172bh Hike fridge question

[Esparent]

Hey all,
First real post. We just took our Hike out for our first real trip and tried most of the systems out for the first time. We have a dometic propane/electric fridge. It works well on electric mode as far as I can tell. I wanted to try the propane mode out as we are planning on doing some dry camping this summer.

I switched it to gas mode and unplugged the trailer from shore power (we upgraded the battery to a 100AH Renogy lithium). Shortly we began getting a “hot” smell in the camper. Not quite like burning or melting plastic. I opened up the two vents on the slide to check it out and am wondering if this all looks right or not. This piece of very thin (1/8”?) plywood is nearly touching the fins and vent stack/chimney.

I just want to make sure this is safe and correct. I don’t really know what that piece of plywood would be doing there but I assume it must have a purpose if it is there.

Thanks for the help!

[Fred 2106DS]

Originally Posted by Esparent

Hey all,
First real post. We just took our Hike out for our first real trip and tried most of the systems out for the first time. We have a dometic propane/electric fridge. It works well on electric mode as far as I can tell. I wanted to try the propane mode out as we are planning on doing some dry camping this summer.

I switched it to gas mode and unplugged the trailer from shore power (we upgraded the battery to a 100AH Renogy lithium). Shortly we began getting a “hot” smell in the camper. Not quite like burning or melting plastic. I opened up the two vents on the slide to check it out and am wondering if this all looks right or not. This piece of very thin (1/8”?) plywood is nearly touching the fins and vent stack/chimney.

I just want to make sure this is safe and correct. I don’t really know what that piece of plywood would be doing there but I assume it must have a purpose if it is there.

Thanks for the help!

That's interesting. I've never seen anything like that before. My guess it is a piece of baffling that fell from up near your top vent that is used to direct the airflow out your top vent. Here's a picture of what our Dometic propane/electric fridge looks like when the lower vent panel is removed, no plywood here. Though I did add an ARP system to protect the refrigerator from catching fire incase something goes wrong and it does start to overheat.

[Esparent]

That’s somewhat similar to the lower vent I have, there are two of equal size.

That piece of plywood is staples/nailed where it is but is warping a bit, bringing it almost into contact on the fins and flue.

[Fred 2106DS]

Originally Posted by Esparent

That’s somewhat similar to the lower vent I have, there are two of equal size.

That piece of plywood is staples/nailed where it is but is warping a bit, bringing it almost into contact on the fins and flue.

Sorry, My bad. I didn't look close enough at your pictures. I thought it was a picture of your lower vent. Here's a video that explains what Winnebago is attempting to do with that piece of plywood in the upper vent, though this tech is using metal sheeting to do the same thing.

https://www.youtube.com/watch?v=DxUn...1sKbB&index=21

[Bones2003]

Esparent, it is good to be paying attention to hot smells coming from your fridge so I applaud you for that.

Is your camper a brand new unit and this is the first time the refrigerator has been used on propane? If so, it could just be the "new" gassing off the various parts from the heat in the flue. A lot of times the assembly techs will touch various parts with grease or oil on their hands or there is oil used in the forming equipment that doesn't all get washed off. That stuff will smell hot until it completely evaporates.

It looks like your top refrigerator vent is on the wall of your camper. All of my campers had the vent on the roof so I can't tell you if that wooden baffle is normal or not. If your camper is new, I would assume it is normal since it is stapled in. If it is an older used unit, maybe the previous owner added it for some reason. I would be suspicious if it was added by the previous owner.

And finally, it looks like they used plenty of that spray foam insulation that is close to the flue. You might trim some of that back if it is not needed. Maybe that is outgassing as well.

[Esparent]

Wow, that video is exactly what I needed. I figured it must help with draft but wasn’t sure. I don’t like how the wood is touching hot elements, especially the flue, so I think I’ll copy this guy and use some flashing to improve air direction and put a noncombustible barrier between those hot elements and the spray foam, wood, etc. I’ll try to post an update when I do that.

Any other thoughts on the situation are welcome!

[Fred 2106DS]

Good air flow is the key to keeping your absorption fridge running efficiently.

I'm able to remotely monitor and log our fridge and freezer temps and starting our fridge on electric, it will typically take 5 hours for our fridge temperatures to get to the mid-thirties and the freezer to get into single digits.

[Esparent]

So I’ve started to work on it a bit and found this when I took that piece of 1/8” ply off. Doesn’t seem like this should happen. Thoughts?

[Fred 2106DS]

Originally Posted by Esparent

So I’ve started to work on it a bit and found this when I took that piece of 1/8” ply off. Doesn’t seem like this should happen. Thoughts?

Looks like the plywood may have been setting against one of the tubes causing discoloration or slight surface charring of the plywood. The condenser area is the hottest part of the absorption system outside of the boiler area. The boiler typically operates at around 350 degrees F. but can get much hotter if operating in an off level situation. I believe most manufacturers recommend you operate adsorption refrigerators within 3 degrees of level except for short periods of time, such as when traveling.

[Esparent]

That spot of discoloration was right against the propane flue. I’m replacing it with metal flashing with an air gap. The pic attached is not done yet, need to add the upper section

[Fred 2106DS]

Originally Posted by Esparent

That spot of discoloration was right against the propane flue. I’m replacing it with metal flashing with an air gap. The pic attached is not done yet, need to add the upper section

Now that you have removed the plywood, have you tried the refrigerator on propane? If so, has the "hot" smell gone away?

[Esparent]

Not yet. I’m expecting some odor because it’s barely been used. But it seems the way it came from the factory was not ideal, so that’s what I’m fixing.

[Esparent]

Here is the remodeled fridge vent/ducting area. Still haven’t had time to fire it up. Hopefully tonight I’ll get to that.

[Fred 2106DS]

Originally Posted by Esparent

Here is the remodeled fridge vent/ducting area. Still haven’t had time to fire it up. Hopefully tonight I’ll get to that.

Your baffles look much better than OEM. Good luck with your testing!