Why does the fridge vent to the roof?

[Chopper]

Question: So why does the fridge vent up through to the roof? Why not just out the side panel like the hot water tank? In which case you could put a new fridge to vent out the side where the hot water tank was?

Thanks!

[scottanlily]

Hello chopper ,

probably vents to the roof because warm air rises .our 60 also vents to the roof as most do .I was thinking though that if you had a vent behind the fridge to the outside it could vent more trappped air and cooler could get in
as the fridge works better when cooler outside .

Scott of scottanlily

[47WeeWind]

Because they vent different things. Water heaters vent mostly combustion fumes from burned propane, and when "on" they burn much more propane for a given period of time than does a RV refrigerator when "on" and cooling. The highly heated air from a water heater creates its own draft so vents well thru a short horizontal exhaust pipe. RV refrigerators vent mostly passive air which cools the coils and is warmed up by heat transfer (as opposed to combustion), along with a little bit of combustion gasses if propane is the fuel and no combustion gasses when electricity is the fuel.

Since the fridge coil cooling air is typically passive (unless the owners had added a small fan or two to move the air along) and much cooler than water heater fumes, a greater chimney effect is needed for effective coil cooling. Venting through the roof with a longer chimney flue creates a stronger draft than venting through the trailer side, so a RV fridge cooled via a roof vent should be more effective and efficient than an RV fridge cooled thru a side wall vent which has a much shorter flue.

[Chopper]

It makes sense! Glad that I can shop around for a "fan operated" option as the vent cover is coming off!

Cheers!

[CanoeStream]

Chopper -- Fred seems to refer to a fan assist on coil cooling. Fred, does the roof vent also exhaust combustion products when operating the fridge on LP?

[Mike Lewis]

Chopper---If you remove the vent on the roof you must replace it with another somewhere and it has to be higher than the coils on the back of the frig. Bambis use a fan assited system where they have 2 louvred doors on the side of the trailer. On these air inters the lower and exits the upper with the assistance of a small 12 volt fan. Notice the trailers the factory uses this system in have small low refers that allowes the vents to be mounted in the flat side of the trailer. Air must circulate behind the frig and over the coils or it will NOT WORK. Closing off the roof vent and adding a fan to the existing door will not work as heat becomes trapped in the area behind the frig. For it to work you'll have to open a vent on the side of the trailer up higher than the coils of the frig. If this puts it in the curvature of the trailer body this will be difficult to build plus seal out water. I suspect this is the reason for factory vents being on the roof in the first place.----- Pieman

[Chopper]

Hi,

Thanks for the tips.

Because I'm doing away with the bathroom in the back of the Argy26, I'm moving the hot water tank forward and using the old fridge panel for access to the hot water tank. This will put the hot water right in the cabinet where the sink will be.

The fridge will be a smaller one (as you mentioned) that I want to cut into (yikes!) the side next to the hot water tank...finally, I'll use the old vent location as the new cooktop vent and cover up the old cooktop vent on the curbside of the Argy.

Anyways, that's what I'm currently shooting for!

Cheers!

[bake315]

Originally Posted by Chopper

Hi,

Thanks for the tips.

Because I'm doing away with the bathroom in the back of the Argy26, I'm moving the hot water tank forward and using the old fridge panel for access to the hot water tank. This will put the hot water right in the cabinet where the sink will be.

The fridge will be a smaller one (as you mentioned) that I want to cut into (yikes!) the side next to the hot water tank...finally, I'll use the old vent location as the new cooktop vent and cover up the old cooktop vent on the curbside of the Argy.

Anyways, that's what I'm currently shooting for!

Cheers!

Be sure and shoots some pics of your progress - we'd like to see 'em!

[Chopper]

Hi Dave,

I've posted pics of the project under "Shall we get started".

Hopefully there'll be more there by the end of the weekend if I get the Argy under shelter to take the AC and roof vents off, the back light bar off, one wheel off to take a look at the suspension, the black and grey tanks out, the water tank out, the hot water heater off, the copper pipe out, the clouded wing window out, the inside old fridge chimney cover off...

hmmmm...my mind space is obviously at the Argy and not at the office!

Cheers!

[47WeeWind]

Originally Posted by Canoe stream

Chopper -- Fred seems to refer to a fan assist on coil cooling. Fred, does the roof vent also exhaust combustion products when operating the fridge on LP?

Hi Bob:

I'm not familiar with any trailer built after 1970, so can't say for sure, but I suspect they do. My 1964 19' Globe Trotter fridge has the propane heater chimney on the rear of the fridge. It vents just below the top of the fridge body, where those the combustion fumes join with cooling coil warm air on the upward journey to the trailer roof vent. Even the late 50's/early 60's Ohio built trailers that, up through 1962, vented the cooling coil warm air into the trailer living space behind the fridge shelf had a separate smaller chimney and roof vent just for the propane combustion products, which vented outdoors. Hope this answers your question Bob.

[scottanlily]

Water heaters produce alot of HOT exhaust air and therefore need to be expelled quickly out the short exhaust shroud ,and the heat rises upward out the shroud as the original shrouds did. secondly the warm fridge air does rise
up into the vent out at the roof , it would be difficult to vent it straight out the side unless an exhaust fan is there to evacuate the combustion on LP
to the out side ,so as simple as my answer was hot air still rises .the vent
on my ohio tradewind just captures some of the air to the roof ,so i feel the
warm air rising up from the rear of the fridge .It is not HOT air as you have with the water heater.the furnace also vents to the roof ,hot air rises up to the roof ,no exhaust fan is necessary.

Scott

[dejahardy13]

Do I have to vent the air from the fridge? Assuming I'm not using propane for fuel, can't I just use it to heat the interior of the trailer? (The heater doesn't work.)

A previous owner closed over the roof vent and removed the piping for propane. If I want to go back to propane, is it best to run new lines to the front, or could I do something quick and dirty, like putting a small propane tank next to the fridge?

Thanks.
Dejah

[overlander64]

Greetings Dejah!

Welcome to the Forums and the world of Vintage Overlander ownership!

Originally Posted by dejahardy13

Do I have to vent the air from the fridge? Assuming I'm not using propane for fuel, can't I just use it to heat the interior of the trailer? (The heater doesn't work.)

The RV Absorbtion Refrigerator (Dometic, Norcold, etc.) requires cooling air to keep the unit from getting to hot and loosing efficiency. The electric element on the refrigerator produces far less excess heat than when the unit is run on LP, so likely wouldn't produce significant heat gains in an interior the size of an Overlander.

Originally Posted by dejahardy13

A previous owner closed over the roof vent and removed the piping for propane. If I want to go back to propane, is it best to run new lines to the front, or could I do something quick and dirty, like putting a small propane tank next to the fridge?

Should you decide to go back to using LP with your refrigerator, you will want to insure that you have proper vetilation both for your safety as well as for the efficiency of the refrigerator. The '64 Overlander had through the roof as well as through the floor ventilation. Among the frist things that I would suggest checking is the fiberglass/ABS flue that runs along the exterior wall, through the cabinet to the roof vent - - if it isn't sound (free of cracks and well attached to wall), it should be repaired or replaced. The parts to repair your roof vent should be available through almost any Airstream dealer or Authorized Airstream Service Center. The floor vent is simple a suqare cut in the floor behind the refrigerator that has screening to keep insects/rodents out, and allows for a chimney effect to keep the gasses moving insuring the efficiency of your refrigerator's cooling system.

Unless the previous owner did an entire system replumb, it shouldn't be too difficult to reconnect the LP supply to the refrigerator. Prior to proceeding with this reconnect, you might want to have a trained technician inspect the refrigerator to be sure that there wasn't a defect or malfunction that caused the LP to be disconnected in the first place. Barring a malfunction or defect, there will likely just be a plug in the line where the refrigerator supply was attached -- removing that plug and installing a new supply line should would be the direct approach. If you aren't familiar with LP system plumbing it would be advisable to have an experienced technician handle the reconnect.

Good luck with your Overlander!

Kevin

P.S.: It isn't a terribly difficult process to replace the original furnace with a modern RV furnace. The advantage of the new furnace would not only be safety, but they have electronic ignition so that it isn't necessary to light a pilot when you are ready to use the furnace.

[lewster]

All manufacturers of RV style refrigerators (ammonia/hydrogen gas absorption fridges) require specific baffle designs at the rear of these units to properly vent heat produced by the heating source (LP or electric element) and to provide a natural path of convected air moving over the condenser coils at the top of these units.

It is when the this natural convection is either blocked or not working properly (extreme ambient temperatures) that the performance of these units will degrade and be less than satisfactory ( interior fridge temps above 42*F).

This can be remedied by adding computer style fans just below the condenser coils (as some of these OEMs do), adding a fan at the bottom of the unit on the floor blowing upward, or adding exhaust fan(s) at the top vent of the unit. I have had success with all 3 modes of auxiliary venting.

The important thing to remember is that every RV fridge has specific requirements as to the shape and size of the rear baffle, which can be found in the units installation manual. Deviating from this plan will almost always result in degraded performance of the fridge.

[easyride]

My 63 vents thru roof,however I was at a TCT outing,2 other 63 GTs there,and both of them vented thru side wall,1 was Ohio built,1 was Ca,mine is Oh.,don`t figure. Dave

[dejahardy13]

Thanks, Kevin, Lew, for the information and the welcome.

The fridge I just got is out of an 70-something Argosy. When the previous owner covered over the roof vent, s/he also removed the LP pipes. :-(

The fiberglass flue looks to be in good condition, it just doesn't have a roof vent anymore. Does the fridge fit completely under it, or just the coils?

The hole in the floor is still there, too. It actually seems to be two holes, one large rectangular one and a smaller square one. Are there suppose to be two? And there are two small strips of wood to either side, just where the bottom braces of the fridge are. Is this normal, or did the previous owner likely add them. Then don't look very original.

Is there anywhere on the fridge that tells what the make and model are? I didn't see any kind of identification plate.

There are Airstream Service Centers? Wow! I guess I thought they were all gone. But now that I know to look, there is one not far from here. Thanks!

dejah

[moparjohn]

since we are on the subject, my tradewind's PO installed a new fridge, and it seems at the same time put an alumium air vent/grate on the outside of the fridge access door, I know it's not original. Did the original door have any holes? (1973 Tradewind) I would like to replace it with a correct door wilthout the vent. MPJ

BTW anyone with a fridge door let me know.