Time to replace defective and potentially dangerous absorption fridge

[oldmansax]

(07-05-2013 10:32)gondolaguy Wrote:  Tom,

Good to hear from an expert on these technologies.

What I extracted from your post actually increased my fear of these poorly designed products (even if the technology is sound!) I gathered: a) our RV refers are not built or installed to good standards in almost all cases, b) you recommend owners pull and inspect the ammonia cooling units (most won't until there is an issue, I'll bet) and c) you will fireproof your enclosure when the next refit happens. Not very comforting!

As far as the rumor...
"When asked why Norcold did not contest the claims that their products caused all the fires, some RV dealers and service people said the RV manufacturers threatened to ruin Norcold with a PR campaign and never use any Norcold products again."
...this smacks of backroom mechanic's theory versus real-world manufacturing business practice (my area of expertise).

Not sure I would qualify as an "expert" unless we use the old definition "An expert is just a drip under pressure!" I do, however, qualify as a "professional" since that is anyone who gets paid for what they do. LOL!
Let me comment on your comments....

A-- I don't want to paint all manufacturers with the same brush but it does appear that, while the units DO meet the standards, the standards are somewhat lower than what we expect. Camper manufacturers then exacerbate the lower standards by poor installation. I have to admit I was EXTREMELY disappointed when I pulled the original fridge in my PT and found it was not installed according to specs. I really expected better from Wanderlodge. Equipment standards happen to be one of my pet peeves. I could write a book but nobody wants to hear about it. Suffice to say while the technology in many areas has improved, the equipment standards have been lowered more and more until you really have to read the fine print to see what the performance actually is. Even residential refrigeration and air conditioning has suffered the same fate. Years ago a 3 ton unit would actually produce 36,000 BTUs of cooling at any ambient temperature usually encountered in the US. Now I frequently find units that, not only will not produce 36K, but will not even produce their sub-standard rating above 90F!! I'm gonna quit now before I start pounding on my desk and frothing at the mouth!

B-- Owner maintenance of these units consists of cleaning the burner & flu, visually inspecting the condenser coil and air passages, and clean if needed. Don't forget the roof cap. Are the cooling fans (if so equipped) clean and operational? Also look for corrosion, particularly in welds and joints. The components of the refrigerant fluid in these unit is somewhat corrosive anyway and more so when they separate during long periods of disuse. To my knowledge, no definitive studies have been done, but, most techs agree it's better to run these units to keep the refrigerant mixed than to keep them shut off and have the components separate and cause corrosion. This also keeps the evaporator from rusting on the outside. I posted a link for better understanding at the end of this post.

C-- I already fire-proofed (really more like fire-retarded ) my enclosure but I like the Hardy board idea better.
As to the rumor, I will quote The Shadow: "Who knows what evil lurks in the hearts of men?" Sorry, I can't do the maniacal laughter that should follow.

(07-05-2013 10:51)davidmbrady Wrote:  Have you had a chance to look at and assess any of the replacement aftermarket cooling units?
Tom, any idea on the quantity of ammonia and hydrogen in the units? We want the backerboard to withstand any flame until all the fuel is consumed.

No, I have not seen the aftermarket units but I really want too, particularly the Amish models. I think heavier is better, as far a cooling units go.
Quantity of refrigerant would depend on unit size but basically these units have a few ounces of ammonia, water and rust inhibitor, and then the unit is pressurized to around 350# with hydrogen. Here is some information on how these units work:
http://www.gasrefrigeration.net/why%20they%20fail.htm

TOM