Reefer Outside Fan Kit Install

[Mikec557]

First a big thank you to all who have posted "how to(s)". Learning from those allows me to tackle the projects I have taken on.

And fair warning, this is a long post.

Okay, here's the story. We full time and our fridge is a Dometic 2862, 2 door, 8 cubic foot, using either 120vac or propane. It's about 11 months old and we turned it off for maybe 2 months around the holidays. It is located inside the slide-out of our Reflection 29RS. By definition, this means that it struggles to exhaust the hot air out the upper access panel. During July and August, we were in a few locations that had 100-105 degree days. In some locations, the sun was beating down on the reefer side; in other locations, the reefer side was in the afternoon shade. Regardless, the inside of the reefer struggled to keep things cold. Nothing I hate worse than warm milk. Our model has only one fan, and its hooked to a thermostat mounted high on the back of the fridge, which I think is a 130 or 135 degree on/off switch. The fan would come on, but it was infective. I decided to install both outside fans to help move the air up the chimney and out; and inside fans to help circulate the cold air near the cold-sync on the inside back wall of the fridge. One or the other fan kit "may" have been sufficient, but I decided overkill was the way to go. I should mention that sometimes we put too much food inside the fridge, but we're full timing, that happens.

All that said, I think I should break this up into two threads so that other readers do not confuse the two modifications.

Outside Fan Kit:
I bought the two-fan kit from rvcoolingunit.com. It came with brackets that might work on another fridge, but there is no room in mine to use them. Ideally, you would mount these two fans inside the upper access panel, below the row of cooling fins. However, on our unit, both pieces of the chimney baffle are sheet metal screwed into place from the inside. You simply cannot get your hands into that area without pulling the fridge completely out of the slide.

So, the second best option is to install them inside the lower access panel. I decided to zip tie them into place. As you can see, one mounted perfectly horizontal, and one had to be placed at an angle due to the tubing that zig zags up through that area. Not perfect, but much more effective than nothing. This kit comes with a piggy-back 1/4 inch spade on the power source wire. This allowed me to remove the upper fan power source wire on the lower left of the circuit board, push on this power wire, and then push the upper fan wire onto the piggy-back connector. See pic.

The negative wire has an eyelet crimped onto it. There is a screw you can see in one of the pics that already has 6+ ground wires on it. I thought, what's one more? Do NOT use it. The jam nut came off easily enough, but when I tried to put it back on, after adding my wire, it was nearly impossible to keep the screw head from spinning. Eventually I used a small screwdriver that has a straight and phillips on each end bent at a 90-degree angle. I had to bend the sheet metal on the fridge upward a little, just to get it under it and onto the head of the screw. This is low amperage stuff we're doing here. If I had to do it again, I'd use a posi-tap and just tap one of the negative wires.

The fans, the 85 degree thermostat, and the pos/neg wire harness are all crimped with 1/4 inch spade connectors. All that was easy to put together. After I made the connections, I zip tied the wires to the propane hose as you can see in another of the pics. Throughout the night and early morning, the compartment is less than 85 degrees and the fans are off. However, once the sun gets up, regardless of power source (120v or propane), that compartment gets hot quick enough. So the fans do run quite a bit of the time. But it did help cool down the inside of the fridge, and that's what matters.

For boondocking concerns, the oem fan is marked at .46a. The outside fans are maked .17a each. I think the oem fan does not come on nearly enough. The extra fans may come on a little early at 85 degrees, but they do not use much power. But that's for boondockers to decide.





Edit to remove a wrong pic

Questions?

Mike

[chrisopy]

Hey Mike,

Where did you get your 85 degree switch, and anymore insight on how to wire it up. I also have the same fridge. Thanks.

[Fsalmy]

Hey Mike,

Where did you get your 85 degree switch, and anymore insight on how to wire it up. I also have the same fridge. Thanks.

I got mine from RV Cooling Unit Warehouse: https://rvcoolingunit.com/Fan-switch...-P4850272.aspx I cut the wires to the original 135* switch, added some spade connectors to the existing fan wires, plugged in the new switch and zip tied it at top of chimney.

[Mikec557]

Hey Mike,

Where did you get your 85 degree switch, and anymore insight on how to wire it up. I also have the same fridge. Thanks.

Hi

That's where I got mine as well, rvcoolingunit.com. I will add that being an 85 degree toggle, it came on every morning and ran into some time in the night. I only point that out for boondockers watching their amperage use. It was always so hot where we were that I needed them to run. Besides, the fans don't use much energy. I was very happy with the setup.

Mike

[chrisopy]

I got mine from RV Cooling Unit Warehouse: https://rvcoolingunit.com/Fan-switch...-P4850272.aspx I cut the wires to the original 135* switch, added some spade connectors to the existing fan wires, plugged in the new switch and zip tied it at top of chimney.

Hi

That's where I got mine as well, rvcoolingunit.com. I will add that being an 85 degree toggle, it came on every morning and ran into some time in the night. I only point that out for boondockers watching their amperage use. It was always so hot where we were that I needed them to run. Besides, the fans don't use much energy. I was very happy with the setup.

Mike

Thanks, I'm just thinking ahead on what I can do to maximize efficiency during hot weather. If one had problems with cooling even withe fridge on the coldest setting, would it be beneficial to experiment with moving the thermistor around, before adding any external fans?

[Mikec557]

Thanks, I'm just thinking ahead on what I can do to maximize efficiency during hot weather. If one had problems with cooling even withe fridge on the coldest setting, would it be beneficial to experiment with moving the thermistor around, before adding any external fans?

Well. We were in or near Boise, in August. Daytime was low 100s. The most you can do with the thermo probe inside the fridge is move it to the top most position on the fin. That was very insufficient for the heat we were in. To make matters worse, our fridge is in a slide out and came with only one fan. And it was inaccessible without pulling the fridge out from inside the RV. So I bought the fan kits from rvcoolingunit.com. I guess you have to decide about what your fridge presently has and what environment you may be camping in. My opinion is, if your fridge heat exits the roof of the rv, then add at least one fan. If it exists thru the side wall like ours, I'd add at least two fans.

Just my thoughts.
Mike

[mraplx]

Has anyone used one of these control units in the quest for lower fridge temps?


https://www.rvcoolingunit.com/Adjust...-P5784096.aspx

[Mikec557]

Has anyone used one of these control units in the quest for lower fridge temps?


https://www.rvcoolingunit.com/Adjust...-P5784096.aspx

For $26 I'd give it a try. I don't know how useful a variable on/off control would be. But a cold fridge is a good fridge. Back to Boise at 100+, I don't think my oem fan came on anywhere near earlier enough. Despite us roasting, the oem fan was off more than it was on. I don't know, maybe I'm just a gadget guy, but I've made many mistakes bigger than $26. I'd give it a try.

[mraplx]

For $26 I'd give it a try. I don't know how useful a variable on/off control would be. But a cold fridge is a good fridge. Back to Boise at 100+, I don't think my oem fan came on anywhere near earlier enough. Despite us roasting, the oem fan was off more than it was on. I don't know, maybe I'm just a gadget guy, but I've made many mistakes bigger than $26. I'd give it a try.

I am thinking about picking one up. I recently installed the internal fan unit from the same company and added 2 200mm fans to the upper vent stack. I am wondering if it is really necessary to turn the exhaust fans on and off? The original fans are still controlled by the factory thermostat, but the new exhaust fans are currently setup to run whenever the fridge is on. We are headed out to the desert this weekend where the forecast is 111, 109, & 107. So I'll see if the new exhaust fans made a difference. If I end up installing the controller I'll report back with my findings.


Internal fan unit.
https://rvcoolingunit.com/Norcold-N2...-P5946557.aspx

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

[Mikec557]

I am thinking about picking one up. I recently installed the internal fan unit from the same company and added 2 200mm fans to the upper vent stack. I am wondering if it is really necessary to turn the exhaust fans on and off? The original fans are still controlled by the factory thermostat, but the new exhaust fans are currently setup to run whenever the fridge is on. We are headed out to the desert this weekend where the forecast is 111, 109, & 107. So I'll see if the new exhaust fans made a difference. If I end up installing the controller I'll report back with my findings.


Internal fan unit.
https://rvcoolingunit.com/Norcold-N2...-P5946557.aspx

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

Didn't the external fan kit come with an 85 deg thermostat as part of the wiring it came with? One way or another, at those outside temps you'll want the external fans on to increase the heat dissipation. Let us know what the fridge inside temps are while you're camping there.

Edit: I just realized you bought fans only at Amazon, not a kit.