I'm not sure I have a problem because it is so stinking hot here, 103 F by our outside thermometer, but our refrigerator is not staying cool. It is now up to 68 degrees. The freezer is at 20 degrees. I have a fan blowing up through the coils on the outside cooling unit and an interior fan similar to two computer fans on the inside blowing at the fins. If anyone is in similar outside temperatures, what is your refrigerator temp. I really don't know if we have a problem. If have tried it on gas and electric with little variation.
I think the frig is worth putting a new cooling unit on since the interior is in very good condition. It is the original 1993 frig but still looks new. If someone has a link to the company that sells the replacement cooling units it would sure be appreciated.
All opinions are welcome.
From your description the fridge is dying. Open the access door on the outside and inspect the cooling unit. If you see any yellow stains or yellow power on any of the welds, bad news. I am going thru the fridge replacement routine now. Unless you do the entire cooling unit change yourself it could cost as much or more than a new unit. The lower cooling portion will clog or nearly clog while the freezer works fine.
It's 100 F here according to our outside thermometer. Our fridge has been cooling since 1 PM yesterday and is currently 36 degrees inside on the coldest setting. I didn't probe the freezer.
How long have you been trying to cool the fridge?
-M
The coils and everything on the outside look brand new, no rust or discoloration anywhere. I am amazed at the condition of the entire unit. We thought the frig had been replaced but the serial number is lower than Jeff & Carol's 1995 U320.
I do plan to do the replacement myself or if I can't I will buy a whole new unit. The biggest reason to replace the cooling unit is most often to install a new frig one would have to remove a window just to get the old one out and the new one in.
I have considered a residential frig but we have not yet established our full time lifestyle and I don't yet know if a residential will work for us.
Our frig has been on since last October. We just started noticing problems when all of this heat started about two weeks ago. However, from what you are saying I'd say we have a problem.
Kent,
Is the temperature probe still attached to the fins inside the fridge? It should be clipped on and you can slide it up (to go colder on a setting) or down (to go warmer). Ours has a habit of shimmying down to the bottom of the fin.
Of course I'm not sure that would be relevant here since your freezer is also acting up :(
-Michelle
Kent, are you oerating on LP Gas or Electric ? Our 01 coach refrig, had a problem on LP Gas, had a trouble light on panel, found the need to get rid of the stalagmite or stalagtite on fhs burner, just knock it off and end of issue. Not sure your issue is the same, but maybe.
Kent the Dometic 3962 RB will go thru the door with the fridge doors removed. $1389.00 @ Camping World on sale. Two year warranty. Camping World will do the install for $250. Presidents club member gets a coupon for free shipping and 25% off the install. Norcold will run $2000.00. Replacement cooling unit -$750-$1200 with no guarantee. Still an ouch, ouch.
Sounds like it is just too hot for it to cool efficiently. There could be some issues with a burner stack not being clean. If your ac voltage is low the heating element puts out less heat resulting in less cooling. Switching to gas should help with the voltage drop and help out the air conditioners if you have low AC voltage. Too much stuff in the refrig cuts down the cooling. Barry's website has lots of stuff about the refrig, more than just this. Refrigerator Not Maintaining Temperature (http://www.beamalarm.com/Documents/refrigerator-not-maintaning-temperature.htm)
Kent,
What refrigerator do you have now?
For comparison, our refrigerator is empty and operating with 120VAC. It is a Dometic with freezer on top and "regular" cold storage on the bottom. The coach is in the shade. The refrigerator has no auxiliary fans. Current conditions:
Coach interior is 89F (air conditioner thermostat at 86F)
Coach bay is 95F
Weather station nearby is 96F (down from high of 104F)
Freezer -7F to 9F (back to front)
Refrigerator 36F to 39F (fins are around 26F)
Interior temperatures were taken with an infrared spot thermometer.
The probe is in the clip on the right hand most fin. I have moved it up and down and pulled it off of the fin and can see not difference in the temperature. It works overnight but then warms up during the day.
Dave, as I mentioned I have tried it on both LP and electric, no difference.
It does max cooling with the temp probe ( clip) all the way up. Absorption units are poor at best in hot weather. But yours should do better than 68 in 100 degree air. Any adjustment you do takes a while to have any effect.
My frig is a Dometic, RM 7030 side by side. My voltage is running 114V on one leg and 120v on the other leg. I have checked the stack and the area behind the outside frig door. The coils are like new looking. There is no blockage of air flow through the top vent. I have even put a fan to help with circulation in the stack area. I have also installed an interior fan on the fins. So far, it cools down to 36 F at night and up to 68 during the days. These temps are taken at the bottom of the frig near the front.
I have removed the thermister clip and put it toward the front of the frig and it still doesn't cool. I am now convinced that I have either an inoperable thermister, circuit board or a clogged cooling unit. I'm going to try a jumper on the thermister pins first and then a circuit board if they are not too expensive. I am prepared to install an entire cooling unit if necessary.
Kent what is your voltage at night when the temperature comes down to 36 degrees? 114 vac is very low.
I will bet at night when everyone's a/c is off your voltage comes up & your refer cools down.
Is your refer vent in the back in the sun or shade? That can make a huge difference of heat to overcome.
If it is working properly at night when the outside temperature comes down, it sounds like the voltage is not adequate enough. It will take
many hours to see any difference in the cooling no matter what you are doing to diagnose it.
If it cools at night, would that mean these items are working ??
With those ambient temps it's really tasking the Dometic. Hold on Batman. As Barry says. Any adjustment takes hours to see any results. Get some dry ice and wait.
Switching over to gas to get away from the electric voltage issue, might be an interesting discovery. When I am not at home I run on gas most of the time, and I feel it does atleast as well, if not better than the AC mode. My tester is the ice cream stiffness, real high teck, maybe a lil red neck, but it works ;D
Kent
In case you have to repair or replace the RM 7030.
I had to replace our RM 7030 Sept. 2009. Had the yellow stuff leak out in the burner pipe close to the flame area lucky for me it was on electric and nothing was burned. Tried to replace the cooling unit twice but it had shipping damage both times. I gave up on replacing it after looking at cracks in the inside door plastic liner. I then ordered a new NDR 1292 with fans It's way nicer and has more room in side. The wife loves it.
The problem with the NDR 1292 it's 2 inches taller. I had to cut 1 inch from the top of the opening and 1 inch from the
bottom. The existing bottom was starting to break down and needed some work anyway. It turned out I could have cut 1/2 inch at the bottom and 1 1/2 inch at the top.(did the work before the NDR 1292 arrived) I did not need to modify the doors below the refrigerator opening
As luck would have it the existing wood door panels worked in the new doors ( they are shorter but are 1/4" longer then the
opening ) They worked and look great. They are glued to the existing rm 7030 doors but I was able to remove them with a long bladed knife not easy but dueable.
You need to remove the refg.doors to get it through the MH Door Also the wood strips in the step area.
The new refg. is working great and well worth the expence.
Hope the NDR 1292 is still are avilable
Good luck either way
Bob
94 U300se
I have not seen anyone responding about your refer being level, so, here is a thought.
About two years ago, our refer, a Dometic, started to do what your is doing. It seems that they are very sensitive to being level. Ours started to get warmer and warmer and we went through the same drill of figuring how to get it out, which one to replace it and how to get the new one in.
Because of how the system works (which someone with more refer knowledge could explain in minute detail here) the refer system needs to be level to work.
Bottom line is that we leveled the coach, burped the refer by rocking it (which didn't work, initially), used the ice maker to keep it cool while we tried to figure out what was wrong and how to fix it, drove around looking for a camping world to replace the refer and tried to decide which windshield was going to come out to get the new refer in.
Driving around on bumpy roads (compliments of Babette our bitch, excuse me, GPS) we must have burped the gasses and liquids to where they are supposed to be, everything is fine now and we are all happy campers with cold beer, cocktails, ice cream and a GPS that still complains when we don't listen to her.
Hope that yours is also only indigestion.
Happy Fathers day to all you guys, and to your women who let you enjoy one!! ;D
Bob, that is valuable information. My frig looks brand new inside and out. Seals are perfect, no cracks in plastic and latches are perfect so I think I will buy any components I need a restore this one if at all possible. I'm betting that I damaged the thermister by using a 12V trouble light probe that shorted out the thermister or the circuit board. I will know more tomorrow. If its the circuit board it sound like Dinosaur Electronics is the best source for a replacement.
Mike, we are dead level and have been for two months but that certainly can cause the kind of problems we are having. Thanks for the input.
Boy, what great information one can get from Foreforum Members and really fast as well.
Kent,
Is the outside wall behind the fridge exposed to direct sunlight? If so, could you remove the access door, mount anything that would hold a large sunshade creation in place? You might have to create such a device, but probably be able to market it to all the other summer inhabitants of the nether regions in hot weather.
There are some old threads that explain how to feel the temps on the coils in the back to see if the ammonia is cascading down the tubes to the bottom. Search on dometic in the old forums (when I had my problem) and see if it warm and where.
I've partied too much to help you tonight!!! ;D
Kent
Here is a link to a new replacement cooling unit RM 7030
RM7030 Dometic Brand-New Cooling Unit, built by the Amish - RV Cooling Unit (http://rvcoolingunit.com/RM7030-Dometic-Brand-New-Cooling-Unit-built-by-the-Amish-P401949.aspx)
Hope it works
Bob
Measure voltage on 12 volt gas valve and 120 volt heating element to be sure they are activated. We put small LED & neon lamps inside the kitchen to know if they were turned on. You can always connect an electric cord directly to the 120 volt heating element and plug it into an outlet to bypass everything.
The indicator lights, with our Chaney wireless remote refrigerator/freezer thermometer keep us informed what is going on during hot weather.
Our new Lowe's Whirlpool 120-volt $350 self-defrosting fridge is working great in 102 day temp and 90-80 degree nights. Our ice trays freeze in 5-hours so we make ice twice a day instead of every other day. We are very happy we made the switch. Our Walmart frozen food shopping today did not drive the inside temps up very much. And ice-cream is hard, which can be a disadvantage for us.
Fridge electric usage is exactly the same as our two Directv DVRs which is 0.4 amps (120-volt) average per hour for the last 20 days. About the equivalent of 34 amp-hours of battery drain for 8-hours of night time. Another Foretraveler just installed the same fridge in his coach. We have not tried to dry-camp since having the Whirlpool. 53 watts is no problem for inverters.
Barry & Cindy
Kent, Last resort test.
1. Turn everything off, find coil on gas valve and pull off connector, Jumper 12 Volts to gas valve coil to open it, manually lite flame with a match and observe closely for a couple hours. This will be giving you full flame under boiler and if unit cools then you have a control problem and a Dinosaur Board is in order.
2. As someone else suggested make a pigtail and attach 110 to heaters. Again if it cools its a board problem.
Good luck, If you need more FREE advice call me at 770-595-3891, I am sitting home with a new hip implant but my brain still seems to be working.,
Gary B
Testing the Cooling Unit Testing by " Feel " For this method of testing the only tools required are your hands!
CAUTION: some of the components may be
HOT! Be careful! If a cooling unit is operating properly, there should be approximately the same amount of heat in the middle sections of the boiler and absorber. A bad cooling unit will aways be HOT somewhere on the back. No heat at any location on the back after several hours could mean something other than a bad cooling unit.
Cooling unit blockages When a cooling unit malfunctions due to a blockage, the boiler section may be too hot to touch and the absorber will be relatively cool. Any blockage reduces the free flow of the solutions and will inhibit or completely prevent proper cooling operation.
Testing an Absorbsion Refrigerator Cooling Unit (http://beamalarm.com/Documents/testing_an_absorbsion_refrigerator_cooling_unit.html)
Lots of great ideas. Thanks to all.
I don't think it is the cooling unit because I have a freezer at 3 degrees and a frig at 60 F. The only thing I have messed with has been the thermister, if that's the right term, in the refrigerator area. When I was installing the "Fin Fan" I was looking for a 12V source and mistook the white thermister wire as a possible power source. I used my ever handy 12V trouble light and punctured the wire with its needle point. I saw a weak flashing light, not a constant 12V source so I am afraid that I may have shorted out the thermister with the test light. Per Bill Willet suggestion I have currently disconnected the thermister plug at the control board and the temperature is falling in the refrigerator part, down form 59 F to 46 F in less than 1/2 hour.
I hope it is as simple as installing a new thermister and not the cooling unit or circuit board. The refrigerator is in such good condition I really don't want to replace it. I will post the outcome as soon as I find out what's wrong.
Barry, I checked the elements on the back of the refrigerator with an IR thermometer. There is no cool spot or spots. The temperatures seem pretty consistent as you move up the coils.
The tank at the bottom is 136 F.
The lower most portion of the coil is 139. As you go up the coils each coil drops about 2 degrees until you reach the top coil at 114 F.
The finned portion at the top is 135 F.
The coils on the right hand side, the freezer side, are about 3 degrees hotter than the coils on the right. I don't know if this is good or bad. I would be interested how this compares to others. Remember, I have disconnected the thermister so the cooling unit is running at full power and is on 110V AC. Inside temp of fins in the refrigerator is down to 42 degrees from the starting point of 59 degrees an hour ago.
Kent, Looks like you are working towards a control board problem if you are down into the 40's in the box. Be patient and let it cool on manual AC for a day, may go below freezing but That's OK it will only confirm that coil is in operating condition..
Don't be afraid to install a new board. Dinosaur makes a replacement board that works great and costs about 125 bucks. Also as Bill W can tell you you can get an adjustable Thermistor that will allow you to control the temperature more precisely.
As Bill suggested, I went online last night and the Dinosaur site says they only sell through retailers. Does anyone have any suggestion where to find the best price?
Kent, Can't remember where I bought last one but here is a place to begin. Google Dinosaur Refrig parts for other sources.
Dinosaur P-711 Dometic Refrigerator Circuit Board (http://www.anyrvparts.com/ProductDetail.asp?PID=11229&SID=48&DID=70&CID=149&BID=)
Gary B
Just one more thing to add about this problem. Read this from Barry's website. It's about not being level and overheating the boiler. Foretravel (http://www.beamalarm.com/Documents/why_does_the_refrigerator_need_to_be_level.html) As I understand it when unlevel conditions are right for longer than about 15 - 20 minutes the sodium chromate precipitation can occur. According to the article this would only happen on older models and require several hours in a newer model. Is my 15 yr old refrig a newer or older model? Once it happens it cannot be reversed. This is easy enough to do when checking in at a campground, shopping, etc if you are not parked reasonably level. It seems that manufacturers could install a device that would shut off the refrigerator and sound an alarm when it is unlevel if they wanted too. It could not be something as simple as a mercury switch alone, it would have to include a timer to eliminate frequent shutoffs while driving. I try to remember to shut off the refrig when it isn't level, but many times I forget.
Gary, thanks for the link.
Jerry, I have never had this coach parked out of level but I have had it less than a year so no telling about the previous owner. However, from my experience and what I have read it takes quite a bit of out of level exposure to damage one of these units. I'm counting on it being my stupidity poking a hole in the thermister cable with a test light probe. We should know by tomorrow.
The latest update is that yesterday at 8:00 AM I disconnected the thermister from the circuit board. At that time the frig had been on all night set on 5 on the cooling scale and was at 59 degrees interior temp. Outside temp that night was 78 degrees. The frig fins dropped to 39 degress within 1 hour, taken with an IR thermometer. During the day, with the thermister disconnected and the outside temp reaching 102 degrees, the frig fin's temp went up to 59 degrees and the freezer shelf was at 3 degrees. The freezer seems to be still functioning adequately.
What I don't understand is how the freezer can be cold and the frig not cold. Isn't it all one cooling unit?
Last night, with the thermister still disconnected and the outside temps went down to 68 degrees. This morning the frig fins were down to 19 degrees and the freezer shelf to -7 degrees. It will be interesting to see how hot the frig portion gets today. The outside temps here are forecasted for only 92 degrees. It would seem apparent that the thermister is bad.
Yesterday at the suggestion of Bill Willet I spoke to David Force of RV Cooling Warehouse. He certainly seems to know what he's talking about and did not try to sell me a cooling unit. He said it sounded like beyond the bad thermister, improper initial installation of the refrigerator was the primary cause of my problems. He explained that the coil portion of the unit is designed to be flush with the outside wall. This forces the air flowing from the vent door through the chimney to go up inside of the coils to pull off the heat removed from the interior of the frig. I have almost 4" of open space between the coils and the outside wall of the coach. This lets most of the ambient temperature air flow outside of the coils and reduces the units ability to cool. This is not so much of a problem in regular weather but in high heat like we are having this summer, proper flow over the coils is critical. He said most RV manufacturers make this mistake and don't baffle the chimney area properly.
My plan is to buy a new thermister and to build a box out of aluminized insulation board that will take up the space between the coils and the outside wall of the coach forcing the air flow up through the inside of the coils and finned evaporator at the top. This will also prevent the heat on the outside wall from reaching the heat exchange portion of the unit.
Any observations or opinions will be greatly appreciated.
Kent, rather than an IR thermometer, which entails opening the door and perhaps skewing the results a bit if you're opening it several times to see if there's any change, I would suggest a wireless thermometer designed for this purpose. Amazon.com: Chaney Instrument 00985 Wireless Refrigerator Freezer Thermometer (http://www.amazon.com/Chaney-Instrument-00985-Refrigerator-Thermometer/dp/B000P55SN4) We purchased this unit (as have others) at the suggestion of Barry & Cindy, and I highly recommend it (less than $30). It has been great to keep an eye on what each side of the unit is doing - and it also displays "min" and "max," which I reset (one button push) each day to see what's happening in a 24-hr period. You can reset at any interval to follow the min/max, especially if you are making any changes. I also use a lithium battery (as recommended) in the freezer sensor. The display unit is small, and has a strong magnet - so I have it on the side of the microwave (and it never moves underway regardless of road vibration). Hope this helps.
Kent,
Yes, a good idea to verify that the refrigerator installation instructions, particularly about clearances are observed to the letter to insure most efficient cooling.
With your temperature swings, which sound to be based more on ambient temperature than any other factor, I would agree that maximizing refrigerator efficiency would be the first step. And, while in there eliminating any air space above or on the sides of the refrigerator, bringing back clearance to ideal spec, I would add two muffin fans at the top of the coils exhausting UP. You can put them on a separate switch or on a thermostat. They draw so little amps that they can safely be tied into the galley lighting/light switches.
Brett
The refrigerant in the absorber type refrigerator first flows into the freezer section and then to the coil in the refrigerator section. If it picks up enough heat in the freezer, there isn't any cooling capacity left for the refrigerator. At start up the freezer section will cool down first.
I think you found the problem with the gap between the wall and the heat exchanger. There should be a block of foam between the wall and heat exchanger to force the air through the heat exchanger. My coach has it, maybe yours fell out, someone removed it, or it wasn't installed to begin with. I'm sure FT is aware that it is required. My refrigerator installation instructions mention this requirement.
Pat: I also purchased the Chaney thermometer. it works very well. I use one in my home and in the rv. I velcrowed the unit to the front of the fridge in the motorhome as the magnets would not attach to the front of the fridge. It gives you a good idea at all times the temp without opening the doors. Another forum idea put to use. DAN
Kent you can buy a thermistor kit to splice into the old wire. I did this. Purchased from PPL and it took only a few minutes. If I had used the complete one the refer would had to have been pulled out to access the back.
I have made significant changes to the air flow behind the fridge, I have installed 2 Ultra muffin fans(1500 rpm, 52 cmf, dual ball bearing) connected to a thermodisc (stc-20) on the upper boiler pipe with the thermal paste, I have also installed a Thermistor Adjuster(Dinosaur Electronics) this will allow me to dial down the temp in the fridge in extremely hot weather(Note, on some of the new Dinosaur boards there is a pot that will do the same thing as the thermistor adjuster) I have also installed 3 (Koolink 80mm,1100 rpm,19cfm fans) Quietpcusa.com on the fins inside the fridge, I changed the light switch to SPDT switch, so when the door is open the fans go off, I will be adding an on off switch to control the fans in the winter months.
Pat, thanks for reminding me. I had two remote thermometers in the bay. They are not in the frig.
Brett, muffin fans are ordered and on the way.
Jerry, I guess it makes sense but with the freezer at 3 degrees I would think there would be enough excess cooling to cool the frig down below 59 degrees. Maybe not.
Barry B. also once mentioned a block of foam between the wall and heat exchanger. I want to make sure I understand. Is the heat exchanger the finned thing at the top of the stack or is it the entire system of coils and the finned unit? What kind of foam was used? Is it a special FR Foam? Many types of Styrofoam begin to melt at 140 degrees. I have measure temps at the top of the coils as high as 149 F. Do you know what the maximum temp of the unit gets up to?
If anyone can take a photo of a proper installation, I would be very grateful.
Jerry, I don't think I can use the kit because I damaged the thermister wire where it comes out of the wall when I used my test light probe trying to find a 12V source for the fin fan. Since you have already installed one, is that correct?
UPDATE: Outside temp is now 97 F. The inside temp of the frig on the bottom shelf is 38 degrees. The bottom shelf of freezer is 18 degress. The fins in the frig are 19 degrees and the shelf in the freezer is at 3 degrees. I don't believe I have a cooling unit problem. Now, to get the new thermister, due in tomorrow the muffin fans due in next week and figure out the best way to vent the heat exchanger.
following these Fridge cooler problems and read about the Chaney temp sensors that a few of you have bought and seem happy with, so I opened the link onto Amazon and have been reading ALL of the comments from buyers of this item. There seems to be an obvious problem with a lot of them as a large percentage have returned the item as inacurate or just plain does not work as it is supposed to. So what is the chance of getting a bad one delivered?? I would hope the manufacturer is working on the bugs it seems to have. Any comments from those of you that have them, re their accuracy??
Kent,
As the coach happens to be here at the house, I went out to check on what type of foam it was only to discover that I don't have a foam block!!! Takes a mirror and a light to see up behind the refrig and what I looked at before and thought was a foam block is the ceiling liner carpet, rather dirty and does look like a dirty piece of styrofoam. Yes that heat exchanger is the part right at the top of the refrigerator. On my coach it is located right under the roof vent. I removed the cover only to discover that many screws have to be removed to get in there. There is also a fairly large gap at the ends of the heat exchanger. I was all wrong about FT installing a foam block. Too bad about the thermistor wire, I have done things like that. There have been times where my freezer was cold but the refrig was not very cold, not like 59 though. I suppose anything like a piece of sheet metal or plywood would work as a baffle. Something that would not catch fire is best. Some folks have said that they lined the back of the refrigerator compartment with fire resistant material. I think it was Hardy board usually used behind tile in a bath or kitchen wall.
Hi, John. IMHO, it's like reading reviews for anything you order on Amazon (or elsewhere... or even reading RV park reviews on RV Park Reviews :: Home (http://www.rvparkreviews.com/))... take out the outliers to find the most useful information somewhere in between. One caveat with product reviews, I personally think, is that more
unsatisfied than satisfied customers will typically post reviews, often skewing a general impression of the product.
I've been pleased with the product thus far (had it for about a year). I will say that I have experienced the --E-- in the display on rare occasion (short-lived, though). With regard to the concern that the manual is incomplete, I've downloaded and attached it for your perusal. It appears to cover the general operation well enough.
I did find that when replacing the batteries, it seems to be similar to my Skyscan atomic clock (which has a remote thermometer sensor).... replace the
remote sensor batteries
first, and
then replace the display unit batteries. Even if you are replacing only one set of batteries (for example, only one remote), you should still take out and put back in the other batteries (ie, in the display unit). This is undocumented in the refrigerator/freezer product, but is documented in the atomic clock product manual.
Hope this helps with your decision.
Kent and others,
After getting some things out of the way, I looked through the installation instructions for my refrigerator. I have the Norcold 682, and I am sure it is the original one installed at the factory. According to the instructions, the ideal space behind the refrig is 0 to 1 inch. If there is more than 1" space, two baffles should be installed to prevent air bypass. One baffle is located at the heat exchanger at the top rear of the refrig, the other is at the absorber coils at the bottom rear of the refrig. The lower one would be just above the air supply opening. Baffles should be within 1/4" to the coils. I didn't measure but I have about 3" of space behind the refrig and no baffles. Really surprised that FT didn't comply with this requirement. The sides and top of the refrig should be sealed off from outside air which FT did do. My refrig has generally seemed to cool ok, but at times it has been warmer than desired. I thought that was just the nature of the beast. Would it perform better with baffles? I wonder if other coaches are like this? Could this be a reason for the cooling fans that so many have installed? If I install baffles, I would make them from sheet metal. I'm not sure why I thought that the baffle should be a block of foam. After thinking about it, foam would be a poor choice due to the heat. A better solution might be to build out the wall above the air supply door to fill in the space. I'm not eager to do that though. I suppose other models of absorber type refrigerators would have similar installation requirements. What do other owners have to say?
Jerry, what you describe is very similar to my situation. I have 4" clearance between the outside wall and the tubes and 3" between the outside wall and the heat exchanger. Today I installed two of the Valterra Fans designed for this use REFRIGERATOR FANS (http://www.valterra.com/rv/refrigerator_fans.htm) at the top of the stack. I had to remove the vent cover but installation was pretty easy. The fans come with two thermostats so they only go on when the coils are over 100 degrees and they go off when the temps go below 80 degrees. I used two separate toggle switch so I can better control when the fans are activated.
The fridge stayed cool all day with both fans installed. I had the remote thermometer on the bottom shelf near the door, the warmest place in the fridge. At 7:00 AM the temp was 46 degrees without any fans. The fans were functional at noon and at 5:00 PM the inside temp had gone up to only 48 degrees. The outside temp here was 103 at 5:00 PM and over 100 degrees all day long. On previous days with similar outdoor temps the fridge got up to over 60 degrees by 5:00 PM.
I am still going to install the proper baffles. I was going to use sheet metal but after careful inspection sheet metal baffles would be very hard to attach to the wall. I found a local source of flame retardant foam that is fabricating the baffles for me. The high density foam is very light weight, has a melting temperature of 180 degrees and is self extinguishing. I will pick up the baffles next week and don't know what they will cost. I will report any additional improvements once they are installed. I anticipate at least as much improvement with the baffles that I observed with the fans.
Kent,
As Steve will tell you, I tend to be the "food safety police" in our family. The safety zone for food storage is below 40 F or above 140 F if it's over 4 hours. And that's cumulative hours.
So target a few degrees below 40 as your sustained temperature.
Michelle
Kent,
I was getting the exact situation in a newly-installed Dometic this week. Sub-zero freezer, up to 68 refrigerator box, hot cooling unit.
Don't know how he did it, but the tech at the authorized Dometic dealer hard-wired the refrigerator to bypass thermister and all other controls. Coach plugged in to shoreline power. Ran it this way for 24 hours. No improvement. Diagnosis: blockage in cooling unit. A functioning cooling unit would have brought temps in bottom of refrigerator box to sub-freezing in just a few hours. New cooling unit on the way for installation next week.
Bob, thanks for the input but that's not what I wanted to hear. Please let us know if this is correct after you get the new cooling unit installed.
I spoke with David Force, the owner of RV Cooling Unit Warehouse for over 30 minutes. I have never talked with a more knowledgeable person on absorption refrigerators. He has been at this for over 40 years. After explaining the situation, rather than try to sell me a new cooling unit, he felt certain that by correcting the installation with baffling and adding the fans the problem would be corrected. He said when the outside temps are over 100, these types of refrigerators are hard pressed to maintain acceptable fridge temps even when everything is installed correctly and working properly. It is imperative that the back of the fridge gets maximum air flow.
By your description I think what the tech did was unplug the thermister causing the unit to run full out constantly. I did the same thing on mine but got the same result as when the thermister was plugged in and the unit set of the highest cooling level.
I will be very interested to hear if the new cooling unit makes a difference in your case. Please indicate what kind outside temperatures you are dealing with?
New refrigerator installed last day of March, when outside temp range was 35-40 nights, 45-50 days. Everything happy, with freezer sub-zero and refrigerator at 40 on the 4 setting. As daytime temps rose, so did internal temps of refrigerator, not by much, but enough to notice. Experimenting with auto/gas settings, thermistor positioning, and 3-4-5 settings had no detectible consequence, even when each adjustment had 12-24 hours to work.
As outside daytime temps rose, so did refrigerator internal temps. 70 degree days produced internal of around 50. 85 degree days produced internal of 60-65. Freezer remained subzero throughout.
When I took it to place where it was installed (Cummins Coach Care), tech was in touch with Dometic techs on line and by phone. One test was to remove thermistor, place it in ice-water, measure ohms. It was OK. Just for giggles, got another thermister, tested it OK, installed it. No impact on refregerator behavior.
Because of warrantee issues with new unit, needed to move to Dometic dealer for hard-wire test. Hard-wire test was more than simply pulling thermistor. Working from the outside, tech pulled some connections loose and made some new connections working with what looked like a small double-wire jumper cable, with connectors on all four ends. Bypassed everything. Control panel disabled. Plugged in refrigerator, run it wide open. Should have dropped internal temps big-time, pronto. No such result, even after 24 hours.
I'll let you know the rest of the story next week. And I will pursue the insulation question with them at that time.
Bob
Bob, thanks for the detail. It surely does sound like there is something amiss with your cooling unit. At those outside temps mine works perfectly. It only acts up when the temps go over 90, maybe 95, certainly 100 degrees.
Since I found out that I have too much space behind the refrig according to the installation instructions, decided to pull it out and have a look. I sawed the legs off a small table or platform that I already had so that it was the same height as the bottom of the refrig. Just slide it out onto the table. Wasn't hard to do, remove the doors, remove the screws on the front trim strip, a couple of bolts in the back on the floor or shelf that it sits on, disconnect the propane line, and electrical cables, then wiggle it out. Found that FT lined the sides of the cabinet with blue foam. Helps keep the refrig cool. In the rear lower corners they also installed a thin piece of gel coated fiberglass. At the top of the burner chimney the heat had melted the foam a little bit. Don't know how close it was to catching fire or if the foam is flammable. It looks like the same stuff you can buy at Lowes or Home Depot that has flammable printed on every sheet. The outside of the refrig that you do not see is covered with a tar paper like material that has a silver metallic coating on the outside. The piece covering the back had curled up along the edges where it wasn't held in place by sheet metal, mainly at the bottom where the control boards, propane valve, and burner are located. Where it is curled up there is a gap in the insulation, on the left side looking at the back there are control wires in the gap. The curled up part is stiff and brittle. I think it could be repaired by trimming off the curl, squirt some foam in the gap, trim it flat after it hardens, and cover with a piece of duct tape or metal tape. However, this refrig is 15 yrs old and I have decided to just replace it with a new one before it quits while I am on a trip. I have a Norcold 682 and the replacement is supposed to be N841 and have the same dimensions. PPL has them for $1090, CW $1530. I'm driving to Houston Wed. in the minivan to pick it up, cheaper than getting it shipped if you don't figure the true cost of driving. I may have to buy some door panels. I have decided that the easiest way to get the right clearance behind the refrig is to install some strips of wood and fasten a piece of sheet metal the width of the compartment from the ceiling to just above the air supply door. I may put some insulation behind the sheet metal. I also found that there was about a 1" gap between the ceiling and the top rear of the refrig, may close that off too so that hot air does not get in the space above the refrig. There was a piece of foam under the front trim that acts as a seal. It has fallen apart.
Now I have to figure out how to get the old one out and the new one in. Looks like the easiest way is to remove the entire window frame over the dining table across from the kitchen stove and counter. The smallest dimension is about 24.5" front to back with doors removed and the glass part of the window is that tall or a little more so the opening is even larger. I don't think it will go out the front door as maximum width is 24" and even with the door removed some of the hinge may be still there. Anyone know for sure if removing the window will or will not work? This is a 96 U270 with the kitchen on the drivers side. Thanks.
Jerry, Don't know if the dimensions are the same but CW took mine out thru the right front window. Mine is a GV.
CAUTION, CW screwed up the plastic trim on the window as they scraped it and broke the edges off with the reefer going in or out.
I DO NOT RECOMMEND CW FOR ANY INSTALLATION WORK OF ANY KIND.
Sorry to shout so loud.
Gary B
Sounds like we have the same floor plan and recently took our Norcold 682 out through the curbside window by our Stressless recliner where we can get our body closer to the window. Seemed better than working over the kitchen table, which we did not want to stress. A forklift was used to carry the fridge out on its side with doors still attached. We have a finished wood wall right next to our fridge hinges, so we taped up a large piece of cardboard to protect the wood.
If your window still has 'runny' gray putty, after it removed, clean off the putty and then use the new 'D' weathers-trip-like new windows are using. Xtreme Graphics in Nacogdoches will sell you some. Motion Windows has instructions on window removal and re-installation.
www.motionwindows.com/installation-guide.pdf (http://www.motionwindows.com/installation-guide.pdf) a
Our Norcold fridg also was original and working just fine.
Additional insulation is always a good idea.
Barry & Cindy
Every summer that I go out and the temperature gets above 100 degrees I have the same problem as you.
This year I left earlier and the temps were not as severe yet and the fridge worked fine.
Then on the way home I hit 110 degrees in Holbrook & Needles CA. and up went the refer temp to over 50 degrees.
I did check to see if I had that foam on the wall behind refer & I do. I never noticed it before.
But there is a gap on one side of refer and wall that is not filled in but I dont see a way to get a piece of foam in there from bottom or top.
I dont think the refer can compensate for pulling in 100 degree outside air even with the fans working.
I have already replaced the cooling unit last year.
We did notice that when my wife put some frozen food in the refer to thaw that the temp did go down.
I wont get a chance until next year but I was thinking of having a couple of "non-toxic gel Freezer Ice Packs" to rotate from the freezer and see if that might be enough to keep it near temperature.
If you are still in that heat give it a try and tell us if it works.
The other think I was thinking of was putting an awning over the refer vent as much as I would not like one there or a makeshift cover that still allows the air from underneath.
Barry,
Now that we're across and in a site with the afternoon sun hitting the fridge, I noticed the sound of a fan running behind our fridge. Steve reminded me that we have one - it got bumped during the icemaker line replacement.
I looked in all our paperwork and the manual for the NDR-1492 and see no mention of one. Do you have such a fan? I'm wondering in the original owner of our coach added it at some point in the year he had it.
Michelle
i do have double fans that were reinstalled when they put in my new cooling unit.
Photos here will show where they are installed.
Replacing Refrigerator Cooling Unit (http://beamalarm.com/Documents/replacing_refrigerator_cooling_unit.html)
Barry: Sounds like a great idea with the blue ice or gel packs. I plan to carry some of these in my freezer in my storage bay. If the heat brings my temp up in the fridge I can move some of these over there. Great idea. I also got a couple of the small battery operated fans to help also during these hot days. Tks Dan Stansel 02/40/U295
I hate to throw a wet blanket on the gel packs but we tried adding ice to the fridge. No help. We are still very much in the heat, 103 today. However, I have found a fix. I installed two of the Valterra Fridge fans setting right on top of the heat exchanger. My Fridge temps have been 33 degrees up on the top of the fridge fins and 46 on the bottom of the fridge section near the door, the warmest part of the fridge. Everything above that spot seems to be cool enough even in the late afternoon. The fridge side of the coach is facing north so it is not getting direct sunlight at that time.
I also have purchased flame retardant foam and made a baffle to force the air through the fins on the heat exchanger. My hope is that I won't need to use the fans that often but my experience this afternoon was a bit of a shock. With the baffle installed, the fridge actually got warmer than the last few days with just the fans running. One day does not give me enough experience to make a final judgement, but I now will need to test the baffles more thoroughly before I install them permanently. I won't be able to test the baffles further until next week. The coach goes into the shop tomorrow and Friday to get the new bedroom A/C installed.
Once I finalize my Fridge Fixes for hot weather use, I will do a complete write up on my experiences and hopefully some photos.
For those of us dealing with older refrigerators, don't overlook the gaskets on the doors. New gaskets won't solve the kinds of problems being discussed here, but they will help keep cold air inside and warm air out.
I thought I should add, the Valterra fans cost about $32, but they are housed in a 4" air tube to improve flow and they come with two automatic thermostats so they can be set up to work automatically. I installed mine with manual switches but these fans are less expensive than good quality muffin fans plus the cost of an automatic switch.
I bought one from Amazon and the other from a local RV dealer. I won't buy another one from Amazon. I paid $32 for second day delivery and the Amazon dealer took 4 days before they shipped it. Total cost $62 vs $32 at the local store. Camping World no longer carries these fans.
Kent,
I would be curious as to how much of a difference there is when the fridge side is facing the sun & when it is not. If there is any chance of keeping it cool enough when facing the sun side with plus 100 degrees. I dont think there is. I want to see if I need to be concentrating on an awning of some kind.
Not knowing anything about these fridges; I assume the Valterra fan goes outside behind the vented cover. I was looking for install instructions. Where is this posted? Tks DAn Stansel
We need to remember in much of the US, on June 21st the sun rises as far north of east and sets as far north of west, and is overhead at mid day. Thinking the north side of a coach is shaded is most likely wrong. Think NE and NW.
In the winter the sun will rise and set 90 degrees further south as in SE and SW.
I sell windows and so few people understand compass directions and the differences for sun exposure on their home thru the year. They want north facing skylights, which will overheat all summer.
Shading the refer. wall has to help I would think, as would shading the coach as much as possible.
When I was getting my U225 from Kent last April, his refer. side was on the south side, coach facing west.
Dave, you are way too observant. I have turned the coach around so that I don't get afternoon sun on the front of the coach. I do not get direct sun on the side of the coach in the afternoon but its close.
Barry, my guess is that there is ample insulation to allow increased air flow to offset the heat of the afternoon sun but I'm not sure.
Dan, I just removed the vent cap on the roof of the coach. You will need new 1" putty caulk strip to reattach the vent cap and be sure not to over tighten the screws when reattaching or you will crack the vent cap base. With the cap off, I made L brackets with plumbers strap which comes with the fans. I then drilled small pilot holes then screwed the bracket into the sides of the vent hole. The vent hole is lined with aluminum and a pilot hole must be drilled. The base of my fans are about 1/4" above the fins on the heat exchanger thereby pulling air through the fins. I used two fans but there is room for three. I got my power from a blue 12V wire near the bottom of the refrigerator closet. I stripped the insulation from the wire in a small area with an Exacto knife and soldered a 10 amp, fused 14 gauge wire to the hot 12V wire. I hooked the wires from the fans to the fused hot wire with red butt connectors. Actually, I installed on/off toggle switches to allow me to turn the fans off but that is not required. The fans come with automatic thermal switches that should adequately control when the fans run. I just wanted manual control.
I will give a more detailed explanation of the process once I finalize what is going to work. I'm still playing with baffles to help reduce the use of the fans and I may incorporate the thermal switches when all is said and done.
Bill,
Thanks for the email. Good idea. So, for those with hot weather fridge problems, Bill's idea is to take a couple short lengths of flex ducting and perhaps go down below the fridge into the vacuum compartment (at least that is what it is on mine), put in a couple of inline 12v fans and take the much cooler air out of the coach (that has the forward air on) and push it up behind the fridge. Would not need it at night. On mine, it would only require the lower vacuum door to be open. Probably would be enough cool air so the excess would just go out the normal exterior fridge intake with the rest doing its job on the condenser. The coolest air should be right on the floor just waiting to be used.
I do have a layer of Hardy Backerboard against all sides and roof in the fridge compartment and have had no problems with cooling so far. Thinking back, I have had the entry side exposed to the sun so it may be a problem if the sun were to be on that side.
I do have enough room with my Norcold so I could pull the backerboard off and put a layer of silver backed rigid foam in for a little more insulation from direct sun and then pop the board back in to make it fireproof.
I have a Mac tower in front of me with 7 fans. As it gets hotter, more fans at higher speeds come into play until it sounds like a jet taking off (well almost) so the fan idea sound good (so to speak).
I can see it in my head. Ideas/comments from others? Did I miss anything Bill?
Back to the floor sander for the rest of the day :(
Pierce,
as I see it, the fans below on the coils only force the already heated air faster across the coils. Giving very little cooling effect.
I hope some of the engineers here will comment on that before I start the project.
Bill,
As I see it, we have radiation, convection and conduction here. The sun beats on the side of the coach, radiates heat into the fridge compartment and onto the back of the fridge itself. Some of the heat is also transfered by conduction from the hot air in the space into the fridge itself. The cool air in your idea would displace the hot air and force it out the top so we are taking a percentage of conduction heating and also mitigating the effects of radiation through the side of the coach. Yes?
My idea of flat white paint on the side of the coach probably won't get many votes. ;)
I look at it a different way, with the outside temp at 103 degrees and the heat exchanger at 135 degrees, the fans are removing 32 degrees of excess heat, allowing the unit to cool better.
Bill,
Yes, but quite a bit of that 103+ heat behind the fridge is soaking through the back & side insulation (in a very large area) and defeating the relatively small area of the evaporators. If the condenser were remotely mounted, that would be exactly true but when you add that heat (the 135 degrees) along with the ambient, I think it is more that the insulation on the back of the fridge can handle and still keep acceptable interior temps. Plus, nothing is sealing off the sides of the fridge so that adds to a larger difference between the interior and exterior temps of the unit on almost all sides except the front. Isolate the fridge better and you are exactly right.
Bill,
would not the 85 degree temp cool the coils a tiny bit more than the 103 degree's. To some where between ice cold winter and spring and fall?
Remember, its temp differential plus air flow rate. If you increase the air flow you will carry away more heat per minute. Natural convection is probably 1-2 CFM, 5 tops. A 20-30 CFM flow rate increase will go a long way against any heat soak.
I installed an on off switch just for that occasion.
Just a couple of thoughts after reading all the posts: Doesn't evaporation cool? We used to wrap our beer in wet towels and let the wind pass over. Colder than a fridge! Any way to incorporate this principle?
Second, in the Mideast the use of fretwork on buildings caused air to compress when entering (LOSING HEAT) and expand when leaving the building (TAKING HEAT).
This was a very
passive way to "air condition" buildings.
Kent -
Here's the follow-up on my experience with a replacement cooling unit you asked for.
New replacement cooling unit installed (warranty work) on new Dometic 52 hours ago. Current data: Freezer 0, Refrigerator 32, and holding steady. Thermistor centered on far right fin. Controls set at 3 on Auto-Electric. No added insulation to fill spaces, no fans. Cooling Unit is no longer almost too hot to touch. It's warm, but easy to handle, and cooler as I reach higher. Daytime ambient temp is 85, nightime around 50.
Hope this helps in some way.
Kent,
It would seem to me that Bob Mulder has the solution,
"Daytime ambient temp is 85, nightime around 50."
You just need to relocate you, Peggy, Trip and the coach to his area, and I need to follow your lead. Think we are getting all the way down to 79 tonight, and then back up to 100 tomorrow.
Yessir. We are looking at up to 5 summerish months in the northwest, about 3 winterish months along the Colorado River at Lake Havasu in Arizona, and 2 months or more for taking really long or really slow or really crooked routes in each direction. Not a bad life. Especially in our FT. Even at the current cost of 50 cents per mile for fuel. We live generally between 45 and 85 degrees year round. Agenda is driven substantially by our desire to avoid dramatic seasonal swings in temperature/humidity that seem to correlate with swings in a certain medical condition. Helps that we enjoy the weather, and enjoy the people, in each place.
And I hated not having confidence in my refrigerator. Tossed-out contents 3 times since March during this fiasco. I'm keeping all suggestions about fans and insulation in mind, and will likely still "upgrade" with them, even for moderate ambient temps we usually encounter over the course of a year. Appreciated this timely discussion.
Most folks who visit this area summer/fall seem to like it. Hope you can give it shot sometime.
Bob, thanks for the update. This morning it is 78 degrees at 7:00 AM. Freezer is -4 top shelf, fridge is 24 on top of fins and 36 degrees on the middle shelf. Fridge setting is on 4. This is after installing the two Valterra fans on top of the heat exchanger just under the roof vent, no baffles yet. I also installed the small ebay fridge fan in the interior at the top of the fins.
During the hottest part of the day, 104 yesterday the fridge got up to 42 degrees on the middle shelf and 35 on top of the fins. Freezer never gets over 3 degrees on top shelf. For some reason everything seems to be working better since I took the coach to the RV dealer. I am guessing the bumps encountered on our wonderful Oklahoma roads burped the absorption system a little bit to make it work better.
I still plan to test the baffles next week to see if I can get cooling improvement with a passive baffle system rather than the 12V powered fans.
Then you need to take it on a drive down I-10 from Baton Rouge to Louisiana - it would be like new!
Try US-69 through eastern Oklahoma. That will shake up everything in the coach. To provide a more serious "burping" of the 'fridge would require tumbling it. US-69 is worse than I-40 on the west side of OKC. I was astounded that they could build a relatively new road to be so rough.
The exception is the portion between Texas and the casino near Durant. It's smooth as can be. It provides a smooth ride for Texans to bring their money to the casino.
We tried the route between Kansas City and Bellville via US-69 once. We will only try that again if the memory fades.
JD, we work very hard at making a new road feel old. We call that the Oklahoma standard for road construction. The Oklahoma Standard for Disaster Response is world class. The Oklahoma standard for road construction is low class.
You guys have never been to California. We just don't do road construction. If you were on a commercial flight, they would collect all the meal trays and everyone would bring out their rosary beads. We watched the movie 2012 but thought it was like an everyday drive here.
Hey Kent, I think I just found the cause of your fridge malfunction. I touched the white, west side of our coach at 6:30 tonite (air temp 84 degrees) direct sunlight from 1:00 PM on. I could keep my hand on it, just slightly warm. I then touched the painted on burgandy graphics--almost blistered my hand. So I can just imagine what your black painted coach side would feel like in the Texas heat and sun!! Seems like some kind of reflector/deflector is needed if you can't keep the back side of the refrig out of the sun. Why not some kind of roll-up white or aluminum painted shade that would hook over the fridge top vent and then down the coach side?
I agree with you as far as shading that vent opening when in direct sun. I dont think the refer can compensate for that 110 degrees coming in the vent. But dont cover the vent with the shade as my experiment shows below. You need that air not to be blocked. I am trying to come up with a angled shade to cover it so air still comes in the bottom. I tried an aluminum sunshade with snaps but in Needles the wind was to high to keep it in place. I need something more solid that can fold up when not in use. Still experimenting. ::)
Certainly direct sun exacerbates the cooing problems but in my case that side of my coach is not exposed to direct sun in the afternoon. My problem was air flow through the fins of the heat exchanger. Right now we are still in 100+ temps in the afternoon but the fridge is staying cool with the assistance of the two Valterra Fridge fans. Its working great now. I will let you know what happens with direct sunlight when we get back on the road.
In the parking lot at Nac ... having a very hard time getting the fridge to go below 50 after it was shut down for an extended period of time while the icemaker was repaired and made operational in the freezer. We finally extended the large awning to provide shade for most of the day and found room in the outside fridge access compartment to plug in my little bitty $5 Walmart fan. Once it got the added benefit of a full night of 80 degree temps, it has not risen about 40 degrees. Yay!!
Carol, one of the tips I have picked up during this discussion is to put a bag or two of ice in the fridge to help it with its initial cool down.
Kent,
That works well. We go shopping in Sac a lot and carry a cooler in the car with a big bag of ice in it for the cold stuff we get a the discounters. I just put it in the freezer at home and when we start a trip, put part of it in the RV freezer with some in the fridge. It seems to take at least a couple of hours for the RV fridge to get down to safe food temps and the ice really helps speed the process. Left over cubes come in handy also.
As a recap, we have had 100+ temperatures here in Oklahoma for most of June and now all of July. My refrigerator was getting up to 60 degrees in the late afternoon due to the high outside temperatures. The final chapter in this lengthy thread is now closed. It is 5:00 PM and the outside temperature is 106. The refrigerator is 38 degrees. The answer is two Valterra Fridge fans and a foam baffle that directs the air through the fins of the heat exchanger/condenser. The fans are on individual switches so I can use one or two as the temperature demands or no fans most of the time.
Here is a link to one source of the Valterra fans: Valterra A10-2618VP Universal Mount Vent Fan 12 Volt Camper Trailer RV (http://www.americanrvcompany.com/Valterra-A10-2618VP-Universal-Mount-Vent-Fan-12-Volt-Camper-Trailer-RV_p_8576.html) or you can find them a many major RV Stores, but not Camping World.
The foam I used is a self extinguishing, Flame Retardant Styrofoam with a 180 degree melting point. I purchased a 4" X 36" X 3 1/2" block from Taylor Foam: Taylor Foam Inc.- Contact Information (http://www.taylorfoam.com/taylorfoam_com/contactinformation/) for $22.00. I had to cut the block in two pieces to get it up in the stack area behind the fridge. I also cut a 45 degree angle on the bottom of the blocks so they were beveled. The bevel should slightly improve the air flow up to the fins. I then glued the foam to the wall of the coach with a non-solvent caulk adhesive where the top edge of the foam was just below the lowest point on the fins so that air coming up through the stack was directed toward the fins. The baffle gave me an additional 9 degrees of additional cooling vs the fans without the baffle. I presume the baffle will also allow me to run the fridge without the fans at much higher outside temperatures than before. Remember, I originally had 4" of clearance between the outside wall of the coach and condenser that allowed most of the air coming in the door louvers on the back up to the fridge stack to flow around the condenser and out the fridge vent on the roof. These refrigerators are designed to have 1/2" clearance which forces the air flow through the condenser.
that's my story and I'm sticking to it. I hope it helps others who have problems keeping their fridge cool in this incredible heat.
Kent I know there has been some of these fan pictures shown but could you post some of your
set up. Are the fans installed under the roof vent cover or the side cover on the coach.
Dan Stansel
I knew that question was coming. I finished up at 10:00 AM this morning and it was 105 on the roof so I took some not so good photos. I will post the only decent one showing 1 1/2 of the fans to give you and idea, but to go back up and take better pictures means removing the roof vent and ruining the caulk around the base of the vent. Sooo, that ain't gonna happen. I hope this one photo helps. This photo is with the roof vent removed straight down at the fridge vent hole. The condenser is offset toward the rear which also reduces conductive flow and should not have been done originally. However, there is still room for three fans if it were necessary.
Follow up to my previous post in this thread. Installed the new refrigerator and it worked. Replaced the Norcold 682 with a Norcold N841. Removed the window at the kitchen table to get the old one out and the new one in. Storage yard owner backed his flat bed truck up to the window so a couple of helpers could stand outside the window. Removed the refrig doors and they went in and out with the door opening down. Not very hard at all, nothing got scratched up. Had a furniture blanket on the window opening and table. I didn't have to do any trimming of the cabinet opening to get the new one it. It fit perfectly.
After removing the old refrigerator, I was somewhat appalled that Foretravel did not follow the installation instructions for the old refrig . Usually they are very good about that sort of thing. The area above the refrigerator was not blocked off and there was too much space behind the refrigerator. Apparently that is important as the airflow in at the bottom and out at the top works somewhat like a chimney does. Before I picked up the new one, I built a baffle wall to reduce the space behind the refrig. Just a couple of pieces of wood fastened to the wall with screws and piece of thin aluminum sheet metal fastened to the wood. I did put some fiberglass insulation behind the aluminum. Stapled some insulation to the ceiling above the refrig and added a piece of aluminum to block off that area. The ideal installation seems to have the refrig as close to the back wall as possible without touching it. Up to 1" space is okay; 1 - 2" add a couple of baffles; more than 2" build a baffle wall. The old instructions do not mention a baffle wall, but the new instructions do. Foretravel insulated the sides of the cabinet, a good thing, also the fit is very close on the sides which is good. I added some metal on the side wall near the burner exhaust where the foam was melted. It doesn't extend along the side of the refrig though as that would transfer heat into that area. The trim around the front of the new refrig is not quite as wide as the old trim. The wood outside the old trim is darker than what was under the old trim. Didn't look good, so masked off a small strip down the sides and painted it black. Needless to say both the old and new refrigerators went in and out of the cabinet several times, before everything was correct. This would have been a real problem without the little table level with the bottom of the opening.
Started the refrig at 10:30 am with the temp setting at 5 (range 1-9), shut off the generator and air conditioning and went home. Returned at 7 pm 8 1/2 hours later; coach interior 106 F, outside 99 F, Freezer 0 F, Refrig 39 F. At 10:30 am the next morning coach interior 91 F, outside 87 F, freezer -2 F, refrig 37 F. I think it is working okay. I have no fans, but nothing was in the refrigerator and the doors stayed closed. The temperature shot up to about 50 F in the refrig shortly after opening the door.
There are some differences between the old and new. Some of the plumbing on the back is different but the major parts are in the same places. An overheat sensor has been added near the burner area. There is supposed to be an audible alarm for door open, no flame, no ac, etc I haven't heard it, but the visual indications work as advertised. The manuals are rather hard to use, all the illustrations are on the last pages after the french section. The wiring diagrams have lots of numbers and letters that have to be looked up in the middle of the book. Finally printed out that page from the website to make it easier. Norcold does have a manuals section on their website.
Inserts for the door are purchased separately and the old ones are not wide enough for the new doors. I made my own from 1/4" oak plywood which is 7/32" thick, still too thick as 3/16" is specified as the correct thickness for an insert. Plywood will work though if the edge thickness is reduced with a belt sander on the back side. There is still space between the panel and the door in the middle area. I choose plywood over plastic as it is has slightly better insulating qualities. Sealed both sides with 2 coats of thin dewaxed shellac and 3 coats of Miniwax satin finish polyurethane on the good side. Light sanding between coats. Shellac is not water resistant, but it does slow down the movement of moisture in and out of the wood. The color match with what is in the coach is very close.
Kent and Jerry,
You two guys have shown a lot of initiative and creativity to solve a serious problem. Jobs well done. Good pics, Jerry.
Jerry, nice job. I'm just glad I did not have to go through all you did. My tiny job was bad enough in this heat.
Jerry, Good job installing the reefer, one h... of a better installation than CW did on mine.
One question, How did you handle the drain line. On mine they wanted to lead it thru the louvers on the outside access panel. I cut the drain line off and ran the line into an old plastic coke bottle that I only have to empty every couple of weeks depending on humidity etc.
Now go get that cold one out of the box and sit under the awning and enjoy it.
Gary B
I didn't have to do anything with it. You can see it in one of the pictures, a white tube, empties into a plastic box where the water evaporates. The old one was the same except the box was aluminum. I need to quit working on it and go somewhere. I think I have a buyer for the old one, if not bulky trash pickup later this month.
We're currently in Tucson where temps have been in the low 100s daily. This is our first experience with really hot weather and last night I noticed that our refrigerator/freezer (Dometic) was unusually warm (49/9). So today I installed two fans on the heat exchanger using Kent Spears post as a guide. I did a couple of things differently. First, the foam to direct the air through the heat exchanger was already there so I didn't have to put that in. Also I used a fused 12v wire running to the ice maker as a source of power. And finally, I did not put a switch on the fans, but left the thermal switch that turns them on at 100 degrees. I was amazed how hot that exchanger was! I think the fans will be on most of time. Attached are a couple of pics of the project. The fans seems to help. The temps are now down to 38/4 which is fine. The outside temp is about the same as it was yesterday.... 100+. Again, the forum has been a big help. Special thanks to Kent!
Update.... I decided to add a switch for each motor. That way I can tell if each is still running. It is impossible to see the fans once the vent is in place. See the attached photo.
Here is another thing I am trying to reduce the temp of the refrigerator compartment. The newly installed fans continue to work well, but as I said in the previous post, that heat exchanger for the refrigerator is HOT. And the air path, at least in our coach, to bring air up through the exchanger is torturous at best. Barry tried a shade to cool the outside of the refrigerator with some success (see his previous post), but I got to thinking that just opening up the refrigerator cover would provide both some shade for the refrigerator and provide a path for more cooling air to enter the compartment. See my first attempt at this arrangement below. Any thoughts? Has anyone tried this? Problems? I do plan to close it when we are gone and at night. This would just be for the hottest days when we are in the coach.
I just replaced a cooling unit in a Allegro Bus, and Dometic Had me install a 105 degree thermostat , It came standard with a 140 degree thermostat. Also they had me install a second fan, And check the spaces from the sides and to the back, they say 1 to a max of 1 1/2 inched to the back wall . It should have foam or something sealing it up on top and on the sides. Art
It's a good thing the heat exchanger at the top of the refrigerator is hot, otherwise it would not be cooling the inside of the refrig. Some of that heat is added by the burner or electric heating element. It's what causes the coolant to circulate. That heat and heat from inside the refrig is dumped back into the air by the heat exchanger. When I replaced my refrig recently, I prepared the compartment as instructed by Norcold. There was several inches of space in the back of the compartment behind the coils and piping. I added a baffle to in effect bring the wall closer to the back of the refrigerator. That forces the air to move over the lower coils and piping, and through the upper heat exchanger. I put insulation between the baffle and outside wall and above the refrigerator. It is difficult to tell if the new refrig cools better than the old refrig. The new one was okay on a recent trip with 5 people and some high temperatures in Texas. The hard part was convincing my son-in-law not to open the door everytime he walked by. It would warm up inside the refrig from that. My coach is mostly white on the outside. The newer darker paint jobs look good, but the solar heat gain must be increased due to the darker colors. Doubt if opening the lower vent door helps very much, might even hinder if the sun angle is more direct.
I think mine is built in the same way, i.e. the space between the outside coach wall and the heat exchanger is filled with "blue" insulation board. I agree, the exchanger should be hot (it is moving heat from the refrigerator to the outside atmosphere), but is there a danger in cooling it too much? In looking at the temps from the freezer/refrigerator before and after propping open the cover, it is hard to see any effect, positive or negative.