Originally Posted by gasman6674
Your still getting secondary combustion air at the surface of the burner
Yes that would make sense.
Anyway I did some research and found this on ehow. My conclusion is that at the -40 I spoke of it may be more of a low pressure issue than air density.
Anyway who is going to use an rv at those temps. You will have bigger issues than propane to deal with. I don't even like to ice fish at that temp. Only happens when we have a trip planned and the weather turns on us. At -20 you can work with stuff. At -40 I do not want to try fixing anything like a skidoo that won't start.
Similarities Between Propane and Water
Liquid propane and water act similarly when temperature drops, but their boiling points differ. At sea level, propane begins to boil at a temperature of -44 degrees Fahrenheit and produces propane vapor, while water boils at 212 degrees F and produces water vapor. As the temperature drops below 212 degrees F, water stays in liquid form, it doesn't change to a vapor. Similarly, as the temperature outside the propane tank drops and approaches -44 degrees F, less propane boils inside the storage tank producing less vapor and a lower pressure.
As the pressure inside the propane tank drops, it eventually becomes too low to light a furnace or other appliance. At -44 degrees F or lower, propane stays as a liquid, there is little vapor and propane appliances won't function properly. Therefore, for appliances to work correctly, a propane tank must usually be kept in an area with a temperature greater than -44 degrees F.