No Refrigeration At High Altitudes
Dear RV Doctor:
I have been camping at high altitudes in Colorado for 40 years and never had a problem until I bought a new motorhome recently. The owners manual for my Norcold refrigerator says that in gas mode it may not work above 5,500 feet elevation. Nice to know after I bought the coach! I find it strange that none of my friends who also have Norcold refrigerators seem to have any problems. Do you have any suggestions?
Bill Devine
Boulder, Colorado
It’s true; some of the newer Norcold refrigerators may have difficulty operating at high altitudes, but it affects the refrigerators only when operating on propane. It should not pose a problem when operating on 120-volt-AC electric. In past years, Norcold offered kits and alternate burner orifices to reduce the flow of propane and enable it to mix properly with the much thinner air at higher elevations. I surmise that the company, hedging more to the safety side of the equation, simply nullified the potential of using propane as the heat source in an absorption refrigerator. In most cases, it’s not safe or justifiable for RV owners to modify gas flow components in propane-burning appliances without the benefit of proper training. The company now includes a warning statement in the owners manual that reads:
When you operate the refrigerator on propane gas at altitudes higher than 5,500 feet above sea level:
– You may experience reduced cooling performance of the refrigerator.
– You may experience burner outages.
To avoid these possible problems, Norcold recommends that you operate the refrigerator on AC when at altitudes higher than 5,500 feet above sea level.
Keep in mind, this may not be the case with all models of Norcold refrigerators. Some RVers report no problem at higher elevations, but it seems more prevalent with the newer models.
Absorption refrigeration has strict limits when it comes to the applied science of physics. As an example, when the ambient temperature dips very low, an appliance may outrun its own rate of propane vaporization, rendering it useless at temperatures below freezing while trying to operate on gas. At higher elevation, the air is thinner, but that does not negate the fact that propane must still mix with that air in order to burn completely. Less air results in an overly rich mixture that drastically affects the operation of the refrigerator, which relies heavily upon the convergence of temperature, pressure, and vaporization. It’s simply an “RV Fact of Life” concerning absorption refrigeration. Thankfully, it affects only the propane function. When it’s possible, plug into a 120-volt-AC electric power source or run the generator. If you have a predilection for dry camping, it might be wise to consider installing an inverter with a stout battery bank as an alternative.
From what I’ve researched, the warning in the owners manual says that issues will be encountered at 5,500 feet, but problems usually don’t surface until 7,000 feet or so. Once you begin having issues, removing the outside access door to allow more free-flowing air to enter at the back of the refrigerator may help in the short term. Eventually, though, the propane function will stop working as you climb higher. While this answer may not help you alleviate your refrigerator’s high altitude issue, at least you now know why it is occurring.
Yellowed Moldings
Dear RV Doctor:
I hope you can help me with this problem, because it’s driving me crazy! We are longtime full-timers. We have an older motorhome that we try to keep in ”as new” condition. The front and rear caps are fiberglass, and the sides are full gel-coat. On all four corners where the caps join the sides, there is a joint. Newmar used a hard rubber molding running vertically to cover this joint. This molding does not slide into a track. It is a standalone thick molding that is somehow attached to the body to cover the joints. Over time, these moldings have turned yellow from sunlight exposure. I found that using an SOS pad would remove this yellowing. At first, this was required every six to eight months. Now the yellowing returns in as little as two months. I’m getting too old to do this every other month! Have you seen this problem before? Do you know of an easier way to remove the yellowing and stop it from occurring?
Bill Kerr
Arizona
There are literally dozens of products available that manufacturers claim can rejuvenate exterior surfaces, but the success rate can truly be subjective. In your case, how you tackle the problem depends on what is actually causing the yellowing. Is it oxidation of the base material? Perhaps the cement used to attach the molding is off-gassing? True, the sun (and heat) is typically the cause, but it also could be the reaction of the composites in that type of plastic. Some say it’s caused by bromine used in the mix.
As for an easier way to clean them, I had one person suggest using hydrogen peroxide. I had another FMCA member tell me he had great success using CRC Brakleen (non-chlorinated) Brake Parts Cleaner. Others have told me they had success with Simple Green. Spray it on a clean, cotton cloth and rub like crazy. Another said he had success using a common cleaning pad.
Personally, I haven’t taken the time to put these theories into practice, but they may be something you could try. Since I’ve had good success with 3M products, I’d probably try cleaning the oxidized surface of the moldings with a 3M Scotch-Brite Ultra Fine Hand Pad.
I think the reason the moldings are turning yellow faster now that you’ve cleaned them several times is because as you remove the yellowing on the surface, there is nothing to prohibit the advancement of the oxidization, which continues unabated. I’d try the 3M pads, and then apply a carnauba wax protectant of some type. It’s imperative to block the damaging UV rays and ozone from attacking the surface of the moldings after they’re clean.
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