Originally Posted by RSB333
My brother spent three months on the beach in his RV using propane refrigeration. When I told him I'm about to invest in solar panels
and new bimini
so I can run refrigeration, he asked why I don't go with Propane Refrig. I haven't seen any marketed as "marine grade" but since they are popular in RV's why aren't they used in boats?
I have owned two RVs for a combined total of over 10 years, having sold
my Airstream just over a year ago. Both had propane fridges. I also have had several friends who had propane fridges in remote
houses/cabins where electricity was unavailable in the 1980s and 1990s.
I see propane fridges as a technology whose time has come and gone. Today's solar panels
make them obsolete.
Propane fridges do work. As noted upthread they are expensive. You can get several weeks out of a propane cylinder, more or less, depending on the size of the fridge and the size of a propane cylinder.
In the 1940s through 1990s before there were good, affordable PV panels they were a godsend for remote
cabins, because with a standard 500 gallon propane tank you could run them year around, and they worked. For RVs, similar deal, usually smaller fridges, but again they did work and by the 1990s they had electronic ignition and electronic controls and really did work very well.
There are a number of problems. They are short lived and maintenance
intensive. On an RV with motion and vibration and so on you might typically get 10 years out of them with regular use. In a house or cabin
they last maybe 20 years. They don't cool as well as compressor
systems and take a long time to start. On a hot day where you're opening the fridge to get stuff out fairly frequently the temperature might not get below 55 degrees F. If you put a load of groceries in that warmed up since they came out of the cooler at the store it might take several hours to cool them back down.
Gas fridges are convection systems that work best when level and are sensitive to wind
which affects cooling
and can also blow out the flame. Newer systems are less sensitive to this but are still affected. Some newer gas fridges are installed with pancake "computer" fans to provide a little extra air movement if a modest amount of DC power is available to run the fan. But the fridge as a whole puts out a good deal of hot air and has to have a large chimney and air intake to work properly.
Generally the space has to be designed around the fridge.
Originally Posted by psk125
The point that they don't "like" slanted surfaces brings up the question: is there a danger of gas asphyxiation if the pilot light goes out because the boat is heeled too much? Wasn't this a problem with propane water heaters at one point?
Gas fridges have never had pilot lights.
The newer ones have electronic ignition and controls, using a spark to light the main burner, with a flame sensor to confirm ignition. Older ones had thermostats that would change the burner flame between "high" and "low" based on temperature; the "low" flame would still provide some limited cooling. There were thermocouple safeties so the gas would shut off if the flame blew out, which was common on a windy day.
The problem with off-level operation is that it interferes with convection movement of the refrigerant mixture. You get gas bubbles blocking the flow and then the boiler portion overheats leading to progressive blockage and failure. It is generally not a safety
problem but rather one that leads to early, expensive repairs