Dometic Fridge Concerns

[rockfordroo]

Originally Posted by jstaffon

Yeah, I knew what he meant though. He meant to say turbulent air flow as apposed to laminar air flow. I think if I install a baffle at the top, I'll get laminar air flow all the way up through the fins from the boards and then directed out the vent by the baffle. Thanks!

Actually, turbulent air flow removes heat better than laminar air flow. With laminar air flow, the laminations create an insulating barrier to the rest of the air. That's why I suspect (i.e., I hope) he meant "stagnant."

[jstaffon]

Originally Posted by 5picker

You could, I chose not to but have read where many have. The down side would be you'd almost need to put a connector in the wiring so if you wanted to remove the vet cover you could unplug the attached fan. Simple enough.

I cut a hole and mounted mine to the boards. (see modification of your photo for placement)

I figured the extra couple inches away from the vent surface would allow more air flow than mounting directly to the vent cover since there is a considerable amount of blockage to the fan from the solid horizontal bars molded in the vent cover if the fan was mounted directly to it.

I mounted it off to the side instead of centered in case I needed to mount a second one. Once installed and seen how well it worked, I didn't feel the need for two at the top.

I placed my lower fan flat on a couple 1" standoffs so the air blows up the back side of the fridge pulling in air from the lower vent cover.
The top fan is vertical so it blows out the vent cover.

I'd snap you some photos but my slide is currently out and is only about 8" from the side of my garage outside wall and I can't squeeze in there to take pictures. I will do it next time I put the slide in.

I hear you! My camper is in a storage space with a wall on one side. Mines about 12 inches away from the wall with the slide in. No way to get at mine either. I'll being heading out soon so I'll take a closer look in a couple weeks.

Maybe I'm being too picky on the upper fan location, but, I thought the boards were to direct the air flow up high enough in the stack so it flows thru the fins. It might just be the angle but your hole looks like it's below the fins. Wouldn't that short-circuit the air flow to have much of it bypass the fins?

Good point on not attaching the fan to the vent cover. That could be a pain. I might build a bracket and attach the fan to the upper portion of the boards so that the fan sits above them. I'll have to make sure it's sturdy enough to not flex and move around during transport. Would have been so much easier if Forest River had thought through the installation and did the right thing in the first place. Pretty disappointed in the design. I'm an engineer and this stuff just ticks me off.

[jstaffon]

Originally Posted by rockfordroo

Actually, turbulent air flow removes heat better than laminar air flow. With laminar air flow, the laminations create an insulating barrier to the rest of the air. That's why I suspect (i.e., I hope) he meant "stagnant."

Huh, ok, I didn't know laminations were created. I was just worried about a decrease in air flow out of the vent if it flows up and into the flat top of the stack instead of flowing into or onto a curved baffle. I thought that's what the baffles were for. There's a lot to figure out. Thanks!

[rockfordroo]

Originally Posted by jstaffon

Huh, ok, I didn't know laminations were created. I was just worried about a decrease in air flow out of the vent if it flows up and into the flat top of the stack instead of flowing into or onto a curved baffle. I thought that's what the baffles were for. There's a lot to figure out. Thanks!

Laminar flow is good for getting more air through a given area. Turbulent flow is good for removing heat. So we have two opposing desires. We'd like laminar flow to get air to the fins and away from the fins, but we'd like turbulent flow around the fins. If the baffle is designed properly, it will create a smoother path for the air, so the air flow (cubic ft per min) - ideally ALL of it past the fins - will increase. All things being equal, more air flow = more heat removal. If the baffle does that, you're in good shape. If the baffle is just a "block" that doesn't really help to improve flow, then you get stagnation (some air just going round and round) and the air flow drops. So the discussion of a curved piece at the top to direct the flow out of the side grill is a good one for smoothing out the air flow at the top.

[jstaffon]

Originally Posted by rockfordroo

Laminar flow is good for getting more air through a given area. Turbulent flow is good for removing heat. So we have two opposing desires. We'd like laminar flow to get air to the fins and away from the fins, but we'd like turbulent flow around the fins. If the baffle is designed properly, it will create a smoother path for the air, so the air flow (cubic ft per min) - ideally ALL of it past the fins - will increase. All things being equal, more air flow = more heat removal. If the baffle does that, you're in good shape. If the baffle is just a "block" that doesn't really help to improve flow, then you get stagnation (some air just going round and round) and the air flow drops. So the discussion of a curved piece at the top to direct the flow out of the side grill is a good one for smoothing out the air flow at the top.

Cool! ... No pun intended... I've got some good direction from you guys. Thanks so much for the interest in my post and the help you've offered!