Refrigerator Fan

bobmacc wrote:

pbitschura wrote:

bobmacc wrote:
I installed two of these fans in my Norcold 1210. Found they moved a lot of air well in the fridge but they caused moisture to accumulate on the fins at both sides of the fridge and then freeze. This resulted in reduced cooling capacity when the fins iced as the thermistor was in the affected area. As a result, the fridge cooling deteriorated and I removed them. Seems like a great idea in theory but in my case, it failed in practice. Cooling is now much better without them.
I also added a 160cfm muffin fan at the top vent. In my coach, the fridge is in a slide and it is difficult to exhaust the heat out the sidewall vent so the fan helped considerably in Florida this winter. Since then, I added two additional 160cfm fans that I can switch on and hope this will work well during the hot summer. Time will tell. Sounds to me that I wouldn't be fighting these battles with a residential fridge so who knows what time will bring!

In your case, was the fan in the frig on a lower shelf or blowing over the fins directly. It seems that the goal is to move cooled air away from the fins. A fan in the vent channel exterior to the frig has worked well on hot days and an interior fan may not be necessary. But I have all the parts on hand if it would be a benefit. Thanks.

I installed two of the fans shown in the RV Cooling Unit link above. These are low current dual fans mounted in an aluminum shroud. They attach directly to the fins and move a significant volume of cold air that has passed through the fins into the fridge. They obviously also blow cold air out of the fridge while the door is open. As others have suggested, a low volume fan on the bottom shelf might be more effective. Based on my circumstances, I have come to believe that moving cooling air through the rear vent is likely the best solution to optimizing interior cooling.

Thanks. I will play around some and report back with what I find. I plan to mount a computer fan on the fins to move air down where temps above 90 stress the frig to hold 40 degrees.

pbitschura wrote:

bobmacc wrote:
I installed two of these fans in my Norcold 1210. Found they moved a lot of air well in the fridge but they caused moisture to accumulate on the fins at both sides of the fridge and then freeze. This resulted in reduced cooling capacity when the fins iced as the thermistor was in the affected area. As a result, the fridge cooling deteriorated and I removed them. Seems like a great idea in theory but in my case, it failed in practice. Cooling is now much better without them.
I also added a 160cfm muffin fan at the top vent. In my coach, the fridge is in a slide and it is difficult to exhaust the heat out the sidewall vent so the fan helped considerably in Florida this winter. Since then, I added two additional 160cfm fans that I can switch on and hope this will work well during the hot summer. Time will tell. Sounds to me that I wouldn't be fighting these battles with a residential fridge so who knows what time will bring!

In your case, was the fan in the frig on a lower shelf or blowing over the fins directly. It seems that the goal is to move cooled air away from the fins. A fan in the vent channel exterior to the frig has worked well on hot days and an interior fan may not be necessary. But I have all the parts on hand if it would be a benefit. Thanks.

I installed two of the fans shown in the RV Cooling Unit link above. These are low current dual fans mounted in an aluminum shroud. They attach directly to the fins and move a significant volume of cold air that has passed through the fins into the fridge. They obviously also blow cold air out of the fridge while the door is open. As others have suggested, a low volume fan on the bottom shelf might be more effective. Based on my circumstances, I have come to believe that moving cooling air through the rear vent is likely the best solution to optimizing interior cooling.

landyacht318 wrote:
Keep in mind the computer fans generate a small amount of heat which also must be removed by the fridge.

Computer fans vary widely in the amount of air moved, for the current consumed and the noise made. Some companies Like Noctua make incredibly sophisticated fans. I employed one of their 120mm fans on my condenser that makes half the noise and uses less than half the current as the fan provided with the fridge.

For my interior fan, with my small 1.8 cubic foot compressor fridge, I sought out the 40mm fan with the least current consumption, at 0.03amps. It moves about 6.5 cfm. I have it blowing at the evaporator/coldplate 24/7, and it makes a huge difference.

Much more even internal temps.
A lower thermostat setting needed to achieve sub 35f everywhere in the box.
Much faster cool down of warm items placed within.

I took power from the LED light for the fan.

I would not want to cycle the fan as the hydro dynamic bearing lubricant was never intended to start in such cool temps. So far the fan will have been running nearly continuously for 2 years.

A similar fan (with a sleeve bearing) made it 5 years before becoming noisy, in my last fridge which failed.

So keep in mind the fact that not all fans are created equal. Huge variances exist in design and performance, and larger fans moving lots of air inside the fridge could easily negatively affect overall performance by adding a heat load, or by expelling cold air more efficiently whenever the door is opened.

All good points.

Keep in mind the computer fans generate a small amount of heat which also must be removed by the fridge.

Computer fans vary widely in the amount of air moved, for the current consumed and the noise made. Some companies Like Noctua make incredibly sophisticated fans. I employed one of their 120mm fans on my condenser that makes half the noise and uses less than half the current as the fan provided with the fridge.

For my interior fan, with my small 1.8 cubic foot compressor fridge, I sought out the 40mm fan with the least current consumption, at 0.03amps. It moves about 6.5 cfm. I have it blowing at the evaporator/coldplate 24/7, and it makes a huge difference.

Much more even internal temps.
A lower thermostat setting needed to achieve sub 35f everywhere in the box.
Much faster cool down of warm items placed within.

I took power from the LED light for the fan.

I would not want to cycle the fan as the hydro dynamic bearing lubricant was never intended to start in such cool temps. So far the fan will have been running nearly continuously for 2 years.

A similar fan (with a sleeve bearing) made it 5 years before becoming noisy, in my last fridge which failed.

So keep in mind the fact that not all fans are created equal. Huge variances exist in design and performance, and larger fans moving lots of air inside the fridge could easily negatively affect overall performance by adding a heat load, or by expelling cold air more efficiently whenever the door is opened.

bobmacc wrote:
I installed two of these fans in my Norcold 1210. Found they moved a lot of air well in the fridge but they caused moisture to accumulate on the fins at both sides of the fridge and then freeze. This resulted in reduced cooling capacity when the fins iced as the thermistor was in the affected area. As a result, the fridge cooling deteriorated and I removed them. Seems like a great idea in theory but in my case, it failed in practice. Cooling is now much better without them.
I also added a 160cfm muffin fan at the top vent. In my coach, the fridge is in a slide and it is difficult to exhaust the heat out the sidewall vent so the fan helped considerably in Florida this winter. Since then, I added two additional 160cfm fans that I can switch on and hope this will work well during the hot summer. Time will tell. Sounds to me that I wouldn't be fighting these battles with a residential fridge so who knows what time will bring!

In your case, was the fan in the frig on a lower shelf or blowing over the fins directly. It seems that the goal is to move cooled air away from the fins. A fan in the vent channel exterior to the frig has worked well on hot days and an interior fan may not be necessary. But I have all the parts on hand if it would be a benefit. Thanks.

I installed two of these fans in my Norcold 1210. Found they moved a lot of air well in the fridge but they caused moisture to accumulate on the fins at both sides of the fridge and then freeze. This resulted in reduced cooling capacity when the fins iced as the thermistor was in the affected area. As a result, the fridge cooling deteriorated and I removed them. Seems like a great idea in theory but in my case, it failed in practice. Cooling is now much better without them.
I also added a 160cfm muffin fan at the top vent. In my coach, the fridge is in a slide and it is difficult to exhaust the heat out the sidewall vent so the fan helped considerably in Florida this winter. Since then, I added two additional 160cfm fans that I can switch on and hope this will work well during the hot summer. Time will tell. Sounds to me that I wouldn't be fighting these battles with a residential fridge so who knows what time will bring!

mchero wrote:
Check out this link;
http://rvcoolingunit.com/Cooling-Performance-Enhancing-Items-C320215.aspx?sid=298

mchero: Thanks for sharing the identity of this source. I purchased a dual fan and it is quality. Easy to install.

I don't want to cut/splice wires, so I use a Valterra fan that runs for months on a set of two D batteries. It doesn't move much air, but it circulates enough to keep the fridge compartment cool.

My next rig, I'm probably going to go with 1-2 "computer fans" inside the refer compartment, as well as 1-2 at the top of the vent to help air circulate. That way, I don't have to worry about changing the D cell batteries every so often.

You can make your own just buy a 12v computer muffin fan attach it to a refrig. shelf attach the wires to the refrig. light so the fan runs when the light is off and turns off when the door opens. You just need to move the air inside the refrig.
same as using the fan that sat on the shelf and ran on 2 D size batt.

fuzzbutt wrote:
Mine helps. What worked better was installing 2 fans at the top of the vent outside.

I installed one in my outer vent but will do the same in the frig. Mine come from gutting a tower computer. Most have two fans, run on 12v and are extremely frugal in electrical usage, less than .3 amp per hour.