Fridge ventilation on new Dometic

[GeekSquadOfUn]

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]

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]

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]

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]

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]

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.

[travelin texans]

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.

[GeekSquadOfUn]

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]

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. :hide:

:lol:

[7Iron]

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]

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

[7Iron]

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]

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

[Tooth Ferry]

I also filled the big heat holding void over the whole top of the frig with insulation and placed a baffle made with aluminum sheet as close to shape and dimensions shown in installation instructions as I could to move air out of top vent. Mine came from factory with 4 fans but no baffle or top insulation. Fans should blow from below fins. Mine stays at 34 and freezer freezes everything but ice cream is not very hard.

[GeekSquadOfUn]

Very happy to report that adding my 3 computer fans at the top did work.

Warm air exits the top more easily.

I do need to close the left door flap manually, as the weight seems to tilt the door just enough that the flap misses the channel at the top and will not fold as it should. Ah well, I can live with that.

It stays in the 33 to 38 range , depending on the settings.

Happy camper ⛺

[jsb5717]

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...:ermm:

[chuckster57]

Very happy to report that adding my 3 computer fans at the top did work.



Warm air exits the top more easily.



I do need to close the left door flap manually, as the weight seems to tilt the door just enough that the flap misses the channel at the top and will not fold as it should. Ah well, I can live with that.



It stays in the 33 to 38 range , depending on the settings.



Happy camper [emoji554]



Easy fix: remove the freezer door to access the fridge door upper hinge. Lift off the door and put a washer on the hinge pin, Re assemble. I do it a lot to brand new fridges.

[7Iron]

Very happy to report that adding my 3 computer fans at the top did work.

Warm air exits the top more easily.

I do need to close the left door flap manually, as the weight seems to tilt the door just enough that the flap misses the channel at the top and will not fold as it should. Ah well, I can live with that.

It stays in the 33 to 38 range , depending on the settings.

Happy camper ⛺

Geek,

Did the 4 factory installed fans work? and I think that I recall that you did not have the eighth inch aluminum foil baffle at the top ??

in our pics you can see a gap between the bottom of the condenser vanes and the top of the "box baffle" the protruding luan and it appears to me that (some or most??) of the air from the 4 factory fans would go through that gap (least resistance)

All of the dimensions on my 315RLS conform to the requirements except "C" I only have 4 inches (+- 1/4)

[GeekSquadOfUn]

The 4 factory fans do work, as I can hear them when they start. My 3 additional fans at the top help in moving the hot air over the fins.

I'm happy, it lives up to the name Refrigerator. ��

I'm done.

[jsb5717]

^^^ 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.

[GeekSquadOfUn]

Easy fix: remove the freezer door to access the fridge door upper hinge. Lift off the door and put a washer on the hinge pin, Re assemble. I do it a lot to brand new fridges.
Thanks for that tip. Will do.

Much appreciated.

[Laredo Tugger]

Yes. Thanks chuckster.
I have the same problem and have been looking for a solution.
RMc

[7Iron]

Could you provide parts lists (fans and thermistor) where and how much?

are they 140mm or smaller

thanks


I am adding fans next week, just don't know where I will get them or what size, or how many. And I am having a heck of a time finding a thermistor normally open to close somewhere between 85-120, preferably closer to 85

[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-NORCOLD-Refrigerator-Fan-ON-OFF-Thermostat-Wiring-SMFK2C-ships-TODAY/123828896613?hash=item1cd4c70365:g:q9kAAOSwi7BdI17 s

[7Iron]

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-NORCOLD-Refrigerator-Fan-ON-OFF-Thermostat-Wiring-SMFK2C-ships-TODAY/123828896613?hash=item1cd4c70365:g:q9kAAOSwi7BdI17 s

Thanks

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

b. thermistor/thermocoupler $8
https://www.ebay.com/itm/Dometic-Fan-switch-for-add-on-condenser-fans-85D-closes-at-around-85-F-degree-/181445203324?hash=item2a3efa157c

c. 140mm 155cfm IP67 waterproof fans 4ea $18
https://www.amazon.com/dp/B07NYQ357N/ref=sspa_dk_detail_6?psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE1MkYzSTA1NVdXWTImZ W5jcnlwdGVkSWQ9QTA5MzY4MjAzUzJPMFhRVTdSVkQ3JmVuY3J 5cHRlZEFkSWQ9QTAzNzg1MDQzN1BXOUM0SlEyMTFKJndpZGdld E5hbWU9c3BfZGV0YWlsMiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZ kb05vdExvZ0NsaWNrPXRydWU=

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]

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]

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...

[chuckster57]

Snap rings or E clips? I use a washer because it can’t fall out.

[7Iron]

Symptom(s) reported: Freezer works but refrig climbs from 38ish to 50+ish

5 Issues Reported and the fixes implemented:

1. Center seal on the left hand door does not work, does not follow track. Raise the door by adding washers.

2. Lack of internal air flow/circulation: add internal fan added and wire to the light.

3. Improper external airflow over condenser: add additional fans above the condenser pulling the air to augment the 4 existing vent fans at are below the condenser pushing the air.

4a. Heat build up in the top of the fridge compartment: add insulation/insulation board and smooth seams using aluminium tape.

4b. Turbulent air flow and heat build up in top because of missing turning vane baffle. add curved turning vane baffle when performing 4a.

5. Door latch improperly adjusted (see video) : adjust latch. https://youtu.be/PWiaRU311L4

[GeekSquadOfUn]

Thanks for this recap, that should do it.

[concours]

check on line look for The Cooling Wearhouse rvcoolingunit.com I used their products to vastly improve the performance of our Dometic fridge.
when you find their site kook under performance parts, we installed extra evaporator fans, a condenser fan, a fan to push hot air out of the upper vent and a lower set point thermistor to turn the fans on sooner

[sully585]

ok i'm weighing in here because i have a Cougar 368MBI with the Dometic RM1350 and i'm having the EXACT same problem. it's been very hot here in TX and my fridge is basically exposed to the southern sun all day. i bought 2 of these https://www.amazon.com/AeroCool-Silent-Master-200mm-Blue/dp/B009XERK6G and i found a couple good videos on youtube about how to install them on the top vent. the only thing i'm unsure of is how exactly do i wire them into the 12v power?

should i tap them into the power wires for the existing fans so they all turn on at the same time? and how exactly do i do this?

[GeekSquadOfUn]

Look at the bottom rear of the fridge, you'll see a white plastic block connector. Just connect there and Bob's your uncle.

Easy peasy.

[jsb5717]

In mine, inside the bottom vent, there is a wire block with available 12v. I just fished the wires down the side of the box, being careful to keep them away from the hot parts of the fridge. Use a multi-meter to find your positive and negative poles and attach there.

Also, unless you really know what your doing for using the components you need to make this work I would search for a kit that includes the fan(s), mounting hardware, thermostat(s), and possibly a fuse with an on/off switch (mine came with that). Kits are available on ebay.

[7Iron]

should i tap them into the power wires for the existing fans so they all turn on at the same time? and how exactly do i do this?[/QUOTE]

sully585,

It depends:
1. do you want them to run all the time or only after a certain temp is reached where the fans are located.
2. do you only want them to operate when the refrig is turned on.

1. I installed 4 additional fans, 2 will come on at 30c (86ishF), and the next 2 will turn on at 50c (122F)

2. mine will operate even if the refrig is not turned on.....We always have the refriq on (essentially all the time--) when the battery is on....with very short minor exceptions....and this wiring is much easier


here is the 30c https://www.ebay.com/itm/Dometic-Fan-switch-for-add-on-condenser-fans-85D-closes-at-around-85-F-degree/181445203324?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

but now have found on amazon (45c to 90c --113-194F)
https://www.amazon.com/uxcell-Normally-Temperature-Thermal-Thermostat/dp/B07PFV6YTQ/ref=pd_cp_60_4?pd_rd_w=gYosm&pf_rd_p=ef4dc990-a9ca-4945-ae0b-f8d549198ed6&pf_rd_r=0Z4JNQCB21Z1NQT04F3Z&pd_rd_r=e13dfc49-40cf-487a-8bfb-364776cf2b06&pd_rd_wg=H9Mdp&pd_rd_i=B07PFV6YTQ&psc=1&refRID=0Z4JNQCB21Z1NQT04F3Z

These are normally open bimetal disc thermostats that when they reach the rated temp they close and complete the circuit. They are rated at 2amp, and my fans (140mm super high CFM) draw .7 so 3 wired in parallel would be pushing the rating..

I wired the themostats in the grd leg of my fans so when temp is hit they turn on.

at the bottom of the refrig (lower vent cover removed) there is a wiring block with 12v , always on when battery switch is on. I used it.

If you need pics and or wiring diagram , send me a msg.

dg

PS : there are 4 other issues that others have fixed with this refrig, see the link above in my post...

[7Iron]

I will probably add a switch so that just incase there is a time when we would have the battery on for an extended time without having the refrig on, I can kill the power to the fans...Thanks jsb5717

[7Iron]

Also, unless you really know what your doing for using the components you need to make this work I would search for a kit that includes the fan(s), mounting hardware, thermostat(s), and possibly a fuse with an on/off switch (mine came with that). Kits are available on ebay.[/QUOTE]

coolerguys in seattle may be a very useful source , they spent a half an hour critiquing my design. (although GeekSquadOfUn is correct : easy peesy) I am just anal ...

but they have a really cool thermostat (programmable temps) with display that installs inside the 5er so that you know what the status of the fans ...I think it was around $15....unfortunately it would not handle my 2.8 combined amps.

https://www.coolerguys.com/collections/thermal-monitors


notice your fan has a 3 pin to 4 pin adapter, they also have connectors (less than $2) that makes for a professional looking installation that is easier than soldering, crimping, or using wire nuts.

[jsb5717]

My kit came with this programable thermostat. I can set the min/max for fan operation and also see the current temp. It's in Celsius only but once you do the conversion to F it's easy to set up.

I've set mine to turn on at 46C (~114F) which is about when the OEM fans kick on. It's set to turn off at 41C. I've got the Thermostat probe tucked into the top of the box where it's the hottest. I'm still fine-tuning but this set up seems the best so far in kicking on just before the fridge starts to struggle. So far it's keeping the fridge temp down to under 40...usually more like 34-35F.

[GeekSquadOfUn]

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.

[sully585]

Ok my fans are installed. I wired them to a hot 12v and put an inline switch on the positive side so I can turn them on and off when I want. Keeping fingers crossed. Only issue I had was the baffle is really high and really close to my vent so I couldn’t get the tilt I wanted on the fans. I thought about cutting the baffle out but others on here have recommended against that.

[7Iron]

I rewired my fans and thermostat. On the left end (fwd) of the condenser is the thermostat that turns on the factory installed fans. It is a normally open heat sensing switch, that closes at specific temp (I don't recall what the temp is) and allows power (12v) to go to the fans.

There are two wires, both red, on that thermostat one is always hot when refrig is turned on the second is hot when the switch closes at X degrees.

So I cut both and wired the hot to my new digital/adjustable temp thermostat input and tied the new and factory fans to the output side of the of the thermostat.

Now all 7 fans (3 new 650cfm/140mm and the 4 smaller factory installed) all come on at the same time and go off at the same time. And because the hot comes from the control board , it is only hot when the refrig is on.

We used this setup for 10 days at the end of Sept in southern Alabama, where temp records were broken just about every day....the warmest the refrig got was 40 , but just for a very short time when I had the doors open longer to instal an internal fan. The mode was 31-34...set on 5 with the exterior fan thermostat to turn on at 95 and off at 91.4 (35 and 33 C).

I am not recommending this instal, as it no doubt violates my refrig warranty, and probably my chassis , tires , ac, stove and everything else.

But I am really tickled and my problem has been solved....

thanks to everyone in this thread who provided ideas and solutions.

dg

[GeekSquadOfUn]

This collaboration lead to real, concrete solutions.

Time for a cold beer ��

[Jeff615]

I have come into this thread late but really glad I did. I'm also having problems with my fridge getting rather warm when the weather is hot. I want to install two fans to the back of my fridge. I am grateful for all of the info you all talked about here. Now my question, is it best to install all the fans at the bottom or top vent?

[jsb5717]

Solutions vary depending on which YouTube video you watch. I mounted mine in the top right inside the vent because I wanted to make sure that the air was directed back out while the air movement would also draw air from the bottom and up through the fins. It seems to have helped mine.

[GeekSquadOfUn]

I have come into this thread late but really glad I did. I'm also having problems with my fridge getting rather warm when the weather is hot. I want to install two fans to the back of my fridge. I am grateful for all of the info you all talked about here. Now my question, is it best to install all the fans at the bottom or top vent?
I think installing at the upper vent is easier and give you better results.

There is more space to install, and pulling air from bottom forces the warm air over the condenser. Finally you will not hear them as much, not that they are noisy.

Run the power wire down to connect and you're done. You can either use a little switch on the wire to turn ON or OFF, or install a little thermistor (essentially, a switch that opens or closes the circuit depending on the temperature) like I did, right next to the fans.

[WNY Bullet]

My single OEM fan was installed between the two openings and it was sooooo loud, I decided to remove it and install two more efficient, and quieter fans where the original single fan was. It was a pain to get to, but works so much better than the original and so much quieter, I have a hard time knowing when they are running.

[Customer1]

I have come into this thread late but really glad I did. I'm also having problems with my fridge getting rather warm when the weather is hot. I want to install two fans to the back of my fridge. I am grateful for all of the info you all talked about here. Now my question, is it best to install all the fans at the bottom or top vent?

Fans push much better than they pull

[JRTJH]

I also needed help ventilating my camper fridge. Before when it reached 90 degrees or higher outside my fridge couldn't keep up.

With no idea what brand, what size, what configuration, where it's installed or what condition it may be in, any help would only be a WAG, not sound advice. You might consider starting your own thread in the REPAIRS/MAINTENANCE section of the forum, give as much information as possible about the above "parts of the puzzle" and you'll likely get better information and recommendations. Right now, based on what you've provided, it could be anything from a "worn out 20 year old antique refrigerator to a fuse in a cooling fan circuit. Help us help you.....

[NMRandy]

I have a Norcold 2118, (double door 18 cu. ft.), in a slide. I had serious issues with the fridge getting to 40 deg F, (or higher), on a day over 90 deg F. I installed a 4" fan, with a plastic grille, on the upper cover, blowing outwards. I wired it to run constant. The fridge rarely get over 35 deg F. It solved my problem.

[Kevin J]

We have a single door, GE 8cu electric fridge on our 250bhs.
The fridge sits on the slide out.
I found this thread in my search; our fridge fan runs continuously; frost inside. Although it does seem to remain cold. It was more the noise and continuous running that I was investigating.

What is worrying reading this thread is our slide-out has no external vents on it.

[JRTJH]

We have a single door, GE 8cu electric fridge on our 250bhs.
The fridge sits on the slide out.
I found this thread in my search; our fridge fan runs continuously; frost inside. Although it does seem to remain cold. It was more the noise and continuous running that I was investigating.

What is worrying reading this thread is our slide-out has no external vents on it.

This thread is in reference to "gas absorption refrigerator use". That technology requires exterior venting to remove the hot air from around the cooling fins that is caused by the "excess heat from the gas flame or the electric heating element" that creates the "condensing/evaporation" process.

There's no telling what Keystone may have substituted in your trailer based on component shortages/component availability, but the "standard build" in the Bullet 250BHS is a Dometic gas/electric 8 CUFT two door refrigerator and the "optional build" is a GE 12 volt compressor driven 10.8 CUFT two door refrigerator. I'm not sure that GE even builds a 8 CUFT 12 volt single door refrigerator that's intended for RV use.

At any rate, if you do not have exterior venting for the refrigerator, then your refrigerator is NOT a gas absorption system. You have a "DC compressor refrigerator". Battery power drives a compressor that causes the "condensing/evaporation" process. There is no "excess heat from a burner flame" and no need for exterior venting in your refrigerator. It's an entirely different "system technology".

[Kevin J]

Hi John,

Sorry for the delay in responding, away at work.
Thanks for the reply and sharing your extensive knowledge.
You are correct, I do have the GE 12V larger electric-only fridge. I didn't appreciation the difference in fridge types and ventilation.
Fridge works well, and cools quickly but I do worry that it seems to run continuously and can be fairly noisy. I am not sure if anyone else with an electric-only finds that with theirs?

Thanks again.