vent under refrigerator

[dnrtheil]

Hello all,
We just brought home a '64 Trade Wind about 8 hours ago (our first AS - yeah!!!)

As we were cleaning, we noticed a screened opening under the refrigerator (Dometic) - is this normal? It seems to be letting in a lot of cold air (and man was it cold in Michigan today!)

Anyone else come across this?

[clancy_boy]

A lot of the older units have these - my '66 Caravel does - usually the fridge area ducts up through the roof vent and does not allow the air from back there to enter the trailer. There would be combustion gases in that area and that hole is to allow freah air to enter to keep the flame going and all of it vent up through the roof. If you are not using the fridge on propane you may be able to block that vent but if it has an auto switch to gas - if you lose power then there could be a problem.

Congrats on the new trailer and good luck. Welcome to the forums.

Mike

[Zeppelinium]

DO NOT BLOCK THAT VENT.

Amonia based refrigerators require a chimney behind them to create a vertical cooling airflow that is essential to the condensation phase. If you block that vent and the air in the space behind the fridge gets warm and stagnant, the fridge will stop working. It may also damage the fridge in the same way that being off level does--by depriving the evaporation area of fluid and crystallizing the slkheltslck stuff, which cannot be fixed. period. This is true whether you are operating on propane or electric.

Second point: the chimney should be sealed so that no air from it can enter the inside of the Airstream. It is its own vertical channel of air, isolated from the rest of the interior. Air goes in the bottom vent and out the rain-protected top vent. Both must be open, all the time. If you're concerned about the cold, you can add insulation to the walls of the chimney.

Zep

[flyfshr]

I'll second what Zep says. That vent is an integral part of the fridge's operation and needs to be kep clear and unobstructed at all times. My trailer has two 5" diameter holes under the fridge. When I was redoing the interior, I replaced the small window-type screening material with a much stronger mesh. This new mesh is the kind with a diamond pattern and came off my old air filters from my truck.

Brad
FF

[Mike Lewis]

Originally Posted by dnrtheil

Hello all,
We just brought home a '64 Trade Wind about 8 hours ago (our first AS - yeah!!!)

As we were cleaning, we noticed a screened opening under the refrigerator (Dometic) - is this normal? It seems to be letting in a lot of cold air (and man was it cold in Michigan today!)

Anyone else come across this?

This type of refrig. requires air flow up across the fins on the rear of the unit to work, as well as to provide air and exhaust to the burner when using it on propane. Notice new trailers have louverd doors on the sides behind the refridg. These doors do the same thing as you floor opening. One thing you style offers is that it would be less likely to have the burner blown out by passing vehicle. Newer will go out sometimes from the buffeting wind as you are passed by other vehicles------pieman

[Zeppelinium]

Originally Posted by Mike Lewis

...One thing you style offers is that it would be less likely to have the burner blown out by passing vehicle. Newer will go out sometimes from the buffeting wind as you are passed by other vehicles------pieman

I made a small baffle box out of 0.025 aluminum sheet, bent using a vise and 2x4. My old Dometic had one that was obviously hand made and it never blew out. The new Dometic blew out if I thought about it. However, the new baffle worked perfectly--it has never blown out since I installed it. So if you're having trouble keeping the fridge lit while driving, try a baffle before you give up.

Zep

[dnrtheil]

Thanks for the info, well keep the vent open. Being our first AS I am sure we'll have many questions like this. We did get a manual, but the information in it is pretty limited.

Derek

[PoconoAir]

The fridge in my '65 Caravel was sitting on 3 2x4s. I guess these were to provide spacing up from the floor for air flow. I am in the process of a complete rebuild. I could replace the fridge on these or new 2x4s or some aluminum c-channel I have but not sure how these function. Any ideas?

[Zeppelinium]

The fridge does not have to be up off the floor for air circulation, unless the hole in the floor is underneath. Usually, the vent hole (about 4" x 10") in the floor is adjacent to the shell/wall, which allows air flow up past the back of the fridge. In 70s AS, the air continued up through a plastic flue above the fridge to a covered exit hole near the top of the shell. In the 60s Bambis, the air was vented through louvers in the shell right at the top of the fridge. I think the longer flue provided for a better chimney effect and better air flow.

The only reason I ca think of for the 2x4s is some kind of structural reinforcement across the floor or to make it more convenient to get at stuff in the fridge, like bring it up to just under the cabinet height. Otherwise, they are not required.

Zep

[PoconoAir]

Thanks. I would like to get the refrigerator up high but it is best to keep anything heavy low if possible in addition to the convection issue. I intend to put the AC on the floor too.

[59toaster]

Here is some good reading on these type of reefers.

http://gasrefrigeration.net/dom_techdata/MAN_SM.PDF

It is critical that the cabinet around the reefer be air tight to the interior of the coach. failure to do so could allow CO to gather in the coach. If this coach has been sitting I would recommend completely checking the flue and the cabinetry and going through some general checks that will be outlined in that link.

Congrats on the new (to you) coach!