Monday, June 19, 2017

Why your refrigerator may not work on propane above 8,000 feet.

From a RV tech:

There are no adjustments to anything that will make a difference. Removing the protective cover around the burner housing to allow more air to get to the burner might help because the problem is a lack of oxygen and cold temps.

This explains what's happening.

Propane gas will only ignite when the turbulence from jet causes the propane to mix with the air as it shoots out of the orifice.
Propane ignition requires at least 2.15% but less than 9.6% propane gas.
At high altitudes, there is less air so the normal orifice is slightly too large and delivers too much propane.
If the temperature of the tank is also low, the propane density is increased and the 9.6% limit is exceeded.

Propane Limits of Flammability - The lower and upper limits of flammability are the percentages of propane that must be present in a propane/air mixture. This means that between 2.15 and 9.6% of the total propane/air mixture must be propane in order for it to be combustible. If the mixture is 2% propane and 98% air, there will not be combustion. If the mixture 10% propane and 90% air, combustion will not occur. Any percentage of propane in a propane/air mixture between 2.15% and 9.6% will be sufficient for propane to burn.

Contributed by Ed Daniels