Refridgerator cooling cure

[Lgray12845]

My background is engineering and this may help both technicians and installers of refrigerators in slide outs that have poor cooling ventilation. I was asked by a tech to find a better way especially for the double door refrigerators!. This may be known to some but not by all of the most important guys. No refrigerator can cool properly unless the airflow is a great enough to remove the heated air trapped in The chamber in the rear. Most everyone knows this.
We purchased a new 2016 fifth wheel with the refrigerator in a slide out . This means that both the cold air inlet and outlet are on the same wall of course. With that being said the airflow is not as good as roof chimney styles because it is a very low and short chamber which naturally restricts airflow . (The taller the chimney the more natural draft ) Our refrigerator as most installed in slideouts had an electric fan on the rear in the center in order to assist draft . The fan was operating properly turning on and off depending on the temperature of the chamber . When the outdoor ambient temperature was above 60°F the fan would never shut off meaning the refrigerator was burning propane or on electric and running constantly . Our refrigerator on a hot day would not cool below 60°F with an outside temperature of 85°F in the shade . The freezer would hover around 35°F .
I have seen many suggested cures online by adding up to four or five fans in the bank all across the rear ventilation area thus forcing the hot air to rise and exit the chamber when the fans are on . This is the same as installing a baffle utilizing one or maximum of two fans. ( the width of four to six fans creates the same effect as stopping the circular air motion with the baffle and using one fan..
The solution we I'll provide below should allow your refrigerator to cool very very well with only one fan . It also will not drain your battery power as it will if you add 2, 3, or four more fans as some suggest. The addition of extra fans should not be needed.
First we made sure the refrigerator was properly insulated left and right to the walls with the fiberglass insulation . Then we guided the airflow that ended up at the top of the refrigerator so it more easily exited the air vent by installing an aluminum faced 1/4" thick insulation material cut to fit and curved to the top section air vent. We have fixed it to the chamber using aluminum faced furnace tape . The second and most important was to build and air baffle that completely surrounded the single fan and had only the fan area as an opening through the baffle. The baffle was constructed using two pieces of material so that it could easily overlap each other to surround the fan . when they were installed the pieces were overlapped and screwed together. This was done so that the air that the fan moves does not go in a circular motion on the left side of the fan and the right side of the fan in the air ventilation chamber causing basically little to no air to be blown vertically Just think of a very small window fan in your house sitting in the middle of the wide window without the left and right side of the window opening blocked . Air will not be removed from the room . This is why a baffle must be used to remove hot air in the chamber . Now with just one fan we have a strong blast of hot air exiting the upper vent when the fan is on.
I think that because in the past electric fans were not needed to assist ventilation when RVs had roof chimney vents this may be the reason that some installation instructions for refrigerators do not include the idea I have just mentioned using an air baffle . Now with the refrigerators being installed in slide outs and a very small low air ventilation chamber being used, an assist fan is needed .
Now on a hot day with the outside air ambient temperature at 85° F the lower refrigerator portion will cool down to 35° F And the freezer Section will be at about 0° F. My single refrigerator fan only goes on about half the time and sometimes not at all for long periods which is fine because the refrigerator is ice ice cold and our batteries stay charged. Hopefully this helps everyone.

[Mustang65]

Thanks for the information, I am sure a lot of members will be interested in this solution. If at all possible can you include a few pictures that will help anyone that will duplicate your fix.

Don

[Marcm157]

X2 on the picture request. I understand what you are describing but pictures always help me visualize...

[norty1]

My rig has the factory fan that hardly ever runs. I installed another that also hardly ever runs. My fridge does a great job of cooling no matter what the outside temps are even in open sun w/ no shade.

I would think that unless you have a problem this solution may be overkill.

[bansai]

Yep, pics would be cool. This is pretty far down on my wish list, but it's still on there somewhere, just to squeeze out more efficiency. What model is your fridge? Norcold? It actually sounds broken to me if your freezer won't go below 35F in 'normal' conditions here on earth.

[oldmanAZ]

Thanks for the information and welcome to the forum.

[Lgray12845]

Hi
It is a very simple solution to a prevalent problem with some installations. Our Fifth wheel is a brand new 27.5 eagle ht. It basically would not cool unless it was cold at night. Now it gets too cold

How do I add photos to this?

[Lgray12845]

Hi Yes it is a Norcold 8cu ft. How do I attach photos to this thread?

[Marcm157]

Originally Posted by Lgray12845

Hi Yes it is a Norcold 8cu ft. How do I attach photos to this thread?

Click on "Go Advanced" at the bottom of the post and then scroll down just a bit more and you will see "Manage Attachments" you can upload pics from there.

[Lgray12845]

With the baffle added it dropped to 10 degrees below zero in the freezer and about 35 degrees in the lower fridge section. It now runs 1/2 of the time.

[Lgray12845]

see photos - sorry the baffle is a sketch it is behind plywood and placed around the fan.

[bansai]

Nice work BTW. Just out of curiosity, did you contact your dealer about the fridge not working right before you did this 'mod'?

Kind of curious if they told you to just live with a fridge / freezer that couldn't make ice or keep food from rotting, or if you brought it to their attention. A freezer that doesn't make ice is a defect.

[Lgray12845]

For photos go to this dropbox link

https://www.dropbox.com/sh/dhqs86pkd..._gbWeyuya?dl=0

[Lgray12845]

The dealer did not not know the answer but I was kind and 100 miles away and told them I would let them know the cure. The solution was not in Norcolds installation instructions. The dealer said any expense would be covered by Jayco. I am happy to help everyone.
See photos at link For photos go to this dropbox link
https://www.dropbox.com/sh/dhqs86pkd..._gbWeyuya?dl=0

[bethcb]

Samsung told our dealer on our household refer that it was not vented properly. We could not keep it cold. They remounted the refer so as to no block the vents and also added a fan that turns on when temp is high. That and an 1800 pure sine wave invertor has solved our problem, the latter being the better solution. Still think the extra fan has helped.

[JEFF1963]

Lgray... -HMM, I admire your altruism in helping Forum members, but might it behoove you to think "patent"? Yes, perhaps you'd experienced a problem not normally associated with you RV, and heaven forbid it should raise prices, but you've apparently invested considerable time and effort to correct what may be a systemic issue. Even if "patent" were a consideration, any resulting contract might be written to ameliorate any price increase you wish to avoid. Good effort and deeds should be rewarded, and it seems you may have performed both. Additionally, the boating industry might be very interested in your idea/solution.

[twoballscrewball]

I take it that for those of us with a standard wall installation and a roof vent, this is much less of a necessity?

[Lgray12845]

Here are the photos. The baffle sketch is all I have right now. I cannot get a photo of it without taking off the shield.

[Lgray12845]

Yes with a roof vent a fan is normally never needed because of better ventilation due to better height = a faster air rise.

[Lgray12845]

I currently hold four US patents for RV kayak racks. I thought about that for this but now this is general knowledge and it was fairly simple to fiquire out. I felt that I should help everyone that needs this info. It will be a short while and the refrigerator manufacturers will include this in the installation instructions.