ernie1 wrote:
NRALIFR My refer has two side vents and I've installed two 12v fans behind the top vent and when the fans are running I've actually noticed the refer losing ground and the inside warm up a degree or two so now I've quit running the fans totally. You're right about reading the installation manual and I will but I'm still saying if the installation was not proper, why does the unit run fine on ac and 12v BUT not propane. Also, My two friends with Dometics of the same vintage complain about the same issue. Logic is clear to me in this case that there is something not right with the propane part of these refers. I'm tired of hearing about how blameless Dometic is and when I reach out for help to their tech people they are clueless, rude and condescending. At this point I think I'm beating a dead horse in trying to find a solution and getting wound up in company loyalty issues etc rather than dealing with facts.
Your logic is correct. I know you’ve mentioned that it works fine on AC more than once but I forgot that when I made my last post. I would check the LP pressure before doing anything else.
All I can say regarding fans is that on my current unit, I have one fan in back, and it’s mounted about halfway up in an area where there’s a lot of room between the tubing. It’s pointing up, blowing through the condenser fins at the top, and the roof vent above it. It’s actually a fairly slow speed, quiet fan. You can hardly hear it. I don’t think high speed fans are necessary back there.
One thing that is different about running in LP mode versus AC mode, is the waste heat from the flame coming out of the chimney. There are more btu’s of heat to exhaust out the top vent when the fridge is running in LP mode than when it’s in AC mode. The baffle at the very top of the fridge should direct all of the heat coming off the cooling unit tubes and fins AND coming out of the chimney to the top vent, and not let any of it enter the dead air space that’s typically left on top of the fridge. If there’s even a small gap at the sides of the top baffle, heat will enter the area behind it. I’ve found that it’s best to fill that area with insulation to prevent that.
The heat produced by the flame doesn’t all go into the boiler perk tube of the cooling unit like it does when running in AC mode. The chimney should have a twisted strip of metal hanging down close to the bottom called a baffle. It’s supposed to concentrate the heat in the proper area so the solution inside the perk tube will boil. If that baffle isn’t there, the heat just flows up the chimney and the boiler doesn’t get hot enough. Even with the baffle though, there’s a lot of heat flowing out of the chimney. Enough to burn you when the flame is on. So, make sure the baffle is there, and that the end closest to the flame isn’t burnt off. Make sure there’s nothing obstructing the flow of heat coming out the chimney. Also make sure the chimney is clean of rust. A 10 gauge shotgun wire brush can be used to clean it. Of course you have to pull the baffle out for that.
Here’s an image of a cooling unit I like to refer to. You can see a representation of the baffle in the lower right. It looks like a figure eight.
:):)
