Fridge ventilation on new Dometic

GeekSquadOfUn · 07-24-2019, 03:22 PM

Trying to improve performance on my Dometic RM1350, in my Cougar 315RLS. I installed these 3 computer fans at the top vent, pushing air out. Ran the power wire down to the 12V block connector. Also installed a thermistor, so that the fans power up only when it reaches 110F.

Having a hard time in having it show less than 40F... Hovers around 42 to 46, not pleased with that. I've also installed thermometers inside both fridge and freezer to see how acurate those numbers are...

I'll also check all my door seals. Next step air flow inside the fridge. One kinda wonders why Dometic puts out a fridge like that... Many have similar issues.

On my older 5th wheel, with a 2 door Dometic, was always between 35 to 38F... Miss it.

Customer1 · 07-24-2019, 05:09 PM

The refrigerator is probably fine. From the picture it is obvious that it is not installed as best as can be. Refrigerators in slides can be a problem. Your upper vent is too low for proper convection flow.

Blame the RV designer, builder, not the refrigerator.

bobbecky · 07-24-2019, 05:42 PM

The baffle in the photo is exactly where it should be, so air fully passes the fins. If that baffle was not there or lower, you would not get adequate heat removal at the upper fins. There are a number of issues that can cause insufficient cooling in the fridge, and your manual should have diagnostics that you can follow, or maybe it is better to just get a qualified tech to check it out.

**chuckster57** · 07-24-2019, 06:39 PM

Fans should be installed UNDER the coil assembly. There should already be fans installed if the refer is on a slide, are they not working?

As stated that baffle is right where it needs to be. And the upper vent is installed in the correct position.

GeekSquadOfUn · 07-25-2019, 04:21 AM

Yes, there are fans installed at the factory and they do work, as you can hear them kick in & out.

I added the top ones to help exhaust the warm air after the top coil.

**chuckster57** · 07-25-2019, 06:50 AM

I don’t think your issue is the air circulation. Have you looked real close at the center flap on the door, and the door seals.

GeekSquadOfUn · 07-25-2019, 10:27 AM

Quote:

Originally Posted by chuckster57

I don’t think your issue is the air circulation. Have you looked real close at the center flap on the door, and the door seals.

Yep, but I'm not sure what to make of it... Not sure hiw to check it's leak proof or not... I'll look again, with a dollar bill, well a $5 bill, as it's the smallest paper currency we have... 😁

MerlinB · 07-25-2019, 12:20 PM

Quote:

Originally Posted by GeekSquadOfUn

Yep, but I'm not sure what to make of it... Not sure hiw to check it's leak proof or not... I'll look again, with a dollar bill, well a $5 bill, as it's the smallest paper currency we have... 😁

You probably should use two $5 bills because I don't think that slick plastic currency you guys have is as thick as our $1 bills.

7Iron · 08-29-2019, 02:13 PM

Here are 3 slides from a briefing by ? when ? to whom ?
In the Diagnostic Service Manual it refers to an Application guide 3308666, and this is what I found that briefing

Refer to your manual for the dimensions for A thru F

The "wide open" condition is during a test and notice that too much space can cause not cooling.....don't remove any wood, unless a Dometic engineer recommends it.

7Iron · 08-29-2019, 02:35 PM

I should have started at the beginning.....We owners must ensure:

a. that we are level

b. that we have not altered the as built/as designed ventilation...dirty,wasps nest etc. (assuming that the as built matches the as designed...there is a youtube video showing the upper vent being totally closed...they never cut out the opening)....If the unit some times cools and sometimes doesn't then the as built venting is probably as designed....the design may suck ??

c. and that we are providing energy to allow for the heater to work...elec, or propane.

d. Ambient temp is below 100 (I haven't figured out how to control this one) and I wonder if they really mean the "ambient" temp of the air channel not the ambient temp of the location ??? and if they are really meaning the air temp of the air channel , then shading will work....I have not yet experience ambient temps of 100.....we are generally 85-90 with 99% humidity.

But I am sure that the air channel has exceeded 100...your thoughts

travelin texans · 07-25-2019, 07:26 AM

Adding the $10 2-D cell battery operated fridge fan to the back of the bottom shelf helps as much as anything else from my experience.

7Iron · 08-29-2019, 01:28 PM

GeekSquadofUn,

I also have the 315RLS with the same refrig condition and our previous TT refrig worked great.....39 is the coldest mine has ever gotten...and I would be ok with that, but in the hot south 46-54 is the norm and that dog don't hunt.

I am going out tomorrow to look for fans, and if they are there then I think that is my problem they are not running....

Make sure the make up strip between your doors closes....we have to manually close it and several other 315RLS ers have had the same issue, I don't recall who fixed theirs by adding a few washers on the bottom hinge to lift the door so that the make strip rides in the opening and closure bracket mounted between the top of doors .

I just order exhaust fans, do I need to canx the order or are yours helping? I am also adding a interior recirculating fan.

Laredo Tugger · 08-29-2019, 01:49 PM

I had cooling issues with my Norcold fridge on a recent trip. The fridge side of the trailer was in the hot afternoon sun every day but the prevailing winds (daily) blew on that side of the trailer as well.
I removed the small plastic tabs that hold the the fridge covers on and replaced them with zip ties creating a hinge effect and the propped the covers out away from the trailer with short sticks (as I was parked for 3 weeks). They were able to deflect any rain that might have occurred.
Dramatic difference in cooling. I actually had to turn the fridge to a setting that did not freeze items in the fridge area.
It's almost worth a look at having powered louvers for fridge vents available on future campers,at least I think so.
RMc

GeekSquadOfUn · 09-15-2019, 01:10 PM

For peace of mind I installed on the outside, to the right of the fridge, this thermometer from Acurite.

There are 2 sensors: 1 in the fridge, 1 in the freezer section.

My fans do the job well.

jsb5717 · 09-05-2019, 05:48 AM

This is a very common issue with the larger double wide fridges in slides. The OEM fans do kick on but when the slide is in direct sunlight with 80 degree temps and higher the fridge just can't keep up. The small space around the fridge gets quite warm and the OEM fans just don't move enough air up and out.

I also installed a couple larger fans with a programmable thermostat (similar location as the OP). So far it seems to have done the job. The application seems to pull more air up through the cooling fins and out the vent. Fridge normally runs at 34/35 degrees and peaks out at about 39. Before it would get to high 40's in the afternoon sun.

I've wondered if a slide topper would help by keeping sun from cooking the roof above the fridge...

jsb5717 · 09-05-2019, 09:29 AM

^^^ Yep, same here. Bottom line is that the OEM setup is inadequate. I don't know if the baffles are too far away from the fins or there's too much space at the top of the fridge. The design isn't working and all I know is that there's just too much heat build up in the box and not enough air flow to get it out. The extra fans seem to solve the problem.

jsb5717 · 09-07-2019, 11:58 AM

This kit is similar to the one I used. Mine came with a programmable thermostat but I don't see that kit right now

https://www.ebay.com/itm/DOMETIC-NOR...kAAOSwi7BdI17s

7Iron · 09-07-2019, 01:08 PM

Quote:

Originally Posted by jsb5717

This kit is similar to the one I used. Mine came with a programmable thermostat but I don't see that kit right now

https://www.ebay.com/itm/DOMETIC-NOR...kAAOSwi7BdI17s

Thanks

I opted for building my own kit...
a. Inside circulation
https://www.amazon.com/Deluxe-RV-Ref.../dp/B0725HQ9BN $32

b. thermistor/thermocoupler $8
https://www.ebay.com/itm/Dometic-Fan...item2a3efa157c

c. 140mm 155cfm IP67 waterproof fans 4ea $18
https://www.amazon.com/dp/B07NYQ357N...NsaWNrPXRydWU=

d. Aluminium tape and foil wrapped insulation board.

Glad you all cleared the path....I am now all in!!

I may leave the doors open and use my upgraded refrig as 3rd AC....

gearhead · 09-07-2019, 02:12 PM

You can also use "external" snap rings on that door pin. I don't recall removing my door to install them. Probably just needle nose pliers. The door has to be lifted enough that it easily follows the bottom track for the center flap.

GeekSquadOfUn · 09-08-2019, 02:32 PM

Not exactly sure what you mean... Snap rings slid on the bottom hinge of the left bottom fridge door to lift the door just enough?

I also thought of removing the plastic channel at the top in the middle to maybe lower it instead...

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