Absorption fridge tests and new safety device
I have been stating for YEARS that operating an absorption fridge off level of ANY AMOUNT affects the fridge in a bad way... Well, I noticed on a different RV forum that there has been some testing...
Forum Discussion
I should clarify what I learned during the ARP field testing and the "long term damage" claim.
It became evident that the cooling unit functions perfectly fine until the tilt reaches a point where there is insufficient return flow to the boiler, and then the boiler temperature skyrockets past the point where temperature damage (crystallization of the sodium chromate) begins to occur. That degree of tilt is not something the RV owner can readily determine and it differs by fridge make/model and the direction of the tilt, so there is no useful "rule of thumb" except to keep it as level as possible. Most of us encounter some brief periods of off-level operation during travel, during rest or fuel stops, checking in at a campground office, etc. and each of these may trigger a high temperature episode. It's a classic "death of 1000 cuts", so some RV owners will never accumulate enough "cuts" to cause a total failure while others might reach the critical point fairly quickly.
So, those who say they don't have problem with off-level operation or high boiler temperatures may indeed be right. The concern is that none of us really know where we currently stand with respect to the damage threshold or how often we will add more high temperature events in the future. With an ARP doing both the monitoring and preventing an over-temperature condition, this source of potential future failure is eliminated. The value of that level of protection is something only you can decide.
The thing that bothers me the most is that the fridge makers could have easily and cheaply built in this level of boiler management and off-level protection. All the RV fridges made in the last 20+ years have circuit boards that could easily include the monitoring function and the temperature sensor for the boiler is only a few dollars in mass production quantities. The increment to the fridge selling price would be tiny, if any. If Norcold had built in ARP-like monitoring, they would not now be pouring millions of dollars into the 1200-series fire recall and compensation for victims of the failures. Dometic has had similar fridge issues, though not on the same scale that Norcold has had. It seems to me this was all preventable.
It became evident that the cooling unit functions perfectly fine until the tilt reaches a point where there is insufficient return flow to the boiler, and then the boiler temperature skyrockets past the point where temperature damage (crystallization of the sodium chromate) begins to occur. That degree of tilt is not something the RV owner can readily determine and it differs by fridge make/model and the direction of the tilt, so there is no useful "rule of thumb" except to keep it as level as possible. Most of us encounter some brief periods of off-level operation during travel, during rest or fuel stops, checking in at a campground office, etc. and each of these may trigger a high temperature episode. It's a classic "death of 1000 cuts", so some RV owners will never accumulate enough "cuts" to cause a total failure while others might reach the critical point fairly quickly.
So, those who say they don't have problem with off-level operation or high boiler temperatures may indeed be right. The concern is that none of us really know where we currently stand with respect to the damage threshold or how often we will add more high temperature events in the future. With an ARP doing both the monitoring and preventing an over-temperature condition, this source of potential future failure is eliminated. The value of that level of protection is something only you can decide.
The thing that bothers me the most is that the fridge makers could have easily and cheaply built in this level of boiler management and off-level protection. All the RV fridges made in the last 20+ years have circuit boards that could easily include the monitoring function and the temperature sensor for the boiler is only a few dollars in mass production quantities. The increment to the fridge selling price would be tiny, if any. If Norcold had built in ARP-like monitoring, they would not now be pouring millions of dollars into the 1200-series fire recall and compensation for victims of the failures. Dometic has had similar fridge issues, though not on the same scale that Norcold has had. It seems to me this was all preventable.
