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Tincup · 03-25-2008, 05:16 AM

While installing wiring for an Air X wind turbine I had the need to remove the reefer vent on the roof to snake wires down. While in the rig pulling wires I noticed a burn area on the ceiling material behind the reefer. Upon further investigation on the roof I discovered the source. The exhaust stack was about 4 inches to the leftleft of the large vent cut out of the roof. I'm talking about severe burning of the ceiling material down to the plywood base the ceiling stuff is glued to. The plywood was too hot to hold your fingers on for more than a few seconds. Talk about a fire waiting to ignite

. There is a deflection plate on the top of the stack but that was useless, I removed it in my repair job.

I got a section of all aluminum dryer vent pipe 3" diameter. The stuff that collapses like an accordian not the ridged stuff. I took a piece about a foot long and formed it into a gradual "ESS" and moved it to the vent area and secured it with a self tapping screw, then replaced the reefer vent cap. I can feel all the heat escaping from that pipe out to fresh air.

The next time you're on your roof, check out the stack vent location!

__________________________
| |
O | |
| |
|_________________________|

O = Referigerator vent pipe & burn

Box is the roof cut out for the vent

Tincup · 03-25-2008, 05:16 AM

While installing wiring for an Air X wind turbine I had the need to remove the reefer vent on the roof to snake wires down. While in the rig pulling wires I noticed a burn area on the ceiling material behind the reefer. Upon further investigation on the roof I discovered the source. The exhaust stack was about 4 inches to the leftleft of the large vent cut out of the roof. I'm talking about severe burning of the ceiling material down to the plywood base the ceiling stuff is glued to. The plywood was too hot to hold your fingers on for more than a few seconds. Talk about a fire waiting to ignite

. There is a deflection plate on the top of the stack but that was useless, I removed it in my repair job.

I got a section of all aluminum dryer vent pipe 3" diameter. The stuff that collapses like an accordian not the ridged stuff. I took a piece about a foot long and formed it into a gradual "ESS" and moved it to the vent area and secured it with a self tapping screw, then replaced the reefer vent cap. I can feel all the heat escaping from that pipe out to fresh air.

The next time you're on your roof, check out the stack vent location!

__________________________
| |
O | |
| |
|_________________________|

O = Referigerator vent pipe & burn

Box is the roof cut out for the vent

Tincup · 03-25-2008, 05:19 AM

My drawing didn't come out too good. Imagine the "O" 4 inches to the left of the box.

I never was good in art appreciation

Rocky 2 · 03-25-2008, 07:25 AM

Thanks for the heads up. This is precisely why this forum is so valuable.

offshore · 03-25-2008, 09:26 AM

Good catch, thanks for the information.

Gary RVRoamer · 03-25-2008, 06:26 PM

I don't think your refer should be getting that hot in the first place. I've felt the metal of the tube be too hot to toch, but never seen any of the surrounding materials get that hot in any circumstances. Are you sure it is not one of the ones being recalled? Or just plain improperly installed (the misaligned vent is a clue).

Tincup · 03-26-2008, 04:24 AM

Gary,

No, it's not one of the recalled units, I've double checked that. Judging by the inside of the rig, looking at the surrounding walls and fridge, everything is plumb and level. If anything was done incorrectly regarding the fridge installation you can't detect it. My theory is that when Fleetwood cut the hole in the roof, they were about 4 inches too far to the rear of the coach. If they moved the cut towards the front, all of the fins and the exhaust vent would have been exposed and vented properly. Keep in mind, the exhaust vent is only 1" in diameter and about 6" below the ceiling material. When you're stationary, and the fridge is in the cooling mode, that vent is almost like a small tourch. The rear of the fridge is in a confined area with no ventilation so the gases don't cool off much on the way up. When it's running, I don't think you could keep your hand over the vent for more than a few seconds it's that hot.

But it raises the question of how hot should the gases be at the vent? Time to do some Googleing

Thanks for your comment.

Gary RVRoamer · 03-26-2008, 05:10 AM

All I can say is that I've owned a dozen different RVs and never had one anywhere near that hot.

I guess I don't understand the 1" diameter vent either. Isn't the whole area at the top under the grill exposed? The cut-out is something like 4 x 15", isn't it?

Is this a Dometic fridge?

Tincup · 03-26-2008, 05:51 AM

The exhaust gas temperatures can be anywhere between 200-400 degrees F. This I got from reading Norcold installation guide, and two different patents on Gas absorbtion refrigerators. After reading them, my head is swimming. Anyway, you're right the cut out is about that dimension but the vent stack was not within that 4 x 15" it was 4 " forward of the opening. As far as the 1" diameter goes I guess I don't know what to say, it's 1" in diameter. The larger pipe you see at the back of the fridge I believe, is just a heat shield to prevent exposure to that hot 1" pipe.

Here's the installation document for my series 1200 Norcold Installation. If you go to page 11 and look at Art01597, it clearly shows how the exhaust and fins should be vented. Mine is not that way. The vent cover circled 2 is roughly 4-6" to the left in that drawing. And the 1" vent pipe is roughly where the circled 3 arrow is pointing.

I'm not making this stuff up Gary, I'm just sharing how my installation is. The fridge has worked great for the three years we've had it. If your installation is correct and you have no concerns then thats great. But in my case it was poor job of cutting the roof vent, in my opinion.

Gary RVRoamer · 03-26-2008, 06:31 PM

I'm sorry - did not mean to imply you are making anything up. Just trying to understand what you have and why it is getting hot enough to char wood. It does indeed take around 450 degrees to char wood or paper, so yours must be running up around that temp.

I too have a Norcold 1200 LRIM and I haven't noticed any excessive heat like you report. Guess I'll have to take a closer look/feel to be sure. Does yours have fans in the cooling unit? Mine come on automatically and move a modest amount of air though if it gets hot inside.

From your description I see that the 1" pipe is down closer to the cooling unit, not up by the roof vent as I previously thought. I haven't looked that far down on this Norcold fridge and my previous ones (that I have been more intimate with) were Dometics and were essentially open across the top of the cooling unit.

I think you have an excellent case for claiming an unsafe installation that does not meet Norcold factory specs. I see it does allow for offsets with appropriate baffles and such, but it does not sound like yours meets the spec.

To me, the possibility of a fire starting in the roof due to this fridge vent problem is really scary.

Fire in an RV spreads to fast to take any chances!

Gary RVRoamer · 03-26-2008, 06:50 PM

The pics in THIS thread, I think, show the 1" hose you are talking about. It is not clear to me what purpose it serves - clearly it is too small to be a meaningful air duct for the cooling unit.

RV Wizard · 03-27-2008, 12:07 AM

Tincup, by chance did you take a picture of the installation area at the top of the refrigerator. When you removed the deflection plate there should have been a small rod connected to it or the chimney itself. Did you notice this? From this rod, just above the burner there is a metal baffle hung. This baffle is used to push the heat of the flame (lp gas mode) to the outer walls of the burner area so the heat can be absorbed by the cooling unit. It must be in place for the refrigerator to normally operate in lp gas mode properly. Whithout this baffle the heat is going to go straight up the flue of the chimney and be much hotter than normal. The installation of the vent may also be on a recall and probably should be fixed by Fleetwood. In my opinion this should be investigated if you are unsure and corrected before ever using the refrigerator on lp gas again.

Tincup · 03-27-2008, 05:03 AM

In the link you provided, in the top photo if you look to the far right you'll see a fibergass insulated unit. Inside that insulation is the 1" pipe I mentioned, that zig zags its way to the top of the fridge and exists straight up and out.

For RV Wizard, that baffle wasn't effectively doing anything, I removed it, but kept it, and the fridge has been working fine. Milk is cold, Ice Cream freezes etc. We're sitting in the desert here at Slab City and it's been in the upper 80's low 90's but the fridge side is in the shade. I guess it's time to get back up there and take some pictures, I'll figure out how to post them here and should have some later today.

Again to everyone, thanks for the replys.

Tincup · 03-29-2008, 07:44 AM

Well folks, I've tried to get photos posted but frankly, 7 pages of instructions to post photos are a too much for me. I can dismantle a 4ESS telephone switch and put it back together, I can tell you in great detail how a SS7 telephone network works, but by God this photo stuff has got me baffled.

But I will never give up

, stay tuned.