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BobJones · 10-01-2020, 05:07 PM

Hi guys!

I've been working on my Norcold fridge and, actually, having some success. I just had some cereal and the milk was cold enough to bother my teeth

That's one way to measure success

One of my fridge doors is loaded with pop cans. They've been in there long enough to be fully cold. What I'm noticing is that the cans at the top of the door are very cold and the ones at the bottom of the door are considerably warmer.

This leads me to understand that there is uneven cooling in the fridge and that others have solved this by installing a fridge fan. I looked around, and all the people that used to make them seem to have gone away. So I was thinking about making one myself as a fun and relatively easy to do project.

So, I'm looking for design ideas. It seems that they were originally powering these off the fridge light?

As for location, I was thinking it would be smarter to have the fan on the bottom blowing the warmer air up. This would not only mix the air but also send the warm air up to the sensor making it more accurately able to control the cooling.

Also, should it run 24x7, be temperature controlled or on a timer circuit?

fcbbob15 · 10-01-2020, 07:11 PM

Bob I installed a kit on mine with four fans and it works great. It mounts to the fins. I thought I got it from RV upgrade store but can't find it on there site. If you do a search you'll find many available. Otherwise a couple of small 12 volt fans should work. I would put them on the fins. My fans run when the fridge is turned on 24/7. I also installed the ARP fridge defend control to keep things from overheating and causing a fire. I added four fans just below the roof vent that the ARP control turns on when needed. I recommend all of the above mods. My fridge is always cold now and will easily get to -2 in the freezer and 27 in the fridge. Went from a control setting of 9 and now run at 4.

FireballMike · 10-01-2020, 07:35 PM

JC Refrigeration makes a fin fan that works very well.
I got it as part of the compressor upgrade.

https://jc-refrigeration.com/product...an-23-a-12v-u/

tpaul · 10-01-2020, 08:21 PM

I got this one although it says it is currently unavailable.

https://www.amazon.com/Triple-Deluxe...artrvingnet-20

https://www.youtube.com/watch?v=x6Ueb94fyd0

Got power by running it down the drain tube to the back of the fridge. As mentioned in both videos.

https://www.youtube.com/watch?v=IO3EppMBfvE

rschreifels · 10-01-2020, 08:31 PM

I ordered/received the www.arprv.com Frid Defend but have not installed it, yet. But this safety unit claims to protect you from fire or premature frig failure. It also has an option to add two low power fans in the cooling compartment. You may want to look in to this.

BobJones · 10-01-2020, 11:18 PM

Quote:

Originally Posted by FireballMike

JC Refrigeration makes a fin fan that works very well.
I got it as part of the compressor upgrade.

https://jc-refrigeration.com/product...an-23-a-12v-u/

Way to go! I could not find one no matter what. That one looks good and it's reasonable. Hopefully they will ship it to Canada. A lot easier than making one

BobJones · 10-01-2020, 11:26 PM

Quote:

Originally Posted by fcbbob15

Bob I installed a kit on mine with four fans and it works great. It mounts to the fins. I thought I got it from RV upgrade store but can't find it on there site. If you do a search you'll find many available. Otherwise a couple of small 12 volt fans should work. I would put them on the fins. My fans run when the fridge is turned on 24/7. I also installed the ARP fridge defend control to keep things from overheating and causing a fire. I added four fans just below the roof vent that the ARP control turns on when needed. I recommend all of the above mods. My fridge is always cold now and will easily get to -2 in the freezer and 27 in the fridge. Went from a control setting of 9 and now run at 4.

^This !! I was just thinking about that and I realized something important. You're in Nevada and I'm in Canada. If you can get a cold fridge down there with your ambient temperatures than, all things being equal, I should be able to easily get that up here.

My ambients in winter are -7c to 10c (19.4 to 50 in American).In the summer, there are only about 3 days when they cooling fans actually come on. That's at the heat of the summer when it's 30c (86 in American).

This makes me think that the rear fan is probably not needed at all up here (at least in my area). I bet just the fin cooler would do it. This also makes me wonder, if I can get my temperature setting from 8 down to 4 I bet the fridge would use less power too.

I'm going to order up a fridge fan. Thanks, that was very encouraging once I took into account the ambient temps differences between us. Makes me wonder if my next problem will be my fridge is too cold!

Holy, I just checked your numbers, 27f is almost -3c and -2f is almost -19c. That's well into residential fridge range. And that would be, I assume, in Vegas with a sweltering ambient temperature?

Isaac-1 · 10-02-2020, 06:31 AM

Mine is a Dometic, not a Norcold, but my solution was to use a cheap low watt draw 12V fan connected to the refrigerator light power leads. I used a fan like this https://smile.amazon.com/ARCTIC-F12-...dp/B0119T0D4I/ This is a very low power, slow speed fan, so does not add any significant amount of total heat to the refrigerator, but moves the air around. I have it clipped to the fins on the back, I don't recall exactly how, but I think I used zip ties. The I used a couple of piggy back spade connectors like these https://smile.amazon.com/DZS-Elec-Co...dp/B0776PY5JK/ to tap off the the feed side power connector on the refrigerator light and run the wire along the side of the interior back to the fins. You may have to design something different to top onto the light fixture power, I liked this option as it was clean and did not require splicing any wires in tight quarters.

p.s. sorry for the lack of details, but I did this mod nearly 4 years ago, and it has been simply running 24x7 since. It does not take much air flow to make a big difference, and I have had no fin icing problems since installing it.

fcbbob15 · 10-03-2020, 11:58 AM

Bob, Yes that's in the summer. I highly recommend installing the ARP control and fans. You may not need four fans like me but at least two. The ARP is to help prevent damage to the boiler tube if the fridge is not level. (such as driving up a mountain grade) It can also help prevent fridge fires, In my opinion should come as standard equipment on all absorption refrigerators.

BobJones · 10-03-2020, 10:52 PM

Quote:

Originally Posted by Isaac-1

Mine is a Dometic, not a Norcold, but my solution was to use a cheap low watt draw 12V fan connected to the refrigerator light power leads. I used a fan like this https://smile.amazon.com/ARCTIC-F12-...dp/B0119T0D4I/ This is a very low power, slow speed fan, so does not add any significant amount of total heat to the refrigerator, but moves the air around. I have it clipped to the fins on the back, I don't recall exactly how, but I think I used zip ties. The I used a couple of piggy back spade connectors like these https://smile.amazon.com/DZS-Elec-Co...dp/B0776PY5JK/ to tap off the the feed side power connector on the refrigerator light and run the wire along the side of the interior back to the fins. You may have to design something different to top onto the light fixture power, I liked this option as it was clean and did not require splicing any wires in tight quarters.

p.s. sorry for the lack of details, but I did this mod nearly 4 years ago, and it has been simply running 24x7 since. It does not take much air flow to make a big difference, and I have had no fin icing problems since installing it.

That's an excellent idea, and I have several of these fans lying around. I'm wiring one up as we speak

Quote:

Originally Posted by fcbbob15

Bob, Yes that's in the summer. I highly recommend installing the ARP control and fans. You may not need four fans like me but at least two. The ARP is to help prevent damage to the boiler tube if the fridge is not level. (such as driving up a mountain grade) It can also help prevent fridge fires, In my opinion should come as standard equipment on all absorption refrigerators.

That's awesome!!

I ordered up one of those wireless temperature monitors for the fridge and the freezer, that way I can see definitively what the temps are before and after.

I have a 120mm fan lying around. I'm going to try one out and see what happens. I can always order the multi-fan solution as needed. When the monitor shows up I'll know exactly what the truth is

Many thanks guys, this is very encouraging. The size of the fridge is sufficient for me, if I can work around installing a residential fridge it will save me a lot of work and hassle.

Isaac-1 · 10-04-2020, 12:23 AM

Keep in mind not all 120mm fans are the same, some draw much more power than others, and therefore radiate that much more heat while operating. This is part of the reason I picked the fan I did, as it draws less than half as many amps as the average 120mm fan while moving less air, but still enough. More is not always better here.

BobJones · 10-04-2020, 12:24 AM

I was going to ask about that. The fan I have uses 2.4 watts. Don't know if that's a lot or a little.

EDIT: Apparently that's .2 Amps

Isaac-1 · 10-04-2020, 06:27 AM

.2 amps is the typical amount most 120mm non "high output" 12V computer fans draw, compare this to the .071 amps of the Arctic F12 Silent I linked to above (note the standard (non-Silent) Arctic F12 uses .24 amps), also note that 3 wire computer fans can be used with only 2 wires hooked up as the 3rd wire is a speed sensor. (4 wire PWM fans are a bit more complex though)

BobJones · 10-05-2020, 03:30 PM

Many thanks for the help. Here are some facts I've learned since picking up a remote temperature monitoring system.

1) The fridge MUST have airflow inside in order to get even cooling. So the circulating fan does NOT seem to be a gimmick. I'm seeing +5.5c on the bottom left door of the fridge and +1.4c on the second rack down on the same side. This means cooling is very uneven and I must have a fan.

2) I can't tap into the light for 12v power. The 12v power feed going up to the ceiling of the fridge is switched so when the doors are closed it's off. It looks to me like it must be switched by the circuit board.

3) I bought groceries last night. A case of pop, a case of bottled water and a lot of frozen food. The fridge, in it's current state, takes a LONG time to bring the temperature back down. My hope is that a fan will aid in this process.

My guess is that I will have to run the wires for the fan down through the drain tube into the bottom outside of the fridge in order to get permanent 12v power to the fan.

BTW, the FDA says that the ideal temperatures are -18c for the freezer and 4c for the fridge with the 4c being adjustable to your liking but 4c being the neighborhood to be in.