Design purpose of sheet metal covering 2/3 of the side top vent of the refrigerator on the 3010RE?

[Seaulayter]

We have had a cooling issue with our Norcold 120 refrigerator in our 2013 Bighorn 3010RE this summer and are currently working with our mobile RV repairman & Norcold to solve this cooling issue. Norcold is saying that this could be a design flaw with the airflow behind the refrigerator in our 3010RE.

There's a thermostat switch that closes at 125 and opens at 105 that provides the 12VDC to the two circulation fans to regulate the temperature behind the refrigerator. This is located above this sheet metal that covers 2/3 of the side top vent (see pic). I've placed a digital thermometer at this switch and it appears that once the temperature raises to 115 the refrigerator stops cooling and the refrigerator inside temperature begins to increase. However, once the fans kick-in at 125 and the heat begins to vent out the side top vent the refrigerator begins cooling again and the rrefrigerator inside temperature begins decreasing.

So to make a short question long - What is the design purpose of this sheet metal that coveres 2/3 of the side top vent of the refrigerature on the 3010RE?

 

[danemayer]

Re: ATF: Bighorn - Design purpose of sheet metal covering 2/3 of the side top vent of the refrigerator on the 3010R

Hi Seaulater,

The sheet metal is a baffle that directs air as it rises. When refrigerators transfer heat from inside to outside, the heat transfers to fins on the back and has to be removed through the vents to the outside. Air goes in the lower set of vents behind the refrigerator and exits through the top.

Proper installation of the baffle is important to moving air over the hot fins and out the vent. The attached diagram shows Norcold baffle installation with sidewall venting. The baffle installed by Heartland might need adjustment to match the specification shown in the attached diagram.

There may be other problems with the refrigerator.

The fans push air when the temp behind the frig climbs to a preset value - around 125 as you noted. But the thermostat for the fans has to be correctly located close to the fins or it won't come on early enough and the refrigerator won't cool properly.

There can be other problems as well. For example, if the refrigerator doors are leaking air, nothing done on the back of the refrigerator will help. If you find that the freezer is working correctly, but the refrigerator is not, you have an air leak.

Thermistor location inside the refrigerator compartment can also be a problem.

The refrigerator has to be level or it won't work properly.

 

[Seaulayter]

Re: ATF: Bighorn - Design purpose of sheet metal covering 2/3 of the side top vent of the refrigerator on the 3010R

Thanks for the quick response Dan and for furnishing the diagram that I will provide to our mobile RV repairman. The measurements for "Opening between condenser fins and baffle 0 - 1/4 in." and "Distance between bottom of condenser fins and top baffle 0 - 1/4 in." are incorrect on my unit. I will have my repairman correct these and see if this improves the cooling.

We did have a defective/faulty thermistor that was replaced that corrected the major issue we were encountering, also verified seals and level that your user guides addressed, which have been very helpful for me and Thank You Very Much for putting this on this user forum. Our unit has been cooling correctly for the past three weeks since we replaced the thermistor, but I had observed that during the hottest part of the day the refrig inside temp would begin to increase for several hours and then return to a 35-37 range after the sun would set. This had me concerned as we are preparing to leave on another trip soon.

Question: Do you think by replacing the thermostat switch with one that closes at 110 and opens at 95 would improve the efficiency of the unit?

 

[danemayer]

Re: ATF: Bighorn - Design purpose of sheet metal covering 2/3 of the side top vent of the refrigerator on the 3010R

Turning the fans on at a lower temp may help, if ventilation is what's causing the problem. The fans will run more, which will draw more power. If you run the frig on propane and battery, it'll run the battery down faster. If the fan noise is noticeable, you'll notice it more. Other than that, I don't think changing the thermostat will be a problem.

I think your Norcold has a heater that come on periodically to clear moisture around the inside fins. Dometic 4 doors do this every 48 hours causing a temperature rise for 2 hours. Then the frig restarts. On the Dometic, turning trailer power and battery on at 4PM causes the temp cycle to occur from 4AM to 6AM, when it's coolest out. Turning it on at 8AM would cause it to defrost at 8PM when it can still be hot out. If your frig temp climbed a few degrees for a few hours, it might be due to normal operation of the heater. You might want to call Norcold and ask them how yours works.

 

[Seaulayter]

Re: ATF: Bighorn - Design purpose of sheet metal covering 2/3 of the side top vent of the refrigerator on the 3010R

Dan I contacted Norcold to see if the 1210 had a "a heater that come on periodically to clear moisture around the inside fins" - here is their response:

This model (Norcold 1210) does not have a heater. Our units automatically go into a frost management cycle every 49 hours to maintain frost and condensation. During this time the cooling unit turns off and the sensor on the fins inside the refer turn it back on once temperatures reach 39 degrees.

Logan - Consumer Service - Thetford Corp/Norcold Inc

Thanks again for the information as I now know what to expect from my unit . . .