Adding fans to Dometic 1350 12 cu ft model

[TheLexx]

Late start to RV season this year due to Covid. I'm determined to not have food spoilage again as we did last year. To that end I want to add some computer fans to the upper and lower vent compartments.

The lower compartment looks clear enough with plenty of room. I was thinking of using some radial fans that really put out quite a bit of air. That way the air will be forced up the flue to the upper compartment. These come in all sorts of sizes.


The upper compartment OTOH is more problematic. There is a factory installed metal shield that I'm guessing acts as a flue of sorts. I measured the clearance between the vent cover and the shield and there's only 0.5" of space there. The space between the rows of vent holes is about 2.5". So I might be able to squeeze a number of small 50mm (about 2") fans up there. However these are very small fans and I'm not sure how effective they will be, even if I use 6 or more of them. You can see from the photo of the vent cover, the measuring tape sitting at that angle would not clear the metal flue.



As to the wiring, I'm going to use a thermal sensor so the fans kick on at 80 degrees.

As far as I can tell there is no AC outlet in the lower compartment. That means I have to tap into the 12v wires of the fridge. I'm a little nervous about that as I'm not sure where to tap into the wires.

Here's the lower compartment:


And the diagrams of the components and electrical:


Where do I tap into the 12v electrical? The diagram shows a 12V terminal block. Can I just use that?

Red is + and White is ground?

What's the maximum load I can have on there? If I use 6 fans in the upper compartment at 0.06A each, and 2 fans in the lower compartment that draw 0.95A each, that's a total of 2.26A not including the thermal controller.

[Kevin2282]

In the diagram to the top left of the electrical control board you will see a black relay. There was a bare leg on mine that went hot (+12V) when the refriderator was turned on. I use that to power two 200mm fans. I ran the power supply through a fused switch so I could turn them off if they are not needed. I put the fans on the lower vent blowing into the coils.

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

[TheLexx]

I've marked the relay and the terminal block. Am I correct that the naked leg on the black relay is the positive? And the terminal block is red/white + and white - ?

So I would wire the positive to the relay and the negative to the terminal block?


Would it be better to use the large 120mm fans on the lower compartment as you did, or would a high output radial type fan make any difference since it has a directed flow of air?

In the diagram to the top left of the electrical control board you will see a black relay. There was a bare leg on mine that went hot (+12V) when the refriderator was turned on. I use that to power two 200mm fans. I ran the power supply through a fused switch so I could turn them off if they are not needed. I put the fans on the lower vent blowing into the coils.

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

[Kevin2282]

Yes, but please verify with a voltmeter. One of the two bare legs will go hot when the refrigerator is turned on. The metal plate that the relay is attached to is also a ground. I use a stake on eye loop connector and a micro small sheet metal screw through one of the existing holes for the ground.

[TheLexx]

Yes, but please verify with a voltmeter. One of the two bare legs will go hot when the refrigerator is turned on. The metal plate that the relay is attached to is also a ground. I use a stake on eye loop connector and a micro small sheet metal screw through one of the existing holes for the ground.

Great information. Thank you! I'm hoping these mods make a difference. I'm tired of having unsafe temps and spoiled food!

[Kevin2282]

Me too. I also added these fans inside the fridge. There are two now and I will be adding two more for a total of four fans. The daisy chain together. I got tired of the battery powered pieces of junk. I ran the wire out by the hinge on the left side and used a USB 3.0 extension cord to get to the plug on the side of the fridge (we have the theater couch). I will try them all for the first time in a few weeks when we go to Durango, Colorado.

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

[TheLexx]

Me too. I also added these fans inside the fridge. There are two now and I will be adding two more for a total of four fans. The daisy chain together. I got tired of the battery powered pieces of junk. I ran the wire out by the hinge on the left side and used a USB 3.0 extension cord to get to the plug on the side of the fridge (we have the theater couch). I will try them all for the first time in a few weeks when we go to Durango, Colorado.

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

That should help somewhat. I ordered this unit from RV Cooling Unit Warehouse:
https://rvcoolingunit.com/RM1350-4-D...-P5920372.aspx

[nyfingerlakes]

That should help somewhat. I ordered this unit from RV Cooling Unit Warehouse:
https://rvcoolingunit.com/RM1350-4-D...-P5920372.aspx

I installed the Cooling Unit Warehouse model and it is great! We had problems with the fridge not holding the necessary temperature before, but now we have no problems keeping the temperature in the 30s.
Wife is happy!

[Kevin2282]

I may end up going to that type of fan system, but these were cheap to try and they are easy to move around. I just needed more air movement in that big box.

[nyfingerlakes]

I may end up going to that type of fan system, but these were cheap to try and they are easy to move around. I just needed more air movement in that big box.

Before I bought the Cooling Unit Warehouse unit, I had two battery-operated fans just to check out if moving the air inside the fridge would work. It did, so I went the installation route. I think you'll be fine with what you are installing.