How often to run the engine in a Centurion?

[jdmcm]

Also a handy item for keeping interior moisture at bay is a boat air dryer, you leave them plugged in and they give off just enough heat to keep things dry, I used them a fair bit when I had my trucking outfit. If you had a truck sit too long during winter here on the coast, the interiors would become damp and soon start to grow a nice furry green mold. The air dryer took care of that in short order. Perhaps 2 in a big tank like a Centurion, maybe one in the drivers hole and the other in the fighting compartment? So far I have a small electric heater with a thermostat that does roughly the same thing.