Questions on the Dometic RM2351 fridge cooling and adding exhaust fans

Xerofall · 07-02-2020, 12:04 PM

I've not had a working fridge in a camper before. I've been an ice cooler guy so far. I know how they work, how they're powered, but I have a question about exhaust fans.

First a little background.

It's been plugged in/gassed up for the past couple weeks. The fridge works. Freezer is cold. But like a lot of people mention, the fridge can warm up pretty drastically. I've come to realize a lot of it is affected by the outside temps. Here in Utah there's a joke that if you don't like the weather, wait a few minutes.

We had a 95 degree day the other day and the temp inside the fridge shot up to 72 degrees. The VERY next day the temps were low 50s with rain and even snow in the higher mountains (not kidding) and the temps stabilized back down to the 30-40 range. I've tested the temps on both electric and propane with the same results. The freezer being the only constant 20-32 range no matter what.

That being said, would adding small exhaust fans help dissapate some of that heat from the back of the fridge? I've heard both positive and not so positive discussion and I was wondering what you all thought. Do you think it would help, or would it not be anything noticable? I've heard it both ways.

I see APD (Alan) installed a squirrel cage type fan that helps him... I'm leaning more toward keeping it 12v and small like computer sized cooling fans.

Also, they sell little circulating fans for the inside of the fridge, does those work or are they a waste of time?

Xerofall · 07-02-2020, 12:14 PM

This is the 12v system I'm looking into...

https://www.amazon.com/dp/B07F2K5GCW/ref=emc_b_5_t

profdant139 · 07-02-2020, 01:17 PM

I have the same model, I think -- and a 12v fan would be great, except that we boondock a lot and can't afford the drain on the juice.

Here is a "non-electric" solution -- improve the airflow over the coils:

https://lookmomimcamping.blogspot.co...nsulation.html

If you open up the vents behind the fridge, you will see a lot of empty uninsulated space where hot air circulates around the sides of the fridge. That post describes a project where I filled in the voids and then created a flue deflector to channel the heat outward.

But in 106 degree temps (which we often see in the desert), the fridge is going to struggle, no matter what, I think.

APD · 07-02-2020, 01:30 PM

We opened up the space at the top behind the refrig. It would be at the back of your cabinet but on ours in was behind the microwave that's mounted in that space. We moved that back wall forward to open up and improve the restricted air flow to the upper vent. The FK models were build in a way that almost covers that vent.

Added insulation and a fan set-up. Actually added a 12 volt and a 120 volt so we could use either. Helped to cut the cool down time a bunch and it holds in Georgia/Florida heat as well.

APD · 07-02-2020, 01:43 PM

Oh. We use one of those little blue battery fans inside the fridge too. Helps a lot.
You probably all ready know this but plan on a small bungee or a aux latch for the fridge to insure the door stays shut if you travel off the pavement. They CAN come open and dump your beer and bologna on the floor.

Xerofall · 07-02-2020, 02:45 PM

Quote:

Originally Posted by profdant139

I have the same model, I think -- and a 12v fan would be great, except that we boondock a lot and can't afford the drain on the juice.

Here is a "non-electric" solution -- improve the airflow over the coils:

https://lookmomimcamping.blogspot.co...nsulation.html

If you open up the vents behind the fridge, you will see a lot of empty uninsulated space where hot air circulates around the sides of the fridge. That post describes a project where I filled in the voids and then created a flue deflector to channel the heat outward.

But in 106 degree temps (which we often see in the desert), the fridge is going to struggle, no matter what, I think.

Thanks Dan. I absolutely will not camp in heat above the 90s. However we might not have a choice sometimes. I was born in Tucson Arizona so you'd think it wouldn't phase me... but I do not function well in heat. I would be happy if I was living in Antarctica in fact!

Utah has two temps. Burning ass hot and freezing ass cold. Sometimes both on the same day!

We typically go higher up in elevation as it gets hotter, so in the end we might be okay once we're there... however I want to be able to cool and load the fridge before we leave and not have to worry about the fridge temps... however if we have to keep the ice chests so be it.

I will crack open the side panels and take another look to see if we have similar setups and I'll fab up something like you did. Thanks for the help.

Looks like I might have two sets of fans in my future, inside and out.

I'm less worried about battery power as I'm planning on doing a small solar job on the trailer and I have dual batteries on my Jeep if need be.

Agnitio · 07-12-2020, 02:27 PM

You should check the fridge installation clearances. Cruiser often installs them with to much clearance and without the required flue baffles. Tight clearances are better because air can’t circumvent/bypass the cooling fins - air has to pass through them.

mjpguy · 07-12-2020, 02:43 PM

I hear ya Jim, I live down in the St. George area. It's freekin' hot. It's been 106-110 here lately. my fridge works pretty well, even here but I like the idea of a little help so let me know how the fan thing works out for you. I'm wondering if it would work well in the refer's outside access area, there seems to be room in there for an exhaust fan.

FunFindsUs! · 07-12-2020, 04:16 PM

Xerofall,
Like you I live and camp in Utah. We have installed 2 computer fans in rooftop vent and a circulating fan in the fridge on one of the wire shelf and also on the cooling fins inside. I wired all these to the fridge inside light so they only run when the fridge is on. We never see temps above 45 degrees in the fridge and freezer stays below 30. We also have a accutemp system with a temp gauge we place in freezer and fridge with monitor magneticly mounted on front of fridge so at a glance we can see current temps and the highs/lows. I have not noticed a significant volt draw on batteries either.

casadelydia · 07-13-2020, 11:52 AM

Quote:

Originally Posted by FunFindsUs!

Xerofall,
Like you I live and camp in Utah. We have installed 2 computer fans in rooftop vent and a circulating fan in the fridge on one of the wire shelf and also on the cooling fins inside. I wired all these to the fridge inside light so they only run when the fridge is on. We never see temps above 45 degrees in the fridge and freezer stays below 30. We also have a accutemp system with a temp gauge we place in freezer and fridge with monitor magneticly mounted on front of fridge so at a glance we can see current temps and the highs/lows. I have not noticed a significant volt draw on batteries either.

Hi, do you have a link where I can buy an accutemp system with a monitor like you're talking about? We're camping right now in Florida and it's pushing 95 degrees. Our freezer is fine...but fridge is about 60. Gotta boost it up with a couple of fans inside and out, I'm guessing... Your idea of the temp gauge mounted on the front of the fridge is awesome.

FunFindsUs! · 07-13-2020, 04:10 PM

Casadelydia

Here is the link of the fridge temp system. I was wrong on the name. It is acu-rite. I bought it on Amazon for $40.

https://www.amazon.com/dp/B004QJVU78/ref=cm_sw_r_cp_awdb_t1_pSndFb0Z8C1E1

If you do fans I would suggest putting 2 in the rooftop vent to get air flowing through the coils between your fridge and outside wall. When I put mine in and tried them out I could really feel the hot air being pulled out. I also included a pic of the acu-rite.

Xerofall · 07-15-2020, 07:53 AM

I wish my fridge had an inside light to tap off of... but it's just a basic model. I'll have to find another source of 12v if I want a fan inside the fridge.

I did buy this for the outside vent, hopefully to move the hot air along better than without it. I'll look into that thermometer setup, thanks for posting the link.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Xerofall · 07-15-2020, 02:08 PM

One more thing, I need to see if the front panel can be removed. I'd like to cut a piece of metal and slide it back in so I can use magnets on the front. (we do magnets for all the places we go.)

Xerofall · 07-28-2020, 12:58 PM

So I got the fan installed and it blows (in a good way.)

My question is the fridge is topped by fiberglass insulation... is this required? Seems to stifle and retain the heat, not allowing air to flow around it.

I think all the pictures you guys have posted show no insulation on the top back of the fridge... so do I need to leave it, or can I take it out?

APD · 07-28-2020, 05:43 PM

I actually added some insulation to the sides and top. All the "workings" are on the rear so as long as it doesn't block air flow to those parts you should be good.
Is inside the top vent an open area? Ours was partially blocked by the inside cabinet shelf that extended to the outside wall and blocked about half of that vent opening. Might be a FK thing, IDK.
I opened that up by boxing out a portion of the back of the shelf to allow air to exit more freely. Seemed to help a lot.

profdant139 · 07-28-2020, 06:02 PM

I agree that the space around and above the fridge should be insulated, but NOT the back. Here is a blog post about my effort to use the space above the fridge for storage:

https://lookmomimcamping.blogspot.co...ightstand.html

**LJAZ** · 07-29-2020, 08:51 AM

As long as the you have clear area for air flow above the condenser so that the heat can rise unimpeded you should be good. Insulation on the top and sides will help to maintain the inside temperature.

Xerofall · 07-29-2020, 09:53 AM

Yeah, being up in the mountains and temps being in the high 70s and below, the fridge did okay.

I'm just a bitter old man... we can send satellites into space, land probes on a comet and more... but we can't figure out how to make a low powered fridge keep cool in heat. Don't get me started on a more efficient solar powered air conditioner, or why turning a compressor requires so much energy.

I'm guessing it's not a global priority, hahaha.

runner421 · 07-29-2020, 01:11 PM

I sometimes find myself in some very warm places, no shore power so I have to rely on the 12V fans and solar system. That being said, check out the aux fans at https://rvcoolingunit.com/ I've put one of these inside the refrigerator. I also added a 12V fan to move air through/over the evaporative coils. When it gets really hot I remove the grill to the evaporative coils to maximize airflow. It helps and I monitor the temps with the dual zone thermometer. RV cooling unit has lots of good ideas for tapping in to 12V sources. One even involves running the wire through the refrigerator drain tray/tube to get to the wiring behind the refrigerator.

Xerofall · 07-29-2020, 02:52 PM

Quote:

Originally Posted by runner421

I sometimes find myself in some very warm places, no shore power so I have to rely on the 12V fans and solar system. That being said, check out the aux fans at https://rvcoolingunit.com/ I've put one of these inside the refrigerator. I also added a 12V fan to move air through/over the evaporative coils. When it gets really hot I remove the grill to the evaporative coils to maximize airflow. It helps and I monitor the temps with the dual zone thermometer. RV cooling unit has lots of good ideas for tapping in to 12V sources. One even involves running the wire through the refrigerator drain tray/tube to get to the wiring behind the refrigerator.

I did two on the outside vent. It helped. I was thinking about running a wire through the drain tube hole to power an inside fan. I used a small Dollar Tree battery operated fan for the inside, it helped too, but took up a lot of real estate.

I hadn't thought about taking the side panels off completely when camped... that's a good idea. Thanks.