Improved Cooling for Norcold

I was reading the installation manual for the Norcold and it stated that the rear baffle should come right to the bottom of the cooling fins. I noted my baffle overlapped the fins by about 1 inch. 100+ degrees was causing the Norcold to go to temperatures above 40 degrees. I first installed a computer case fan (110 volt, .25 amp) to "push" air up and out. It did not make a difference. I then took tin snips and cut the baffle so it was level with the fins and removed the fan just to see what would happen...perfect, it fixed the problem. Below is a picture. The cut is not pretty, but effective.



I may get the fan running again just to see what will happen.

would you mind make this explanation (of exactly what you cut with tinsnips) a little bit "clearer?" I've looked at this picture a few times and can't make 'heads of tails' of it. What did you cut? Where?

Thanks!

Here's a Norcold drawing showing a side view of how the baffle should be positioned.

icechex said:

would you mind make this explanation (of exactly what you cut with tinsnips) a little bit "clearer?" I've looked at this picture a few times and can't make 'heads of tails' of it. What did you cut? Where?

Thanks!

Click to expand...

Here are a couple of pics of my baffle installation for my Dometic.
They, at least one, should clear thing up a bit.
The tin snips are just used to cut the sheet metal to size.

Peace
Dave

You know, after fighting and winning the improperly installed RV refrigerator in a slide, I wonder why the refrigerator makers just don't put a piece of sheet metal spaced 1/4 inch back of the cooling fins covering the entire back of the refrig to channel "venting" airflow over the fins????

wdk450 said:

You know, after fighting and winning the improperly installed RV refrigerator in a slide, I wonder why the refrigerator makers just don't put a piece of sheet metal spaced 1/4 inch back of the cooling fins covering the entire back of the refrig to channel "venting" airflow over the fins????

Click to expand...

Bill,

I think if the frig is not in a slide, the vent can be straight up through the roof and cooling is simpler because the heat just rises straight up and out. They probably don't need a baffle for that type of installation.

Dave - thanks for the pictures. The difference must be that mine is a Norcold and yours a Dometic. After looking at your pics and looking at my fridge - I'm still in the dark. I'm a retired Refrigeration/Air Conditioning Mechanic - my father was a Design Engineer (Electrical) ... he could see pictures in his head - "I can't."

I still do not have a "clear idea" as to what is going on here. I need to 'know' what I'm trying to do, then, I can "rig, fix, or engineer" anything ... but untill I know what it is I'm trying to do ...it's just mud.

THANKS ANYWAY!

Dan - thank you for the drawing. After looking at the drawing and looking at my fridge - I'm still in the dark. I'm a retired Refrigeration/Air Conditioning Mechanic - my father was a Design Engineer (Electrical) ... he could see pictures in his head - "I can't."

I still do not have a "clear idea" as to what is going on here. I need to 'know' what I'm trying to do, then, I can "rig, fix, or engineer" anything ... but untill I know what it is I'm trying to do ...it's just mud.

THANKS ANYWAY!

UPDATE! I finally grasped (in my muddy mind) this whole thing. Bottom line - my baffle is perfectly cut and evidently is not my problem - which btw - is when the ambient temp gets around 90 degrees the temp inside the fridge gets up around 45 or 50.

So far I've been able to solve this problem by "fans" but for the last couple of days that has not helped. Note: I moved the 5th wheel 2 days ago and as we all know - "moving the RV "changes" things" ..lol.

I suspect a 'gremlin' and will not be surprised when I arrive in Oklahoma (after 3 days of travel) to find that the fridge is working ok again (albeit with the use of my fans).

My "BIG" problem is that I don't trust this POS - which is prolly cause I'm not accustomed to it's basic design (electrical, mechanical, gas, whatever) ... it's a foreign animal to me (give me freon, electric, and a compressor and I'll make it work one way or the other, lol)

At the moment I'm wavering between jerking out this thing and replacing it with a "normal/residential" refrigerator or trying to live with it.

The problem with "living with it" is I bought this new 5th wheel (2012 Big Country) to not have to worry about stuff like this , but then again ... it's a 5th wheel (why am I surprised?).

Thanks again for all the suggestions and pictures/diagrams - it was appreciated.

BTW, isn't there a "step by step" manual/directions on here (somewhere) on how to replace a fridge with a residential refrigerator?

Anyone having a link to this I would appreciate it.

Thanks again!

Hi icechex,

There can be various causes of cooling problems. Although you have a Norcold, our Dometic RM1350 Troubleshooting Flowchart may be helpful to you.

As for replacing it with a residential refrigerator, here's a link to a thread describing just that.

thanks for the links!

danemayer said:

Bill,

I think if the frig is not in a slide, the vent can be straight up through the roof and cooling is simpler because the heat just rises straight up and out. They probably don't need a baffle for that type of installation.

Click to expand...

Dan:
The magic idea for good outside heat exchange venting is that AS LITTLE AS POSSIBLE of the rising vent air in the refrigerator compartment should bypass travelling across the heat exchange fins on the back of the refrigerator. Any spacing away from the rear wall, either in a slide or a "conventional" RV refrigerator compartment will allow rising venting heat exchange air to bypass the cooling exchange fins. Therefore, my idea of a rear sheet metal panel to contain the rising air on the back of the refrigerator. A very good old website on RV refrigerators (that is no longer up due to the owner's retirement) recommends 0 to 1/2 inch clearance between the back fins of the RV refrigerator and the back wall of the compartment, with the dead spaces at the sides and top of the refrigerator filled with insulation batting. This is what I did to my unit 5 years ago, along with an airflow directing baffle at the top outside vent, and it has worked terrific in all sorts of weather since then.

Another idea is if you use a fan use it to exhaust the hot air out of the compartment at the top. This is the most effective method to remove heat from a box.

Then make sure you have as much airflow over the cooling surfaces. It would be best if the cooling surfaces were in an efficient duct that maximized flow over the cooling fins.

Cooling and heating surfaces should be as flat black as is possible and as conductive as possible. That is why so many heat exchangers use stove flat black paint. The blackest surfaces exchange heat most efficiently. White and reflective surfaces least efficiently.

Another optimization would be to make the outer cover and surround not only white, but as silvery shiny as possible to keep the heat out This could be tested with Aluminum foil. Don't block the air flow. Flat black stove paint would be the worst case for the outside cover. If you have a dark full body paint, you could try to line the inside of the outer wall with some additional silver metallic material that is not flammable. Again, don't block the air flow.

wdk450 said:

Dan:
The magic idea for good outside heat exchange venting is that AS LITTLE AS POSSIBLE of the rising vent air in the refrigerator compartment should bypass travelling across the heat exchange fins on the back of the refrigerator. Any spacing away from the rear wall, either in a slide or a "conventional" RV refrigerator compartment will allow rising venting heat exchange air to bypass the cooling exchange fins. Therefore, my idea of a rear sheet metal panel to contain the rising air on the back of the refrigerator. A very good old website on RV refrigerators (that is no longer up due to the owner's retirement) recommends 0 to 1/2 inch clearance between the back fins of the RV refrigerator and the back wall of the compartment, with the dead spaces at the sides and top of the refrigerator filled with insulation batting. This is what I did to my unit 5 years ago, along with an airflow directing baffle at the top outside vent, and it has worked terrific in all sorts of weather since then.

Click to expand...

Bill

I was wondering if you had pictures of what you did to your refrig? If so.... maybe you could post them. I'm at a loss trying to picture 'things' in my head (my dad was an engineer but my brother got that trait not me, lol). Sounds to me that - "that is the problem with my refrig" (improper air flow).

In fact the sheet metal backing (baffle) on my fridge is cut at an angle and only about 30% (of it) is at the bottom of the fins (the rest of it - is an inch or more "below" the fins). I can easily 'see' that most of the air is bypassing the coil instead of flowing over it. I am at a loss how to bring the baffle up to the fins (attaching it to what - 'air') The proper fix looks to be a whole new baffle which may be what I end up doing - although - I am so sick of this thing (fridge) that if I do anything extensive (even pulling it out from the wall to fix the baffle problem) I will probably just continue "pulling/pushing" it "right out the door" and go buy a residential unit.

Any help/suggestions/pictures would be appreciated.

I have attached a primitive drawing, but it should explain how the baffle will work.

Peace
Dave

UPDATE: We moved our 5th wheel (135 miles). Weather about the same in both places (no dramatic differences).

Guess what?

Refrigerator started to work correctly. Temp inside Refrig while traveling (and on auto/propane) dropped to 22 degrees (was holding 40 degrees even with fans) when we arrived. Wow! Freezer Temp dropped to 16 degrees (was holding at 20 degrees). Wow!

This morning - inside of box holding at 25 degrees(nothing freezing inside refer) and Freezer "down" to 10 degrees. Hmm... these temps seem to be pretty normal. The refer is working!

Conclusion 1: it's all in the "liquid" that is in the refer combined with the moving/jostling it takes when the 5th wheel is going down the highway.

Conclusion 2: fans, coils, baffles, etc etc etc - doesn't (in my case) seem to make any DIFFERENCE at all and by merely moving the RV I've fixed the problem.

Conclusion 3: the problem will return on a future move or it won't. I would bet that it "will return" as a result of a move and that I will have to live with this problem as long as I depend on this refer.

Conclusion 4: since I have no desire to spend $1200 (plus tax) for a refer and then expend the labor to install it correctly (with all the modifications needed to insure that it will work properly "and" look nice in our rig) as long as I already have one working I'm suspending my decision to replace with residential unit, admitting that I will have to live with this 'gremlin' for the time being.

THANKS DAVE for the drawing - it helped me to further envision what the baffle needs to do. However, based on what has now happened in this refer experience - I am 'convinced' that this refer is so designed/installed to work "IF" the liquid in it is not "bounced around" to the point that something 'clogs up' inside to prevent it from working properly.

and that all I have to do to "Fix" the problem is move the 5th wheel.

Gee....ain't I lucky?

"primitive" is what I needed I think (LoL) Many thanks - it helped to clear things up for me although I'm not sure how much it will help me with "my" problem. Read my latest reply for more.

again, thanks!

When the gremlin strikes, if cooling is equally poor on either propane mode, or 110V AC mode, and you're sure you don't have air leaks or internal air circulation issues, there may be a partial blockage in the cooling system. Most of the time it circulates ok and the frig cools ok, but sometimes it gets stuck, reducing normal flow of fluid through the cooling unit.

Sounds like that's what's happening and towing breaks it free.

Could also be a problem with the thermistor or its connections being intermittent.

If your problem is on 110V operation and you haven't switched to propane mode to see if it works better, it could be a problem with the heating coil having intermittent problems. If you haven't tried switching to propane mode, next time there's a problem, you should try that.

danemayer said:

When the gremlin strikes, if cooling is equally poor on either propane mode, or 110V AC mode, and you're sure you don't have air leaks or internal air circulation issues, there may be a partial blockage in the cooling system. Most of the time it circulates ok and the frig cools ok, but sometimes it gets stuck, reducing normal flow of fluid through the cooling unit.

Sounds like that's what's happening and towing breaks it free.

Could also be a problem with the thermistor or its connections being intermittent.

If your problem is on 110V operation and you haven't switched to propane mode to see if it works better, it could be a problem with the heating coil having intermittent problems. If you haven't tried switching to propane mode, next time there's a problem, you should try that.

Click to expand...

Yeah I think my problem is "moving the 5th wheel," and though it may never happen again I must be prepared for it to strike after "any move." Appreciate your suggestions. Thanks! Oh yeah - I have tried it on propane with the same results which reinforces my idea that my problem is a 'gremlin' in the liquid and which I'm pretty sure there is no 'fix.'

icechex said:

Bill

I was wondering if you had pictures of what you did to your refrig? If so.... maybe you could post them. I'm at a loss trying to picture 'things' in my head (my dad was an engineer but my brother got that trait not me, lol). Sounds to me that - "that is the problem with my refrig" (improper air flow).

In fact the sheet metal backing (baffle) on my fridge is cut at an angle and only about 30% (of it) is at the bottom of the fins (the rest of it - is an inch or more "below" the fins). I can easily 'see' that most of the air is bypassing the coil instead of flowing over it. I am at a loss how to bring the baffle up to the fins (attaching it to what - 'air') The proper fix looks to be a whole new baffle which may be what I end up doing - although - I am so sick of this thing (fridge) that if I do anything extensive (even pulling it out from the wall to fix the baffle problem) I will probably just continue "pulling/pushing" it "right out the door" and go buy a residential unit.

Any help/suggestions/pictures would be appreciated.

Click to expand...

Here is a link to a .pdf drawing of my baffle from an old thread, modified and cleaned up by another forum member:
https://drive.google.com/file/d/0Bw3atuhfb0GMMzVRclZhRmNiMHc/view?usp=sharing