Fridge Performance Survey

[Joe Romas]

Zach0

OK I HAVE done it on my 17' Casita.

Looking at the picture of your lower vent I can tell it's WAY TALLER then what's on my Casita. My lower opening is only 13" high and starts at the very bottom, looks about half as high as yours.

That extra space of your opening is where the lower air deflector goes.

So maybe if you mounted a piece of Aluminum angled inward on the top maybe even touching those coils and outward on the bottom to the outer vent frame bring it down from whatever your opening measures to 13-14 inches opening. 14" is where my lower baffle starts.

the space that you would be covering has nothing that requires you getting to it. just about the top of the round tank.

Your burner section also has what looks like an air intake that Casita does not have.

A vertical baffle separating the heat from the burner section on the right from the cooler or less hot air from the zig zag tubes and fines at the top.

UPDATE: I just noticed your refrigerator's tubing is not rusted, there was a lot of rust on my 1999's tubing, that's why I replaced it so maybe it was replaced and that might be why the burner is off (not quite the same mounting??)The piece the burner is mounted to is screwed to the boiler tube with a screw. Thinking back from when mine was apart other then making sure the tube the flame sits on I properly sitting in the bracket there's not much you can do there.
It looks like the burner tube is properly seated in the bracket in your picture but I had trouble getting mine seated right but even so it would have been the opposite of yours so ?????

I found early on the lower coils need vented well too and are often overlooked and yours are just open.

I think I mentioned already that Dometic says to preform testing on the refrigeration system by hooking 120 volts directly to the 120 volt heater. as that just about eliminates everything. I tested mine and it used 165 watts, that's a lot of heat.

I know this is a couple of steps back but maybe it's time to start at ground ) again.

Joe

[ZachO]

Thanks guys.

So possibly somehow attaching a baffle to the inside of the lower vent, or like in Civilguys diagram, having one extend down from above the vent, is another thing to try? And you think actually blocking off some of the vent with a baffle will help?

It's true, it's a huge lower vent giving me access to stuff I don't need access to. Wonder what the reasoning was on that...

The fridge does seem to work better on AC, and I'm sure it's because it produces less heat.

I ran it on propane for the first half of today, and it did warm up a bit. And the flame is still off-center. I worked on it a little and got it more centered, but still not enough. But the fact that I could move it a bit is encouraging.

I guess I should still work on a vertical baffle. And if I take the cap off the flue, find some tubing at NAPA or wherever, and cut a hole in it so the wire that the baffle inside the flue hangs on can still stick out, maybe I can actually extend the flue up to the top vent.

We'll see. I'm not sure I'm going to ever get good cooling once the temps hit 90, but I did notice over the last few days on AC that so long as temps drop into the 50s overnight and I'm very careful with opening the door (along with some supplemental cold from ice packs I'm freezing in the house), the fridge just barely stays cold enough. It's actually been at 30 degrees the last couple mornings, but always manages to get back up over 40 by the end of the day.

We'll see!

Thanks a lot for the help.

I have had a few carbureted vehicles and have heard of carb icing but never experienced it. I actually have an old 75 Honda motorcycle but it hasn't been running lately...

[Civilguy]

Originally Posted by ZachO

Thanks guys.

So possibly somehow attaching a baffle to the inside of the lower vent, or like in Civilguys diagram, having one extend down from above the vent, is another thing to try? And you think actually blocking off some of the vent with a baffle will help?

It's true, it's a huge lower vent giving me access to stuff I don't need access to. Wonder what the reasoning was on that...

Zach,

I think you are all over it, but I want to make sure I didn't mess this up. My thought here is to reroute the air from the lower vent but not to block any of it. I was trying to show in my crummy sketch that the air is still flowing in through the top half of the lower vent.

The whole exercise here is to get as much air as possible flowing through the fins and tubes. When the air moves by at a distance, it's just not removing heat as effectively. I know this because JD and Joe Romas and Clif have shown us that it works!

Also, I gave some thought to your mention in post #89 a few days back about the preferred direction of flow for fans. Bottom line, for these refrigerators with sidewall venting, having the fan at the top as you mentioned is probably going to be the most effective. However, fans use battery power so I am focused on getting the airflow optimized so that fans won't be necessary under most conditions. Might as well go for the gold, right?

[Joe & Cherie]

Please ignore this post if its already covered or ruled out - I just couldn't read thru it all to find out.....lol.

When I had my Casita with a 3-way, I ended up one spring with warm temps on LP, but nice and cold on 110v. The problem was the LP regulator between the tanks. It was older and not putting out the pressure required. Sure I got a flame that "looked right" but it wasn't doing the job. Replaced the regulator and temps got back down into the 30's on hot days on LP.

Just a thought

[ZachO]

Thanks Mike, that makes sense. Just kind of a "dangling" baffle? Your diagram does show that well, it was just late when I looked at it last night. Yeah, if I can get it to work well without the fan, that'd be great. I don't have high hopes for that, but who knows!

Joe, yeah, this thread is long. Regulators have come up. Mine is only a year old, but at some point I do want to test the pressure at the fridge.

[Civilguy]

Originally Posted by JWScarab

Please ignore this post if its already covered or ruled out - I just couldn't read thru it all to find out.....lol.

Heck Joe, I pretty much ignore anything you post anyways!

Yeah, I have been dragging Zach through a lot of the "theory" that I shared with you by emails. The difference is, we've got some people on this thread that have actually done it and made it work.

So, I'm learnin' and 'splainin' all at the same time...

[ZachO]

I remember seeing them somewhere...but could someone post a photo of the vertical baffle to separate the flue from the coils? Every time I've gone back to find it, I don't see it, and I can't view the Casita Forum stuff since I'm not a member.

Thanks!

When this is all over, if I have good results, I'll condense this all down into an instructional thread with easy-to-find advice and mods.

Last time I had the top vent off I also took a string and tied those two water lines up against the inside of the shell, under the fan, so they aren't sitting right there on top of the fins.

I know the angle on the photos is hard, but the confusing ones are taken from the top vent, looking down, kind of sitting just under the fan (you can see it as a black blur in the top of the photo), looking one way down the baffle, then the other way. This is the baffle right under the fins.

[Joe Romas]

Zach0.
The following is from the thread on the Casita club. It started 2 years ago with a refrigerator that just would not work in a Casita and was removed. It worked perfectly in a hot service facility and has since found a new home and is preforming well. Larry does modification and repairs on Casita trailers. Maybe the following will give you some insite as to what your up against.

Joe

I just went back and read that original post that started this thread just about two years ago this week. We are so pleased that our friends here took this info and turned it into a solution. At least a solution for most.

For what it's worth, the following spring we installed that take out fridge in a friends Casita and last we heard it's still performing well. I don't think we did anything special when we installed it and I don't remember if he did any mods larter or not. Perhaps hill join in and update us.

But what this proves is that there are solutions for most but it also proves that no two installations are alike. This totally non performing fridge installed in a different trailer has performed well. So...one can conclude that you might have to try several of the mods defined in this quite lengthy thread to find the one that works in your situation.

Larry

[ZachO]

Huh! Interesting. Discouraging and encouraging at the same time.

I got motivated and worked on centering the flame. And...well I learned something but don't understand it well enough to help me yet. I also did something that certainly will not help me.

I lit the flame, and more consciously noticed something I've only sort of noticed before, which is that yeah, my burner is slightly off center, but also the flame is being pulled even farther off center. Like there's a draft pulling it sideways.

I know that when I last pulled the fridge and cleaned the chimney, I put the flue baffle back in and didn't quite remember how it was oriented before. And there's nothing in the diagrams I've seen anywhere that tell me how exactly it and the cap that sits over it and the flue are supposed to be oriented. But there aren't really many options, so it didn't seem to matter much.

Either way I wondered if maybe the way it was sitting was causing sort of a "crooked" draft. I don't know

I pulled the cap and baffle, and the flame was way more centered. Not perfect but the glowing edge of the bottom of the flue stopped glowing. So something is going on there.

But...clearly the fridge needs to be out to pull the flue baffle. Because I totally distorted the baffle pulling it out, and burned myself. I bent it back into shape enough to be able to stuff it back down the flue, but I'm guessing it needs to be replaced. And I'm not finding a replacement so far...

But as soon as it's back in, no matter which way I spin it, the flame is off-center in the same direction, heating the bottom of the flue.

I dunno. Thankfully I can plug in right now and use AC.

[The Minimalist]

Your flue baffle really just hangs there on a wire hook On mine there are two slots 180 degrees apart that you hang the the baffle on and either one will work. The only way anything will change is if someone has replaced the wire hook and made it too long or short. Nevertheless, I don't think that would pull the flame off center.

Is it possible that burning off center for a while has burned a hole in the bottom boiler cover? I don't think that would cause the flame to draft off center either, as the boiler case is packed with insulation, unless that has been damaged as well.

Since you have found that you can get the flame centered better, do you see any way the burner could be moved vertically into the flue? I know on mine the flame is actually halfway up in the flue.

Keep plugging. You'll get there.

[ZachO]

Yeah I read that all the baffle does is cause the heat to spiral as is rises up the flue. So any corkscrew shape in the flue, at the right depth, should be fine? So maybe the fact that I mangled it doesn't matter..?

Mine is on a wire hook, but it isn't clear how to hang it. I have the flue cap, which has a hole in it, but when I've tried to put the hanger through that hole, it seems pretty clear that it isn't supposed to go there. So mine has just been hanging on the upper rim of the flue, then the cap goes over the top.

It looks to me like the flame has only been off-center for a few months. Probably something I did at some point earlier this spring messed it up; probably when I had the fridge out last. Maybe with the baffle when I cleaned the flue? I don't know. I don't think there's a hole anywhere but I guess I don't know. Obviously the baffle needs to be there but I was tempted to leave it out, since the flame was so much better.

My flame also extends up into the chimney a ways. So the fact that it's off-center worries me, since because it extends that far up, being off-center means it's hitting the side of the flue pretty hard. It seems pretty unsafe to me.

I may need to get an expert to look at it. Dometic never responded to the email I sent with photos. A couple more paychecks and I guess paying someone will make sense. For now it seems like I can keep plugging in for a while. Just don't feel safe taking it out camping.

[Civilguy]

Zach,

If you think your flame is not be correct, it might be time to build a water manometer and check the pressure. One of the earlier posted links on here lead to another thread where someone had done it. Joe Romas' post #32 also has a good link. There's also the tiny orifice to be carefully cleaned...

7.2 Orifice
The Dometic orifice is a brass alloy with a man-made ruby
pressed in the center that has been laser-beam drilled in
a spiral pattern. The orifice is cleaned by using an alcohol
based solvent. Soak the orifice for approximately 1 hour
and allow to air dry. Don’t insert anything in the center of
the orfice it will harm the man-made ruby. Don’t use an
air nozzle to blow thru the orifice as the ruby could be
moved. Never over or under size the orifice on a Dometic
refrigerator. The cooling unit is designed to work with a
predetermined amount of heat and modifying the orifice
size will decrease cooling. If there is a lack of cooling on
gas operation, verify the orifice is the proper size per the
chart .

The spiral baffle is a turbolator. It is there to prevent the heat from moving straight up the flue and to help get it to the ammonia. It's the same thing you'll find inside a gas water heater's flue.

[Borrego Dave]

Now that's one funny video clip

[ZachO]

I really thought he was serious there until the end... I still can't figure out whether any of it is made up, or he just purposely uses the most complicated language possible to describe an actual thing...

I don't know.

I'll get there, but I'm annoyed that at this point I don't even feel safe running it on gas.

I mean, how does a flame suddenly get off center? It's all bolted together with no room for adjustment without bending or cutting metal. So what changed? If it had been burning off center like that since I bought it, a) I would have noticed and b) it would be way more charred.

Something happened either late last fall or early this spring. I had the fridge out this spring. But I didn't do anything out of the ordinary, other than running a shotgun cleaning wire brush through the flue.

Just frustrating that I went from a inadequately cooling fridge to an unsafe one that I can't run on gas, meaning when I actually camp, I don't have a fridge.

Arrgg!!

Once I track down a new baffle (if I even can), I'll just pull the fridge again and look at everything really close, or even drop it off with a technician.

Oh, and I've definitely cleaned the orifice. The flame is blue and clean and strong, just off-center. Now whether the pressure is correct I won't know till I do that test, but the burner and orifice and flame color and flame height all check out.

[The Minimalist]

Zach:

I thought you had given the make and model of refrigerator you have, but I have searched high and low in this thread and can't find it. Could you give us that information?

Thanks.

[Civilguy]

(I deleted the video from post #132 and am reposting it here separately as it is indeed complete and total baloney.)

Your turbolator is not to be confused with the turbo encabulator in this old gem by Bud Haggart:

• In c. 1977 Bud Haggart, an actor who appeared in many industrial training films in and around Detroit, performed in the first film realization of the description and operation of the "Turboencabulator", using a truncated script adapted from Quick's article. Bud convinced director Dave Rondot and the film crew to stay after the filming of an actual GMC Trucks project training film to realize the Turboencabulator spot.[7]

https://www.youtube.com/watch?v=5hMAaOdNkgI

[ZachO]

Dometic RM 2301

What I notice is that all the openings on the burner seem fine, except the very last one, farthest away from the orifice. The flame from it angles outward. The entire assembly is slightly off center, but it seems like if that one slit in the burner weren't being somehow pushed or pulled outward, I wouldn't have a problem.

Well, no problem other than my fridge not cooling.

[ZachO]

See how the last two, but especially the very last flame is being pushed/pulled so far over?? Weird.

[redbarron55]

The draft around the end of the boiler is pulling the flame and the heat has the metal on the right side glowing.
Move the burner left

[ZachO]

If only it were that easy! Please tell me if it is.

There is no built-in adjustment for centering the burner that I'm aware of. I've tried bending the metal, prying on different things, looking all over for something I can adjust. I might have moved it a centimeter. All I can see happening with more of that is me breaking something.

To actually move the flame to where it needs to be I see my options being:

to actually remove the burner element and cut a little less than 1/4" off it, then re-flare the end and reinstall.

Somehow move the entire bracket over about the same amount.

But the bracket is not one piece, nor does it have any room for adjustment. It's held in by multiple pieces of metal which are part of larger parts of the fridge body, attached by sheet metal screws. I'd need to pull the fridge, take multiple pieces of sheet metal off, drill new screw holes and try to put it all back together, lined up correctly.

Does that seem like the right way to make a minor adjustment?

Honestly, please tell me if I'm missing something, but I see no "correct" way to adjust where the burner is centered. It's built how it's built, without any thought of a need for adjustment.

What I'm seeing is that the burner has always been lined up the way it is now. Not 100% perfectly centered, but close enough. I can't see any way for it to move "out of adjustment". Sometime recently, something happened that effected where the actual flame is being pulled once it comes out of the burner.

I tried turning off my exhaust fan but that had no effect.

If you sense any frustration in my post it's not at your advice and I'm not being dismissive, I'm just frustrated at the situation. I could very well be missing something very obvious so if you know something I don't, let me know!

Without writing an entire novel trying to explain it, I'll just say that my best option so far has been to bend the bracket which holds the burner. But by bending to get the burner to move left, it also moves sideways. Can't make it move one way without it also moving the other.