I'll have a cold one, or in other words-Fridge

[MarkB]

Had my unit hooked to shore power with the fridge running, fan was unusually loud, so I turned it off then back on, it was quieter but still running, usually it doesn't run but maybe that is because it has been cooler previously. Anyway I was investigating, looking in the compartment from the outside, there is a panel screwed into the top of the compartment to hide the upper innards, so I took this off to see what was up there. One small fan btw. But what I discovered was the panel was blocking the airflow from the outside via the louvered door. So with the fridge now on the coldest setting in same conditions, no fan. We can call it a vanity panel, as the factory was probably trying to make it looked finished, you know, go that extra mile. So the point is, you might want to check your setup.

Yes, I'll have a cold one.

[Roger H]

I'm curious, Mark... what year and model is your coach, and which fridge do you have? Can you post photos?

I've heard of folks installing computer fans in the cooling unit compartment, and I recently saw a new Airstream Bambi with such an installation, but not having anything newer than an '06 Born Free (and '06 Bigfoot trailer) I've not seen any newer factory installations such as yours must be.

Thanks!

[MarkB]

It is a 2013 with Dometic RM 3762. There is one pitiful fan that blows on the cooling fins close to the top, it runs most all the time in this warmer weather so I think there is some improvement to be had. I have been reading about adding fans also, haven't decided on anything yet though. I don't think the design of the vent cover on the top of the roof adds anything either. LP doesn't seem to work as well as when it is operating off AC or DC, whichever it is.

[Roger H]

That's interesting... convection alone seems to work well and has in most of the coaches I've had, and those fridges always work better on propane than on electric. While I don't know how the newer models are constructed, I wonder if there's something blocking the vent path to the roof; insulation or something?

[bcope01]

My experience in all the travel trailers and motor homes that I have owned is that the fridge always ran colder on propane.

Bill

[MarkB]

I guess the fan comes on around 90-100 and it was that hot around here so maybe that was some of it. The LP did finally get cold but the unit was so hot and empty which might have been the problem. I still have to look into the fan situation and pull the cap off.

I did look at it closer, the vent is fine, no obstruction. I think the issue is because of the curvature of the shell the vent is inboard almost to the front of the fridge. The little fan probably is not real effective. To get to the fan mounting area the fridge will have to be slid out, there is no way to get to it from the top. Or mount a gang of fans in the roof vent.

[Roger H]

I think the issue is because of the curvature of the shell the vent is inboard almost to the front of the fridge. The little fan probably is not real effective.

You may already know this, but ammonia absorption refrigerators can take up to twelve hours to cool down to temp. And a good way to pre-cool them, if you need to, is to put cold 'stuff' in them... even if it's just a bag of ice, or a gallon milk jug filled with water and frozen

That really shouldn't be an issue... I had several Airstreams where the roof vent was significantly inboard of the burner because of the curve of the wall and roof, and they all vented and worked well.

Is there anything blocking the intake vent at the base of the fridge?

[bigdipper]

On occasion when parked with frig on sunny side and on propane I put a 6 inch fan with 2 D cells at bottom of refrig. on low setting. It actually moves quite a bit of air. Batteries last a long time.
Also leave outside vent door ajar.
All this is done only when it is hotter than anybody ought to be camping anyway. 95 and up.
Propane is better than AC in these circumstances if you are plugged in.
Dometic on the 2011 seems stronger than Norcold on 2001.
You can get a solar powered van but it seemed wimpy.
In these circumstances frig is always put on coldest setting with risk of freezing some contents over night.
Finally, being underway seems to result in more air flow through fins.
Just my opinion.
Ralph

[MarkB]

So the slide out of the fridge is pretty easy. Two screws at the top, two at the bottom, and two at the back. For some reason they used a square driver, maybe fridge theft is on the rise. And unhook all the wires and LP line. I used a cheap harbor freight 4 wheel dolley with an igloo cooler sitting on top, made the ride height to slide the fridge out onto and then able to roll it around.

The bracket that holds the 80mm fan is attached about a foot and a half below the cooler which is at the top. I detached the bracket and am going to move it up toward the cooling radiator and prob reuse the 80mm fan or maybe go to a larger 120mm and use two fans as there are cutouts for two, maybe use three fans, haven't decided. The present location of the fan is useless, why it ended up there is anybodies guess. I'll report back.

[MarkB]

Actually was a 92mm 2 pin fan on the back of the fridge.

I decided to mount 4 140mm fans in the top of the vent, using 1" angle aluminum along each side makes a nice tray and the fans fit right on. Also have a 4 fan controller to run the things. The fans are rated for 60+ cfm, I had all four running and was a little disappointed in the air movement, don't believe the one 92mm fan was much to brag about. Also one bad thing about this is if moisture gets to them though I didn't see any sign of it inside.

http://www.thetford.com/wp-content/uplo ... Manual.pdf

The above link shows why the baffle was installed at the bottom, at the top because of the rounded corner there is not a lot of clearance between the cooling coil.

Now have to figure out where to place the controller and wires. Figured if the fans don't work they are an easy replacement at the top, want to make sure the controller and wiring are accessible also. Horizontal fans are supposed to be ball bearing or the new maglev, vertical can use the hydraulic/rifle/sleeved bearing btw. Mine are hydraulic sleeved in the horizontal plane so I might pay the price. They are warrantied though, just send them back to Taiwan on your bill.

[Roger H]

Mark, have you figured out why you're not getting adequate convection through the system?

[MarkB]

I ended up putting two fans on the condenser fins at the top directly under the fins operated by the sensor and the four 140mm fans in the top of the vent operated by a separate switch located inside the compartment accessed from the outside. Using two circuits helps in the redundancy theory.

Turned on the fridge using LP without the vent cap installed and the empty fridge at the coldest setting about 5-6 hrs later is below freezing in the lower portion and the freezer is just below 0. The fans never turned on that I could tell and I was surprised at the amount of hot air coming out the top, so I believe the cap is the restriction. Installing vent fans via the solar setup I see on the net or using a better designed cap that I don't could be the answer to a better cooling fridge. In my case I have the option of using the fans at the top of the vent via the switch, and since I have a solar panel on top of the coach pulling 2 amps to run the fans I don't think would be a problem.

I was impressed with the fit of the fridge with the woodwork. Perfectly square and they didn't leave a lot of room around the sides, kind of wondered if the wood were to shrink if there would be problems! I also wondered if the polypropylene base that had channels routed into it are an industry standard or specific to Born Free. And inside the fridge compartment the finish was very well done even though it is not visible with the fridge installed. Don't think you would see that on lower priced coaches.

[Roger H]

using a better designed cap could be the answer to a better cooling fridge.

I'm a great believer in the KISS system. Installing a more efficient roof vent alone sounds like a significantly more elegant solution than trying to use a complex fan system to force air through an inefficient roof vent.

Google is our friend... and I see that there are several styles of roof vent available now. Since it appears that your vent is the restriction in your system, could you post a photo of it so other folks who may have similar problems know what to look for?

[MarkB]

Google is only your friend when you get what you want.

I think the outer door was also a restriction. At a steady 32 overnight I closed the outer access door and early morning the fridge temp had raised a degree and the condenser fans were running, so I opened the door and turned on the top vent fans and the fridge returned to 32 and the condenser fans turned off and stayed that way when I turned the top vent fans off. I used different configurations of the setup to see what was going on, the access door has louvers but the louvers don't have very much "lou" to them, so a couple of needle nose pliers and twist opens it up quite a bit.

Now on lectric the fridge empty is at 32:) without fans with ambient temp of around 80 in still air. So maybe all along it was the access door not allowing air movement, but with the improved fan situation I can cross the desert in style, eating ice cream.

This is without the baffle at the bottom btw, combination of restrictive access door and baffle might have been the problem.

And if BF is reading this, please don't use the sandpaper traction pieces on the bumper and top of ladder, tracking sand on top of the coach is nasty business. And removing the sandpaper is nastier! Thank you.

[bigdipper]

I too believe cracking outer door increases convection flow but have found this necessary only in 90+ parked on sunny side.
Ralph