Refrigerator vent question.

[bsaa10bill]

I'm installing a taller refrigerator in my '68 Safari and I'm going to make an aluminum vent for it. My question is , does the refrigerator need to be sealed to the wall from the bottom along the rear edges or can the vent start at the top rear of the fridge? The vents I've seen only seem to go from the top rear of the fridge up, but couldn't that let exhaust gas escape from the sides, or would the hot gasses always go straight up?

[Aviator]

The vent is not for gasses, but for warm air. The system works due to air entering at the bottom back of the fridge, then passing over the "fins or heat exchanger", warming, and exiting via the roof vent.

Your vent plenum only needs to stretch from the top of the cooling fins to the vent through the ceiling. The sides of the fridge need to be sealed to ensure the airflow is uniform in movement from beneath the fins to the roof.

[TG Twinkie]

I disagree with Aviator. The back of the refer as well as the vent stack should be sealed off from the living quarters.
There is a propane fired burner which emits CO fumes which could enter the living quarters if circumstances are right.
The furnace in an RV has a sealed combustion chamber. Meaning the combustion air is drawn from outside and the exhaust fumes are delivered to the outside thru the exhaust pipe. This is to prevent the furnace from using cabin air for combustion and to prevent exhaust gases from entering the cabin.
Even though the refer has a smaller burner the exhaust gas entering the cabin could make you sick or possibly kill you and anyone or living thing inside.
It's always a good idea to play it safe.
A CO detector is a must.

[Tom Nugler]

Lets look at how the fridge is installed.
On both my '67 and '72 the fridge was installed above the floor vents in what could be considered an extension of a cabinet. The sides were secured to the inner skin with extrusions but certainly not sealed. The large size of the vent stack is for cooling the condenser coils. Additionally the burner chimneys were so close to the plastic vent stack the exhaust gas would appear to travel directly up the inner wall vent to the roof vent.
My '72 had an option for either a tall or short fridge with only minor change to the cabinetry. I would be more concerned that the vent to the roof was well secured to the inner skins than trying to seal the enclosure airtight to the trailer interior. A sealed compartment is a greater concern with the newer rigs that vent out the side and not the top.
I assume the designers considered the convection currents generated with a roof vent were sufficient to carry any CO safely out of the trailer. If you are still concerned there have been threads posted here on adding circulating fans to increase airflow up the stack that would also carry away any CO when running on gas.

Tom.

[TG Twinkie]

Back in the 70's, like in my '74 Argosy the back of the refer was not sealed off from the cabin. The vent (plastic) also was not sealed. Just riveted to the wall. The floor vent provides fresh (combustion) air as well as draft air. The exhaust stack carries the heat away (hot air rises). But only if there are no outside influences. I don't mean literally.
Consider the fact. You have a shower, then turn on the exhaust fan to get rid of the moisture. You fail to open a window or door. The fan causes a negative pressure in the cabin which will draw outside air in wherever it can. Leaks around windows, doors and the refer exhaust stack as well as the floor vent. The air drawn in will take the path of least resistance. Pulling the heat and CO fumes into the cabin.
I don't believe there was any designing done for this type of safety issue. Remember these were the days of standing pilots on stove tops as well as ovens.
So you have had your shower the exhaust fan is running and so is the A/C. Now you are pulling the hot air from behind the refer into the cabin. Making the A/C work harder. ??????
Seal it up for safety and efficiency. Install a CO detector.
We didn't have seat belts back in the 70's or Airbags.
Just because they did it that way 50-60 years ago doesn't mean it was right or safe.

[shannon]

On this same general subject, I am looking for anyone's photos* of a refitting of a new fridge into around a '70 Safari -- specifically the base mount for sitting the fridge on to clear wheel well. I will have to build one to elevate our new fridge right next to the door.
I would also like to see (*I'm a photographer, so seeing is important to me!) anyone's images of add-on computer fans in the refrigerator vent stack - how powered / how mounted.

[batman]

First of all, the space around the refer and vent system should be sealed to the inside of the trailer for safety. The combustion chamber on the refer must be vented through the top vent. There must be a source of outside air for the propane burner to use. NOT cabin air. This should be a closed system!

Here are some photos of my 64 Safari renovation. A little different than yours but I hope these help. You can see my original vent from the outside was half way up the wall. I closed that off. The refer relies on a convective air flow. Heat rises and draws cool fresh air from the outside vent. In speaking with more than a few professional restoration folks, Uwe at Area63productions, ETC. I decided to vent through the floor for my fresh air intake vent. Better convection from down below the burner up through the fins and out the top. In one of the photos you can see the carbon from the original top vent. It all need to be sealed from the cabin air!

-Dennis

[batman]

I also made a new top vent plenum. This may give you some ideas.

Best of luck with your project.

-Dennis