Inside refrigerator fans

[Klem]

If I get a chance this weekend I'll try the tape job.

Here is some food for thought. I have talked to a number of 'frig geeks' about fans and in summary:
Place a slow moving fan pointing just under the fins to assist cold air moving down the back.
Or
Place a slow moving fan on the bottom in the front to push the cold air up and it should circulate down the back.

The more I look at the frig fix I think all that horsepower would be best placed behind the frig in the vent flue.

I'm at -- 6.7 refrigerator only at the moment. freezer out, thermistor moved down, power on 3 bars. Seems to be stable at 35-38 degrees f.

Ready to try for a freezer too!

Mel

[Parker]

In retrospect, the fins were sized for natural convection, which generally is sufficient. A little air movement inside the fridge to equalize the temperature makes sense, but the idea that there is a bunch of "extra coldness" available for just blowing against the fins is probably not realistic. So if we can get the fans working to help with evening out the temperature, then I guess they will be of some value anyway. I've also thought about flipping the individual fans over so they draw air in from the holes and then exhaust downward.

[cpaharley2008]

I'm under the opinion that the cold air blowing across the thermistor has no effect on the temperature operation of the refrigerator. Wind chill does not affect inanimate objects, just humans. That said, the fridge fix eliminates frost build up which effects performance. That is why you have to manually defrost the non frost free units years ago. Now the fans inside the modern units eliminate that chore.
Our problem is not cooling, the freezer works fine, it will go down to -0- but yet our refer is at 44 degrees. It is controlling that cooling that seems to be an issue in the refrigerator section. The thermistor, IMHO needs to be replaced or an adjustable one utilized, like a thermostat. Our controls on the front of the refer are not operating as they should as a thermostat to control the inside temperature because it will freeze the freezer but not cool the refer, it is the controls that need to be fine tuned, not the cooling, just my .02 worth.

[Kountrykamper]

When your blowing air across a cold evaporator coil that is not wind chill. That air will be cooled (or actually have some of the heat removed) then pass over the sensor.

Frost is eliminated in modern refrigerator by a defrost cycle. IE turning the compressor off and blowing air over the coils and by turning on a heater that warms the freezer coil in most cases. You can not defrost a freezer coil with 0-10 degree air passing across it.

http://www.appliance411.com/faq/howdefrostworks.shtml

[Parker]

More disappointing numbers with the FF fan. Our camper is stored inside an enclosed space with the temperature relatively constant at around 80 degrees. Two days ago, I turned on our fridge with 120V. Yesterday, it measured 5 in the freezer and 33 in the fridge, with five bars selected. I installed the Fridge Fix fan with the holes taped over and the end plugs removed so it would circulate air without blowing right on the fins and thermistor. Today the temps were 6 and 44 degrees. I don't think it's a thermistor issue since the freezer only went up one degree. This tells me that blowing a lot of air around inside the fridge is not helpful, and apparently detrimental to cooling performance. Maybe the walls and door are not all that well insulated and the extra air motion is actually helping to transfer heat into the interior. I think a small fan somewhere on a lower shelf, either battery powered or wired in like KountryKamper's version, is about the best we can do, mainly just to equalize the temperature distribution. I think I'll go ahead and try wiring the FF fans in series to slow them way down, and if that fails, time to move on to other things.

[dave macrae]

I wonder if with the fridge fix fan the air is moving too quickly over the fins to exchange the temperature. Sort of like In a car engine if you remove the thermostat it will
Over heat because the coolant isn't in the rad long enough to transfer the heat.

[markvt]

This post is only met to show my mileage with out Dometic 6.7 Fridge.

Dometic Refrig with fridge Fix Fan installed AC
Power 120 V Fridge side 100% Shaded

6hrs 50 min fr 02* F Refrig 39*delta 37* ODT 71*
22/July/2014 8:00 AM Freezer 10 F Fridge 45 F ODT 72 F Humidity 72 %
4:00PM Freezer 01*F Fridge 42 ODT 88*F Humidity 60%

23/July /2014. Set power level to four
6:15AM Freezer -08 F Fridge 35 F ODT 63 F Humidity 66%
11:30AM Freezer 04F Fridge 39 F ODT 66F Humidity 66%
3:23PM Freezer 03F Fridge 40 F ODT 70 F Humidity 64%
11:45PM Freezer -04Fridge 38 F ODT 59 F Humidity 62%

24/July/2014 Set to power level Four
8:00 AM Freezer 01F Fridge 38F ODT 56 F Humidity 59%. 12:45AM Freezer 01 F Fridge 39 F ODT 70 F Humidity 59%
7:00PM Freezer 0 F Fridge 40 F ODT 67 F Humidity 43%
11:18PM Freezer -06 F Fridge 35 F ODT 64 F Humidity 52%

25/July/2014 Set power level four
8:15AM Freezer -05 F Fridge 33 F ODT 65 F Humidity 64%
12:19PM Freezer -04 F Fridge 34 F ODT 64 F Humidity 60%
5:00PM Freezer -04 F Fridge 34 F ODT 64 F Humidity 60%



28/Aug/2014 Set power level power to level Five AC after arriving to campsite. ( Started 2 1/2 hour drive on 12V power level 5 left home with fridge temps at 47 F freezer 6 F this was after load some more food into the fridge. I keep the freezer day shimmed open about 3/8 of inch to see if this would help fridge stay colder. Trailer is park in 100% shade. )
4:30 PM Freezer 16 F Fridge 49 F ODT 73 F Humidity 70%
10:00 PM Freezer 09F Fridge 39 F ODT 65F Humidity 70%

29/Aug/2014 Set power level power to level Four AC
8:30 AM Freezer 04 F Fridge 32F ODT 65F Humidity 80%
1:00 PM Freezer 10 F Fridge 35 F ODT 76 F Humidity 76%
4:00 PM Freezer 10 F Fridge 35 F ODT 80 F Humidity 68%
10:00 PM Freezer 07 F Fridge 37 F ODT 73 F Humidity 68%

30/Aug/2014 Rained all night temperature raised in fridge over night don't know why I am thinking May be because of the high humidity. Raised power level back up to five AC
7:18 AM Freezer 9 F Fridge 41 F ODT 67 F Humidity 77%
8:00 AM Freezer 24 F Fridge 42 F ODT 67 F Humidity 80 % Opening and Closing fridge door for breakfast
11:00 PM Freezer 11F Fridge 40 ODT 65 F Humidity 80 %
Turned off the Fridge Fix Fan for the night to see if this would help lower the temperatures in the fridge.

31/Aug/2014
Turning off the Fridge Fix Fan seem to help again not sure.
7:00 AM Freezer 9 F Fridge 34 F ODT 67 F Humidity 82 %
10:00 AM Freezer 9 F Fridge 34 F ODT 67 F Humidity 77%
Set power level down to 4
4:30 PM Freezer 12 F Fridge 39 F ODT 67F Humidity 43 %

1/Sept/2014
9:30 AM Freezer 10 Fridge 39 ODT 71 F
Temperature after 2 1/2 hour drive home on 12V power level 5
12:00 PM freezer 20 Fridge 40

[Rossue]

Originally Posted by cpaharley2008

The white wire is the feed wire for power, not the brown wire. The ground clip has to be firmly attached to the rear fins for a good ground. Go to post #175 here for pictures of install
https://www.escapeforum.org/forums/f...e-4109-18.html

Can't remember who posted this item originally- has been in a closet at home for at least two years. Decided to finally do install, which was fairly easy after reading this thread. Yesterday I turned on the 6.7 fridge to highest setting at after wiring this up around 2 PM. At 9 PM is was at 37 degrees; this AM it was at 32- empty fridge. Have never been below 40.
This is where I bought it; https://rvcoolingunit.com/Dometic-3-...-P5672097.aspx they now only offer a 3 fan unit that looks like the one Jim shows. Very simple to wire up; using a spade connector to white wire inside the fridge light housing and red wire of fan. Ignore black fan wire as the clips to fridge fins provide the ground. Carefully pry off cover of fridge light cover from the front under two dot tabs.

[Vermilye]

I purchased & use the same two unit fan. I purchased it from an eBay supplier that no longer has them. They seem to come & go on eBay, but are much less expensive than those available from trailer suppliers. This is a current example.