Do I need this?

[DryFly]

Getting ready to install a new sink and kitchen counter. We went and looked at new Airstreams today for ideas, and I noticed the chase for the refrigerator vent isn't used anymore on the new ones. Snooping around it appears that the new AS use a 12v fan behind the refer in the access panel on the exterior.
So, is there any reason to keep this? I would really like to eliminate it. I could very easily install a 12v fan with a small switch and turn it on when I run the refrigerator on propane. Here's a photo, the arrow points to the chase I want to eliminate.
Thanks as always

[vswingfield]

That acts as a chimney that routes the combustion fumes rich with carbon monoxide (CO) to the vent on the roof.

I think it's important.

[CanoeStream]

The fan ventilated fridges are noisy at night. Really? They're doing away with the natural draft fridge vents?

[overlander64]

Greetings DryFly!

Originally Posted by DryFly

Getting ready to install a new sink and kitchen counter. We went and looked at new Airstreams today for ideas, and I noticed the chase for the refrigerator vent isn't used anymore on the new ones. Snooping around it appears that the new AS use a 12v fan behind the refer in the access panel on the exterior.
So, is there any reason to keep this? I would really like to eliminate it. I could very easily install a 12v fan with a small switch and turn it on when I run the refrigerator on propane. Here's a photo, the arrow points to the chase I want to eliminate.
Thanks as always

There are a number of engineering issues to address, the most important of which is adequate ventilation. Somewhere in the specifications for your refrigerator, you should find the number of square inches of ventilation required for a safe installation. I suspect that more will be required than just a supplementary fan. My suspicion is that you will find that you need a larger exterior ventilated grill and possibly a larger vent opening in the floor below the refrigerator. Based upon the number of threads that I have read about noise and other issues with those refrigerator ventilator fans in the more recent models, I don't know whether eliminating the ventilation chase would be a wise step.

My choice has been to stay with the original refrigerator exhaust ducting in both my '64 Overlander and my '78 Minuet. The operation of the refrigerator with the original venting method is totally silent, and my experience with small, high volume DC electric fans and the noise that they produce leads me to believe that an increase in noise level is likely. I do know that when the new Dometic 3-Way Refrigerator was installed in my '64 Overlander the size of the floor vent opening had to be increased slightly to meet the ventilation requirements of the new refrigerator. My '78 Argosy is still totally original in regard to refrigerator and venting.

Good luck with your project!

Kevin

[DryFly]

Originally Posted by CanoeStream

The fan ventilated fridges are noisy at night. Really? They're doing away with the natural draft fridge vents?

It looks that way. Neither of the 2 23' Overlanders we looked at had the chase, and both had a 12v fan on the exterior access panel. Near as I can tell they rely on the fan for ventilation.

[overlander64]

Greetings DryFly!

I am fairly certain that the refrigerator installation in your Argosy 20 is very similar (if not identical) to the installation in my Minuet 6.0 Metre. There is only one ventilated access panel on the exterior of my Minuet as can be seen in the photo below:



The Airstream Sport 22' in the photo below has two of the ventilation panels stacked with a refrigerator of approximately the same size as found in our Argosys. I suspect that the throught-the-floor vent opening is likely larger as well. I don't know whether the space between the iterior and exterior walls is utilized in any way for refrigerator ventilation . . . there was a time in some of the earlier Vintage Airstreams that the space between the inner and outer walls was utilized in refrigerator cooling.



Something else to consider is that the wall is likely discolored behind the fiberglass vent chase in your coach . . . and there will be the opening in the roof/ceiling to contend with as well.

Good luck with your project!

Kevin

[Gene]

Where do they route the wires to the roof for the antenna and solar panels?

Gene

[DryFly]

Thank you all for your most excellent responses. Looks like I'll be keeping the chase in place. Kevin, on reflection I think your observations are on target. I'm glad I asked this question before proceeding. Now I think I'll just paint the chase a neutral color and ignore it.

Dale

[TG Twinkie]

DryFly; I covered the plastic vent. Go to my blog for pics.

[DryFly]

TG - nice job on the remodel. It looks like you completely rebuilt the cabinets. What did you use for plywood? Did you stick with the 1/4" or go thicker?

[idroba]

I guess the problem solution is pretty well decided but here are my comments.

The original venting systems used, with the hole in the under floor and full roof vent system worked very very well. Quiet, and efficient.

Airstream then changed to no hole in the floor, and vent air provided by a perforated access cover in the side wall. Still worked pretty well, but in my opinion, not quite as well as the floor vent. It has less stack effect and more water penetration issues.

Then recently Airstream has gone with the common two side wall vents, one high, one low. Much poorer venting from these, no where near the stack effect that the old floor/roof system had.

Then, from what I understand they have been trying to fan vent the refrigerator, sometimes even having the outlet vent lower than the top of the refrigerator. (note: I have not used one of these, only read about them). The fans selected seem to be noisy and have generated a lot of complaints. They draw power constantly, so if boondocking, one more draw on the battery. The reports are also of poor refrigerator performance in hot weather.

So, not everything Airstream has done recently is a real improvement. For good refrigerator cooling, the largest stack possible is still best, and the fan systems could be made to work but don't seem to be well thought out, and still use more power.

BTW, in response to the original question, the fan cooling would be needed even when not operating on gas, as the heat from the refrigerator still needs to be removed, even when operating on electricity. It is not just the products of combustion which need to be removed.

A last response to another poster who stated that CO was produced by the refrigerator when operating. This is unlikely. Propane burns and produces CO2 and water vapor in most situations. Very little CO is produced, and that is the deadly gas. Only with incomplete combustion does propane burn and produce CO. It sure can happen, but not likely with a refrigerator, which has a very small flame and lots of combustion air available.

When you cook with an open flame gas range in your Airstream you do not get CO produced to any extent. Now, if you leave the burner on overnight, and have a very small trailer, you can use up enough Oxygen so the combustion process becomes incomplete and CO is produced. That is very deadly, as too many people over the years have found out (my cousin and his family all died from a CO accident, so I am paranoid about the subject). But burning propane itself usually is no problem as long as there is enough oxygen present.

[2vets]

This is an interesting thread! We have also been toying with this idea mainly because we have no roof vent/chimney since our original refrigerator was only electric. We are thinking of using a Norcold N300(29 3/4 inches high) or Dometic equivalent. Both are much smaller refrigerators and the side vent on our Airstream that is already there would be above the new refrigerator. The vent is roughly 8 inches in height and 12 inches wide and 31 inches from the bottom edge to the floor. We did wire the area with an extra 12 volt for a fan if needed. We already have a vent in the floor. See photos below. First two photos our of the old refrigerator that came out of the trailer. This would give us additional counter space and we would not have to cut a hole in the roof. What do you think?

[Wazbro]

2vets
I would much rather go with the 4 cu ft 37 3/8" high, then the 2.7 cu ft one you are looking at. Having the counter at 38" over top of the fridge and the vent is still a good height rather then a bit lower with a rise in the back to go over the vent. I think you would still be good since the top of vent would be about even with the top of the fridge, you probably should cut out the inner skin to open it up to the vent size though and seal between the skins, with either fridge.