Yes, this is a closed loop system. Since I have ready access to the engine I take air out of the breather tube and return air via the oil filler tube.
It's been running since early Feb. and seems not to have a problem staying cool, but as you've mentioned already, Western Oregon isn't the warmest place on earth. There is so much desicant in this little air drier that I feel there is huge capacity to collect moisture. I have BB sized pellets of Cobalt Chloride (the Blue indicator that turns pink with moisture) mixed in with several different grades of Silica Gel and the pellets show no sign of turning pink, they remain bright blue. It's worth mentioning that the Cobalt Chloride will turn pink long before the Silica Gel needs to be dried out. If this were an open system I have no doubt the gel would need dried out every couple of weeks. I used to have inline throw away air driers, which as it happens are the source of the BB sized pellets of Cobalt Chl. I had taken one out of its' packaging but not used it having set it on a shelf in my shop. Within a week the pellets had turned pink. That was at zero air flow. Any moisture entering the filter had to cross a sintered brass air filter, one on each side of the canister, then across the pellets. Moisture seems to be a pervasive thing.
It's been running since early Feb. and seems not to have a problem staying cool, but as you've mentioned already, Western Oregon isn't the warmest place on earth. There is so much desicant in this little air drier that I feel there is huge capacity to collect moisture. I have BB sized pellets of Cobalt Chloride (the Blue indicator that turns pink with moisture) mixed in with several different grades of Silica Gel and the pellets show no sign of turning pink, they remain bright blue. It's worth mentioning that the Cobalt Chloride will turn pink long before the Silica Gel needs to be dried out. If this were an open system I have no doubt the gel would need dried out every couple of weeks. I used to have inline throw away air driers, which as it happens are the source of the BB sized pellets of Cobalt Chl. I had taken one out of its' packaging but not used it having set it on a shelf in my shop. Within a week the pellets had turned pink. That was at zero air flow. Any moisture entering the filter had to cross a sintered brass air filter, one on each side of the canister, then across the pellets. Moisture seems to be a pervasive thing.