unlevel refrigerator question

[rider1520]

I had to camp at a few spots that I could not get even close to level, the refrigerator seemed to work fine but does using it when it is completely "outside the bubble" have a cumulative affect?

[69_Avion]

Carl n Susan wrote:
I wouldn't be overly concerned about being level. Newer Dometic (and Norcold) refers operate at up to 3 degrees off level side-to-side and 6 degrees off level front-to-back (http://dutchmen.com/image/data/documents/parts/Norcold_1200_Series_Refer_Manual.pdf Page 18). If you are comfortable walking about inside, the refer will be fine.

Question:
A RV which is off-level by 3° degrees is how many inches side to side?

Answer:
1 degree = Pi/180 radians, so 3 degrees = Pi/60 radians. The width of the RV is typically 8’. Therefore the arc length (the curved distance traveled (close enough for our work)) is radius times the angle as measured in radians. So arc length = 8(Pi/60) feet and Pi is roughly 3.1416

Solving the formula gives:
8(3.1416/60) = 8(0.05236) = 0.4188’ = 5.02656"

I suspect most of us would be very uncomfortable if one side of the RV was 5" lower (or higher) than the other.

Great explanation. There is no doubt that the more "level" the refrigerator is the better, but this gives folks, like the OP, an idea of how much a degree off level actually is.

Thanks,

[rider1520]

thanks everyone for the VERY detailed explanation.I typically am able to stay at least half in the bubble, but this last time was almost completely outside and I was out of leveling blocks. It was only for a two day weekend but still replacing most anything in an RV is expensive so I certainly try to use the equipment with that in mind. Thanks for all the feedback

[Carl_n_Susan]

I choose 3 degrees as an example because:

1. The resultant 5+ inches over 8' is obviously an excessive amount of slope.
2. Not all refers are mounted longitudinally. The rear kitchen models typical have the refer mounted transversely.

You will not be comfortable in a RV which is 3 degrees off level, much less 6 degrees.

[Bobbo]

Carl n Susan wrote:
I wouldn't be overly concerned about being level. Newer Dometic (and Norcold) refers operate at up to 3 degrees off level side-to-side and 6 degrees off level front-to-back (http://dutchmen.com/image/data/documents/parts/Norcold_1200_Series_Refer_Manual.pdf Page 18). If you are comfortable walking about inside, the refer will be fine.

Question:
A RV which is off-level by 3° degrees is how many inches side to side?

Answer:
1 degree = Pi/180 radians, so 3 degrees = Pi/60 radians. The width of the RV is typically 8’. Therefore the arc length (the curved distance traveled (close enough for our work)) is radius times the angle as measured in radians. So arc length = 8(Pi/60) feet and Pi is roughly 3.1416

Solving the formula gives:
8(3.1416/60) = 8(0.05236) = 0.4188’ = 5.02656"

I suspect most of us would be very uncomfortable if one side of the RV was 5" lower (or higher) than the other.

Actually, it is worse than that. The fridge needs to be less than 6 degrees front to back. Since the fridge front to back is side to side in the RV, you need to use 6 degrees or Pi/30 radians. So it is
8(3.1416/30)=8(0.10472) = 0.8377'=10.05 inches.

Side to side for the fridge is front to back of the RV and is 3 degrees, when applied to a 32 foot rig with a 220 inch wheelbase gives 11.5 inches.

If you can walk, the fridge is OK.

That being said, I keep it within 1/2 bubble.

On edit:

An easy way to figure the numbers for your rig is the TAN(angle in degrees)*length(in inches). The TAN(3 degrees) is 0.05241 and the TAN(6 degrees) is 0.1051.

So, use the width of your rig in inches multiplied by 0.1051.

Use the wheelbase of your rig in inches multiplied by 0.05241.

[CloudDriver]

Carl n Susan wrote:
I wouldn't be overly concerned about being level. Newer Dometic (and Norcold) refers operate at up to 3 degrees off level side-to-side and 6 degrees off level front-to-back (http://dutchmen.com/image/data/documents/parts/Norcold_1200_Series_Refer_Manual.pdf Page 18). If you are comfortable walking about inside, the refer will be fine.

Question:
A RV which is off-level by 3° degrees is how many inches side to side?

Answer:
1 degree = Pi/180 radians, so 3 degrees = Pi/60 radians. The width of the RV is typically 8’. Therefore the arc length (the curved distance traveled (close enough for our work)) is radius times the angle as measured in radians. So arc length = 8(Pi/60) feet and Pi is roughly 3.1416

Solving the formula gives:
8(3.1416/60) = 8(0.05236) = 0.4188’ = 5.02656"

I suspect most of us would be very uncomfortable if one side of the RV was 5" lower (or higher) than the other.

I believe that most RVs have refrigerators installed so that the front to back of the fridge faces across the 8 ft width of the RV. The side to side dimension of the fridge is related to the front to back of the RV. This means that Norcold's allowable 6 degree out of level front to back of the fridge is more like a 10 inch side to side tilt for the RV. For the 158 inch wheelbase of our Minnie, the allowable 3 degree off level for the fridge corresponds to an 8 inch off level front to back tilt of the RV.

That said, we try to keep our Hoppy levels in both directions within 2 inches of dead level. We never go over 3 inches out of level with the fridge running.

[Gdetrailer]

Carl n Susan wrote:
I wouldn't be overly concerned about being level. Newer Dometic (and Norcold) refers operate at up to 3 degrees off level side-to-side and 6 degrees off level front-to-back (http://dutchmen.com/image/data/documents/parts/Norcold_1200_Series_Refer_Manual.pdf Page 18). If you are comfortable walking about inside, the refer will be fine.

Question:
A RV which is off-level by 3° degrees is how many inches side to side?

Answer:
1 degree = Pi/180 radians, so 3 degrees = Pi/60 radians. The width of the RV is typically 8’. Therefore the arc length (the curved distance traveled (close enough for our work)) is radius times the angle as measured in radians. So arc length = 8(Pi/60) feet and Pi is roughly 3.1416

Solving the formula gives:
8(3.1416/60) = 8(0.05236) = 0.4188’ = 5.02656"

I suspect most of us would be very uncomfortable if one side of the RV was 5" lower (or higher) than the other.

Perhaps YOU wouldn't mind "experimenting" on your OWN fridge at 1,2 or 3 degrees off level for a while?

The perhaps report back on the results..

Or perhaps you are willing to bump the OP and anyone else the money to repair or replace their fridge by following your advice based on MANUFACTURERS REVISED specs?

You see, the manufacturers have a VESTED "interest" in SELLING NEW fridges. If you do your best to operate the fridge fully within LEVEL they will not "sell" as many replacements..

The fact is now days these fridges do not seem to last as long as the ones made 20 or even 30 yrs ago.. I wonder why? Perhaps because folks "like" the fact that the manufactures specs have been lowered to the point that anything goes?

The truth of the matter is the manufacturers CAN NOT ALTER, BEND OR CHANGE GRAVITY. Gravity is the MAIN PRINCIPLE to how the fridge works. The fridge WORKS BEST AT LEVEL and the further off level you go the less it works..

Its YOUR money to do what you want to, myself I don't like throwing it away...

[ScottG]

I'd be very concerned about running off level. Some do it regularly only to find it won't cool on the odd hot day.
There's nothing you can do now but be more careful with it next time. After 24 years of RVing I've never "had" to operate that far off level.

[Carl_n_Susan]

I wouldn't be overly concerned about being level. Newer Dometic (and Norcold) refers operate at up to 3 degrees off level side-to-side and 6 degrees off level front-to-back (http://dutchmen.com/image/data/documents/parts/Norcold_1200_Series_Refer_Manual.pdf Page 18). If you are comfortable walking about inside, the refer will be fine.

Question:
A RV which is off-level by 3° degrees is how many inches side to side?

Answer:
1 degree = Pi/180 radians, so 3 degrees = Pi/60 radians. The width of the RV is typically 8’. Therefore the arc length (the curved distance traveled (close enough for our work)) is radius times the angle as measured in radians. So arc length = 8(Pi/60) feet and Pi is roughly 3.1416

Solving the formula gives:
8(3.1416/60) = 8(0.05236) = 0.4188’ = 5.02656"

I suspect most of us would be very uncomfortable if one side of the RV was 5" lower (or higher) than the other.

[ktmrfs]

another bit of info from dometic is that if the trailer is level enough for you to be comfortable sitting, sleeping, walking in the trailer, it's level enough for the fridge.

What I've noticed is that a trailer doesn't have to be very far off level before it's noticeable when you sit down or especially lay down.

And IIRC front/back vs. side/side leveling sensitivity in fridges is different. I think, but hopefully someone else has the info that side/side level of the fridge is more important than front/back level of the fridge.

[Old-Biscuit]

Yes 'off level' operation will cause plugging and the damage is accumulative.

The following is from Dometic Refrigerator Manual

"IMPORTANCE OF LEVELING A
REFRIGERATOR
In an absorption refrigerator system, ammonia is liquefied in the finned condenser coil at the top rear of the refrigerator. The liquid ammonia then flows into the evaporator (inside the freezer section) and is exposed to a circulating flow of hydrogen gas, which causes the ammonia to evaporate, creating a cold condition in the freezer.
The tubing in the evaporator section is specifically sloped to provide a continuous movement of liquid ammonia, flowing downward by gravity through this section.

If the refrigerator is operated when it is not level and the vehicle is not moving, liquid ammonia will accumulate in sections of the evaporator tubing. This will slow the circulation of hydrogen and ammonia gas, or in severe cases, completely block it, resulting in a loss of cooling"

[2oldman]

Bobbo wrote:
(Others will have a better grasp of the details, but that is the overview.)

LOL.. I'd give that presentation an A!

[Gdetrailer]

RV fridges work on the principle of gravity.

In order for gravity to work the tubing is designed to work MOST efficiently when the fridge is fully within the bubble. Running half bubble or fully outside the marks will slow down the coolant or even stop the circulation altogether.

Slowing down or stopping the circulation increases the risk of overheating the boiler which in turn breaks down the coolant and it starts to crystalize and clog the small parts of the tubing.

While there are many on this forum which will argue that it is perfectly fine to run out of level due to "redesigns" made by the manufacturers it is not those folks money which will be used by you to replace or repair your fridge.

It is a $1500-$2500 item to replace and even a rebuilt cooling unit runs for $600 not including labor.

I would not recommend even half bubble out but thats me and I don't like gambling with my money...

[Bobbo]

The ammonia is in solution in your cooling system. The burners vaporize it and it rises to the top of the cooling unit where it cools and precipitates out. Then, as it runs down it absorbs heat from the freezer/refrigerator. If the refrigerator is too far out of level, there are low points in the path where the ammonia solution is running down causing the liquid to pool. The pooled ammonia solution then dries and cakes the inside of the tubing reducing its diameter. The dried, caked materiel does not re-dissolve. Over time, it continues to restrict the tubing until it blocks.

So, yes, the damage is cumulative.

(Others will have a better grasp of the details, but that is the overview.)

[2oldman]

Yes.