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mstephens · 12-23-2012, 03:21 PM

2012 Flying Cloud 25 (rear bedroom).

On the street side I have two grill hatches for the refer access. Behind the top hatch is a 6" 12V muffin fan mounted to the hatch opening. It is wired to a thermocouple which is hastily screwed into the finned heat sink at the top of the fridge. I say hasty because A) several fins are bent; B) there seems to be a .050" gap of sorts between the thermocouple body and the fin. (Usually thermocouples are mounted with silicone heat compound).

The problem is in two parts:
1. The fan runs about 90% of the time that the fridge is operating. Doesn't matter whether operating on 120 or gas.
2. It is LOUD. I mean really loud. In a campground you can hear it 30 feet away. Partly because it is mounted to the aluminum skin, and partly because it is a lousy brand of muffin fan with a very noisy operation.

Now then.....When I touch those heat sinks, they aren't even really warm, let alone hot. Maybe 40C? Something like that. Nothing inside that compartment feels very hot. The pipes carrying coolant get a bit hot sometimes, but oddly not where they run through the heat sink.

Questions:
1. Does anyone have this model, with the fan - and how does it work for you? Run a lot? Quiet?

2. Anyone replaced this (dealer or self) for being defective?

My suspicion is that the thermocouple is either blown, installed wrong, or is the wrong temperature. I could maybe see it coming on at 100C on the heat sink, but 40C?

Right now (at camp) I disconnected it to get some quiet.

JDS · 12-23-2012, 03:55 PM

I have a 2011 23' Int'l. and the fridge fan runs FOREVER when I switch the fridge off. It's loud, in my opinion, but probably not as loud as yours, based on your description. I'm not really shedding any light on your issue, just wanted to vent about how long that sucker runs on after the fridge is turned off.

John S.

mstephens · 12-23-2012, 04:33 PM

Quote:

Originally Posted by JDS

I have a 2011 23' Int'l. and the fridge fan runs FOREVER when I switch the fridge off. It's loud, in my opinion, but probably not as loud as yours, based on your description. I'm not really shedding any light on your issue, just wanted to vent about how long that sucker runs on after the fridge is turned off.

John S.

Good information. I suspect based on your comment, that this thermocouple is active to a very low'ish temperature. I would think 100C would be perfectly useful. It seems to be much much lower than that.

When I get home, I can remove it and find the part number. I don't want to tinker while I am 2700 miles from home base.

TG Twinkie · 12-23-2012, 04:47 PM

The part you are referring to is a Thermostat, not a thermocouple. 100C might be a little high, since it is equal to 212 F.
You could install a resistor in series with the fan motor to slow it down."

Wayne&Sam · 12-23-2012, 04:48 PM

Loud fans have been a problem for a while. Some folks replaced the fan with a quieter one. I did and it's better, but I still get a louder harmonic inside the trailer.

overlander63 · 12-23-2012, 05:07 PM

We've replaced a couple of the fans under warranty, and the replacements aren't much, if any, quieter. I have tried a resistor, but to slow it down enough to make it quieter means it is too slow to move enough air. One of my co-workers found a piece of dense rubber foam with sticky stuff on one side, and we removed the housing, put the foam between the housing and the door frame, then reinstalled the fan, with much better results. We are only allowed to replace on kind under warranty, but the computer fan I have for my fridge is so quiet you almost have to stick your finger into the blades to see if it is running. Replacement fans are inexpensive enough you can pull yours off and take it to a computer shop to get a better, quieter one, and not be out much more than the price of amfast food lunch.

mstephens · 12-23-2012, 05:07 PM

Thermostat...I see. When I hear that word, I think of something adjustable. Is this device adjustable?

I'd like to exactly what is being cooled by this fan. It blows outward through the hatch, which seems to be a very inefficient means of cooling anything (lots of resistance).

There's the space itself of course. There are some pipes for the coolant and there is that finned sink.

I'm guessing this fan is trying to vent the space in general down to X deg, and apparently X is rather a low number? (When I pulled in, the air temp was 62F and nothing in that space felt like more than say +20F above ambient. Pretty sensitive, isn't it?

One would think that the fan ought to be at the bottom and be sucking in fresh air to go out the top, if the object is to cool the space?

Just thinking out loud.

mstephens · 12-23-2012, 05:17 PM

Quote:

Originally Posted by Wayne&Sam

Loud fans have been a problem for a while. Some folks replaced the fan with a quieter one. I did and it's better, but I still get a louder harmonic inside the trailer.

Oh boy. I see a treasure trove of information about this fan issue. Ha ha - I might have known! Great stuff and it looks like there are plenty of fixes available.

Phoenix · 12-23-2012, 09:37 PM

This is an old problem. See threads below for replacement fan(s):

http://www.airforums.com/forums/f425...ml#post1191250

http://www.airforums.com/forums/f425...ml#post1191357

Also, a search of this site will provide additional links to other threads on this subject, where others have used alternate products and methods to address this problem.

mefly2 · 12-23-2012, 10:17 PM

No fan switch?

Phoenix · 12-23-2012, 10:52 PM

Our 2005, 19-foot Bambi has a factory-installed fan switch just inside the door, low and to the left, just above the fire extinguisher. That switch turns the power OFF and ON to the fan, but the thermostat on the exterior coils (top vented door) actually controls when the fan runs (when the power switch is ON).

Not sure where the switch is on the 20-foot Flying Cloud.

mstephens · 12-24-2012, 04:15 AM

Quote:

Originally Posted by mefly2

No fan switch?

Well, you certainly made me look - but no, I don't have a fan switch on mine.

overlander63 · 12-24-2012, 06:37 AM

The new models have no switch, but one is easily added. Least complicated spot is next to the fan.

TBRich · 12-24-2012, 09:03 PM

I don't think the switch is connected to the year, but rather the model...as far as I know, only 19'ers have an on/off switch for the fan inside for some reason. It may have to do with the type of fridge...ours does not vent through the ceiling like a 25' frig does (and those models with larger refrigerators). A friend's 22' with an even smaller frig under the counter does not have a switch and friends with a 23' with a larger frig don't either.

The purpose of the fan is to act as an exhaust fan to pull air through the fins and out...but the original fan and location is very inefficient. We replaced ours with Snyder fan kit...a funnel affair with the fan at the base (yellow rectangle in pic #1) the brings the air in from the bottom and pushes it upward through the fins...the thermostat was originally connected to the fins (green circle in pics #2) but the tech installing it moved it to the pipe (blue circle in pic #2) for a better location for temps. We have since had to replace the fan again. It is still louder than I'd like it to be but it's much better. We typically turn it off at night, as in our area it runs quite a bit of the time.

If you want to add a switch to yours, you can easily do this inside the compartment.

Aage · 12-24-2012, 09:23 PM

Quote:

Originally Posted by TBRich

The purpose of the fan is to act as an exhaust fan to pull air through the fins and out...but the original fan and location is very inefficient. We replaced ours with Snyder fan kit...a funnel affair with the fan at the base (yellow rectangle in pic #1) the brings the air in from the bottom and pushes it upward through the fins...the thermostat was originally connected to the fins (green circle in pics #2) but the tech installing it moved it to the pipe (blue circle in pic #2) for a better location for temps. We have since had to replace the fan again. It is still louder than I'd like it to be but it's much better. We typically turn it off at night, as in our area it runs quite a bit of the time.

If you want to add a switch to yours, you can easily do this inside the compartment.

Personally, I think that a heat-controlled on-off situation would be more effective; a thermostat with built-in switch. I seem t remember someone installing that set-up, but can't recall who posted it or where they posted it.

Also, the Snyder kit is, I feel, a brilliant way to promote cooler air from the bottom of the cabinet to blow over the fins, but if quiet enough fans were used, a pair of them mounted at, near, or in the roof exhaust would ensure that max cooling would occur in the hotter summer days.

In that situation, I think the thermostat solution (and super-quiet fans) would be even more desirable.

TBRich · 12-24-2012, 09:35 PM

Well I think you are right, Aage...our rig has BOTH the automatic thermostat in the actual compartment AND the off/on switch inside...if the inside switch is "on" the fan will then go on and off via the thermostat control at the back of the unit. Like I said, our frig doesn't vent through the roof, so it has to blow the hot air a right angle out the curb-side vents...maybe that's why there is a double system...not sure of the rationale, really. I do like being able to turn it off completely from inside, though, when the hum is bothering my sleep. When I have to replace that fan again, I am gong to make a better effort to get an even quieter one...

dkottum · 12-24-2012, 10:25 PM

We have exactly the same trailer as you. Just get a little inline switch (the little plastic things with the little rotary switch) and cut the wire to the motor. Put the switch there (a 2 minute job), and turn it off most of the time. Except maybe when the temp indicator on the fridge is too high, and that would be on very warm days when the outside fridge compartment is in the sun.

When its warm out, prop open the upper and lower outside vent doors so plenty of air will move through the area. Close them if rain is forecast. We have been in our trailer for last two months and have not switched on the fan at all, just keep an eye on the fridge temp guage when it's hot out.

I have been told a full fridge and freezer will stabilize the temperature, so if things get empty, we have put a couple plastic jugs of water in there.

doug k

mstephens · 12-25-2012, 04:45 AM

If it comes with a switch from the factory on some models, one wonders that the instructions for use would be?

I see some mention of monitoring temperature of fridge. The inside temp? Mine has an LCD on the front which reads 42 to 45 depending on the setting. It doesn't seem related to the fan operation, but I could be wrong.

I wonder what the thermostat is reading? The temp of the fins themselves, or is the fin simply a mounting surface, and the thing is reading the air temp inside the cabinet?

I guess one thing I am picking up is that this fan is obviously not crucial, since it can be turned off on many models. I'll have to dig into what that thermostat IS, and what temperature it is working on and so on. Then, find a nice quiet fan and so on.

Good comments from everyone - much appreciated.

CountryBob · 12-25-2012, 08:53 AM

I have had two airstreams and after finally replacing the thermistor I chose to put in a switch and while doing that I wired in a large resistor in series with the switch (which reduces the rpm) and eliminates the noise. I picked up the resistor at Radio Shack. You may have to pick up a couple to see which one fits the bill. By the way while boondocking the switch helps because I do not want the fan running at all.

Wazbro · 12-25-2012, 10:39 AM

Quote:

Originally Posted by mstephens

Mine has an LCD on the front which reads 42 to 45 depending on the setting.

The ideal refrigerator temperature should range between 35°F to 38°F. You really don't want it over 40°F if you don't want your food to spoil.

They are talking about the temp in the fridge going up from where it is set or not being able to cool enough.

The cooler it is in the compartment behind the fridge the more efficient the fridge will dissipate heat.

The hotter it is the fridge uses more energy to cool till it is using the maximum energy it can without being able to do enough cooling.