06-09-2013, 08:19 AM
If you read on the internet the concern is often raised about using too small a propane tank. The propane is stored as a liquid but must evaporate before it leaves the tank. In doing so it cools the rest of the tank. Heat must be conducted into the remaining liquid from the ambient environment. As the liquid in the tank shrinks to a mere puddle in the bottom the surface area of the blob of liquid decreases until the heat transfer can't keep up. For very high demands even a relatively full 20 lb tank doesn't provide enough surface area or so I have read. My heater has a fairly high capacity of over 100,000 btu/hr so I have been concerned. According to the folks at Hilo Propane I will have no problem. They have never seen it happen. Of course it never gets very cold in Puna. How cold is too cold? Apparently at -40 deg F you can carry liquid propane around in a bucket like water. Its vapor pressure at -40 is the same as ambient, similar to water at 212.
The first visible symptom is that frost will start to form on the outside of the tank Anyone ever seen this here?
The first visible symptom is that frost will start to form on the outside of the tank Anyone ever seen this here?