitigate the fire potential when the RV fridge is operating on 120 VAC electric, as a couple of 600 degree heating elements encased in steel tubes and wrapped in insulation retain enough heat, even after power has been removed, to create a combustible environment for the escaping ammonia.

The main point is that ANY cooling fans have NO RELATIONSHIP with any fire mitigation potential.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

So then, since the consequence of the fan being off is reduced cooling performance and is not a safety issue, why doesn't Airstream install an on/off switch in every trailer?