javaseuf
California's Gold Coast
Senior Member
Joined: 03/30/2005
View Profile
|
When I operated my RV service business in Desert Hot Springs California, temperatures got into the 110 degree range.
I owned a RV myself and also worked on many refrigerators in others.
I can say this from my experience:
In a RV absorbsion refrigerator, if the unit is level, installed properly and operating properly, outside ambient temperature should have no affect on the cooling performance.
With my current TT, I have a Dometic refer that operats 24/7 and has for the last two years. The inside temperature of the refer stys at a constant 31-34 degrees according to my digital thermometer. This is with our Valley temps reaching sometimes into the 108 degree range.
I use no fans behind the cooling unit nor any fans inside the refer.
Now I know that some will say I am wrong when I state that ambient temps shouldn't affect an RV refer but I am stating this from my own experience with the RV's I have owned and serviced.
And adding fans in the rear could certainly help the situation but my take is that the units that fans help have an issue with either improper installation/venting or other issues.
Many, many RV's I have seen DO NOT install the refers nor provide adequate venting/baffling as recommended by the refer manufacturers.
That void many RV's have above the refers are rarely sealed off from the rear as they should be and this is a major cause of refer venting problems.
Let me also mention that when I would visit the factory where I purchased my re-built cooling units from, they would have 10 rebuilt units (the cooling units only, no box) on a test rack, all connected
to 110-volts and testing in a warehouse/shop with very high indoor temps and they would have frost on the freezer plates.
Steve
2007 Springdale 291RKL
2003 F150 King Ranch
2001 Dodge Van w/Wheelchair Ramp
1991 Palomino Mustang PUP
Eureka Timberline Tent
Yamaha IF2400isc
Yamaha EF3000iSEBC
"Politically Incorrect And Proud Of It" 
|
dsolberg
Midwest
New Member
Joined: 03/17/2008
View Profile
 Offline
|
We just developed an RV Handyman DVD with #2 featuring RV Refrigerators. Absorption refrigerators create heat by "boiling" or percolating a solution that flows thru the tubing and evaporators and literally draws the heat out of the freezer and refrigerator. Thus, when you get into extreme heat situations, it becomes critical that all components are operating to max capacity. Norcold and others make an aftermarket fan that helps draw the hot air out from behind the refrigerator compartment. Some manufacturers install them in the factory, you should be able to see them attached to the upper coil by taking off the vent cover up on the roof or on the side at the top on other models and looking down inside. Don't install these on the floor of the refrigerator compartment even though it's an easier install. The cooling unit and other components block the flow and they are very inefficient. They are designed to install at the top on the solution pipe or tube. This may require removal of the ref on some models! Some are hard wired to a switch, others to a temperature sensor and come on automatically.
Here are a couple of other items to check:
Does your ref operate better on one source than the other? If it seems to be cooler on 120-V AC, then you may have a dirty or partially plugged burner assembly? It's a good idea to use an air compressor and blow out the supply line just before the electrode, the burner, and as far up the "flue" as you can. Wear safety glasses as this could be messy! There is also a certain type of spider that loves the smell of propane and often spins a web in this area which blocks or impedes the flow of LP. In this case you may need to use a pipe cleaner or wire to clean it out. It's also a good idea to blow out the back of the ref compartment as far up as you can get to ensure that there is no blockage. I have also seen some units that have the ref installed incorrectly, too close to the wall, or too much insulation, or insulation that has just fallen down blocking the venting. This requires a ref R&R. (remove & replace) Make sure the vent it not blocked with debris on the roof as well.
Also check the voltage coming in. Low battery voltage can cause an issue as it should be in the 11.5-13 range. Same with low AC voltage, should be 115-120.
Move your thermistor (temperature sensor inside on the fins) to a higher position that will sense the higher temp and adjust back at the board.
Check your door gasket seal. Doors can sag, seals can split, and cool air escapes.
Also try positioning your rig so the ref vent is not in the sun if possible?
|
fuzzbutt
Pittsburgh
Senior Member
Joined: 11/17/2006
View Profile
Offline
|
javaseuf wrote:fuzzbutt wrote:I had the same problem in Myrtle Beach last week. I did move the little sensor down on the fins in the fridge and that seemed to help a little.
I was looking at those fans at the Camping World there and wondering if it's worth the money or not.
Fuzz, just an FYI...........
To get the refer colder, the thermistor needs to be raised higher on the fins.
There was Ice at the top of the fins and not at the bottom. I figured if I slid it down, it would not sense the ice and run longer. Sounded good at the time. I will have to remember to slide it back up..
It wasn't as hot during the day after I adjusted it. That's probably why it seemed to get cooler.
Thanks!
John, Sherry & Sabrina
+ Mowgli (Keeshond) Sunny (Sun Conure) & Lily (Cockatiel)
94 Winnebago Adventurer 34'
04 Nissan Murano
98 Subaru Forester
92 Honda Gold Wing
Now.....bring me that horizon.
|
AlanB
Sierra Vista, AZ
Senior Member
Joined: 11/18/2002
View Profile
Offline
|
My previous refer was a norcold that was not cooling well in high desert temps, I added a fan at the top of the flu, just below the roof vent. The fan came with a thermistor and instructions (camping world). It did make a huge difference. Temps in the refer dropped almost 10 degrees while it was 110 outside. If the air flow on your flu is good, a fan might not make a lot of difference, but on mine it did. On my current motorhome, it came with two fans and it always works well, even when 114 outside.
AlanB
2002 Holiday Rambler Imperial 40PKDD Cummins ISL
|
nosaint3
Sioux Falls,SD
Senior Member
Joined: 02/06/2005
View Profile
|
Before I had my problem fixed, I put an 18 inch fan pointing up thru the vents and it did the job. Also good for troubleshooting.
nosaint3
|
|
|
LarryJM
NoVa
Senior Member
Joined: 11/09/2007
View Profile
|
As mention one thing a lot of RV Manufacturers skip on is sealing the back of the refer at the top so you don't have that dead space at the refer top which can effect cooling dramatically in hot weather. You need a good flow across the fins/coils up to the roof vent for proper cooling and fans at the top or bottom can help, but you still need the proper baffling so the air enters at the bottom and exits at the top and gets good flow across the fins/coils on the back of the refer.
Larry
2001 standard box 7.3L E-350 PSD Van with 4.10 rear and 2007 Holiday Rambler Aluma-Lite 8306S Been RV'ing since 1974. TRAILER MODS
|
fingertipvideo
LaPorte, Texas
New Member
Joined: 05/11/2008
View Profile
Offline
|
I personally went to Radio Shack and bought to large computer fans. I tied rapped them together side by side, wired them both together, installed a toggle switch in the positive lead and then tied both leads into the back of the RV where my refrig is located. I mounted teh fans so the blow upward towards the roof vent but the inlet to the fans were close to the intake grill. During setup when I get to a camp ground I just switch the fans on and let air circulate. The more air that you can pass across the coils the better the unit will work. Cost me about 20 bucks total and have had no problem cooling. My next effort will be to put a fan inside the refrig that will be battery operatored to circulate air around in there to even keep it cooler.
Have fun.
Fingertip
2006 KZ 315 Durango
F250 PS
|
Dennyf
Oneida New York 13421
Full Member
Joined: 12/13/2003
View Profile
Offline
|
The biggest problem i have found in refrigerator's not cooling when there seems to nothing wrong with them mechanically is the space between the cooling fins on the back of the refrigerator. The air entering from below up the back and through the fins is critical espically the space between the fins and the outside wall. This space needs to be as narrow as possible so all the air flowing up passes through the fins. When manufactures assemble these motorhomes that critical space is not always addressed. Hope this helps Denny
ADIRONDACK CAMPER
|
sparkydave
Macedonia, OH
Full Member
Joined: 01/22/2006
View Profile
|
Good info, I noticed my refrigerator doesn't seem to be working very well, even on AC power. Seems like it runs and runs and has a hard time getting down to 40 degrees since the thermostat never cycles off. Guess I'll try the fans and see if it makes a difference, since it does seem a bit warm in the back.
|
