Barthmobile Portal
clarification

This topic can be found at:
https://www.barthmobile.com/eve/forums/a/tpc/f/9331087061/m/7553997097

12-08-2017, 04:49 PM
Duane88
clarification
I could run the fridge on propane, but it needs some work to function properly works well on 110 volt element.

Yes, my coach batteries are deep cycle.


1971 24 ft Barth Continental
P30 chassis
350 engine
12-08-2017, 07:36 PM
Kevin
Keep the Stack clean and painted on the refrigerator. You do not want the coils rusting. Also be sure to have the coach level if using propane.
12-08-2017, 10:37 PM
Duane88
Hey Kevin good points, the ammonia, water mixture used in the absorption process has some corrosion preventatives, but usually corrodes inside out in about 10 years. My unit is original so it is 30+ years old but the tubing is still pretty solid not sure why, but happy about it.

The ignition system and auto pilot system are my problem. They have been broken for awhile, when I run it on propane, I have to turn the temperature as cold as possible so it never shuts the flame off, I also have to hand light it, by taking the inspection cover on the stack off. Just need to find the old parts I need somewhere.


1971 24 ft Barth Continental
P30 chassis
350 engine
12-09-2017, 02:43 PM
Gary Carter
If you try to run you fridge on AC from your invertor you will have a dead battery quickly. The fridge will pull close to 1000 watts. Anything with a heating element will draw big watts.


'92 Barth Breakaway - 30'
5.9 Cummins (6B) 300+ HP
2000 Allison
Front entrance
12-12-2017, 01:16 PM
L78steve
quote:
Originally posted by Gary Carter:
If you try to run you fridge on AC from your invertor you will have a dead battery quickly. The fridge will pull close to 1000 watts. Anything with a heating element will draw big watts.


I run the fridge on the inverter only when on the road (engine running).
I have problems with the gas flame blowing out when on the road.



1993 34 Regency WB
8.3 Cummins 300HP
12-14-2017, 12:22 AM
Kevin
Probably the best option is DC on the highway. If I run the refrigerator at night and the running lights, along with heat, (dash heater requires the vacuum pump and runs a blower) the alternator just is just a few amps of keeping the battery fully charged.
Steve you may have a flame adjustment on your refrigerator when using propane. My refrigerator has a flame adjustment. When the flame is adjusted too low it goes out, or will not keep the food below 45 degrees. Shore power for the refrigerator is best if you can plug in. Works with the generator also.
12-14-2017, 06:38 AM
Steve VW
quote:
Originally posted by Gary Carter:
If you try to run you fridge on AC from your invertor you will have a dead battery quickly. The fridge will pull close to 1000 watts. Anything with a heating element will draw big watts.


Actually, most of the electric elements I have seen were 200-350 watts. (That is still about 25 amps on 12V)

https://www.amazon.com/Dometic...lement/dp/B00PWKWS08

http://www.adventurerv.net/nor...c&utm_source=Froogle

I think the small element is why the frig works better on gas. Mine will cool quicker and colder on gas than propane.

The older units had a thermostat that changed the flame from a low flame setting to higher flame and the burner ran all the time, just flip flopped between flame sizes depending on demand.

My father bought a new frig for his boat and it has a different setup. The flame is one size only and cuts on and off as needed. So far we have found this one to be less effective on gas than electric.

Be sure to clean the flue and set the burner correctly. Be sure the venting and compartment are set up properly too. I have several gas frig and the flames have never gone out.


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
12-14-2017, 07:30 AM
Pirate19
My apologies for contributing to the drift. Kevin, please feel free to manage my post.

"Keep the Stack clean and painted on the refrigerator. You do not want the coils rusting. Also be sure to have the coach level if using propane."

Kevin, do you believe a fridge operated on electric (12V or shore power), as opposed to propane, has a higher tolerance for being out of level?

Secondly, has anyone had any experience with fans installed to increase the efficiency of a fridge?

https://www.amazon.com/Triple-...300_QL70_&dpSrc=srch

https://rvcoolingunit.com/Dome...iring--P3261872.aspx


'92 Breakaway
Cummins 190hp, No Modifications
Allison AT542
Floor Plan 30-BS-11B
9205-3798-30BS11B
12-14-2017, 07:33 AM
Steve VW
Dad put 2 small 12v muffin fans in the frig compartment in his boat when he installed the new frig. Made a big difference. Freezer was about 15 degrees colder. It improved cooling with both electric and propane.


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
12-14-2017, 08:51 AM
L78steve
quote:
Originally posted by Kevin:
Probably the best option is DC on the highway. If I run the refrigerator at night and the running lights, along with heat, (dash heater requires the vacuum pump and runs a blower) the alternator just is just a few amps of keeping the battery fully charged.
Steve you may have a flame adjustment on your refrigerator when using propane. My refrigerator has a flame adjustment. When the flame is adjusted too low it goes out, or will not keep the food below 45 degrees. Shore power for the refrigerator is best if you can plug in. Works with the generator also.


On the Dometic side by side I don't see any flame adjustment.
And no DC option on this one. I made a baffle for the flame we'll see if that works. But an Exeltec inverter is in the works for the 93 Regency.



1993 34 Regency WB
8.3 Cummins 300HP
12-14-2017, 09:02 AM
Kevin
quote:
Originally posted by Pgh. Pirate:
My apologies for contributing to the drift. Kevin, please feel free to manage my post.
Ted, you need to be responsible for your own actions. Hide
quote:
Originally posted by Pgh. Pirate:

Kevin, do you believe a fridge operated on electric (12V or shore power), as opposed to propane, has a higher tolerance for being out of level?
I was told, flame burning against the coil could burn a hole in the system. Being occasionally being not level while driving mostly not a problem. Parking on a slope and using the propane refrigerator on LP could be a disaster.
quote:
Originally posted by Pgh. Pirate:
Secondly, has anyone had any experience with fans installed to increase the efficiency of a fridge?
Fan in the refrigerator? At home the beer was almost 50 and gave too much head with every glass. The fan motor had seized up and needed oiled. After lubrication my beer was down to my standard 30.5 degrees. So a fan should improve your motor home fridge. I think one would be adequate. Only one fan is all that is in the refrigerator at home. Here is a fan on eBay.
12-14-2017, 10:52 AM
Duane88
Back in the olden days, lets say before 1995. Both Dometic and Norcold made refrigerators with lots of options for control of the absorption system. Your choice between an electronic system, or a manual system. The manual systems had a valve with a two stage burner control, higher flame to cool the system, lower as a pilot. On smaller units lets say 4 cubic foot, the Norcold manual unit would actually freeze food in the fridge when the pilot was in use. NSF requires all fridges to keep cool to 40F in a 90f ambient. With the manual systems, one could option up to 110 volt A/C and/or a 12 D/C system.

The electronic systems had similar systems for the electric side, except it was all done by the selection switch. The propane side had an electronic spark pilot system similar to those used in your home gas water heater or boiler.

Regarding the off level operation of a propane absorption system. The system is all gravity feed of the ammonia, so if it is not some what level it can not flow through the feed tube properly and cooling can be stopped or slowed.

The lower serpentine tubing that is mostly visible from the back side of the fridge is mostly liquid ammonia and water. So if the unit is not level and the ammonia is not flowing as it is separated from the water prior to being condensed above the heat stack and the area around the flame becomes only gas it might start to corrode from the inside out, the system rust preventives are not in contact with the burner tube, rare and extreme but I guess it has happened.


1971 24 ft Barth Continental
P30 chassis
350 engine
12-14-2017, 11:56 AM
Jim and Tere
I know you guys have covered everything refrigerator here but a source for repair or even more info that we have dealt with for Rv fridge repair in this post.

Talk to Sam Obermiller owner, expert:

R V & Camper Refrigeration, 5808 Stockbridge Dr. Monroe, NC 28110
704-821-9119

He rebuilds rv fridges. Does something that makes them better than new. I think he charged us around $700-800 on old Blue. That was several years ago. He can at least guide you to what to ask repair person in your area. You can say Jim & I suggested you contact him. He went to school with our kids. FYI He does not haggle on price. It is what it is.

Tere


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
12-14-2017, 12:25 PM
Gary Carter
Ok, I was a little high on my estimate of ac usage in an 8 cu ft dometic. They list the new one at 325 watts. Still a good chunk of ac.

As to level, it makes no difference what the heat source is. The same cooling unit is used and only the heat source to boil the ammonia refrigerant changes.


'92 Barth Breakaway - 30'
5.9 Cummins (6B) 300+ HP
2000 Allison
Front entrance
12-14-2017, 02:24 PM
Duane88
Although the electric heating elements are surrounded by a metal tube and insulated, the flame is a more concentrated source of heat and can under a certain set of circumstances more readily corrode the boiler area.

Both Norcold and Dometic sell a replacement cooling unit. There was a place in South Elkhart that actually rebuilt the cooing units, but the EPA shut him down. I do not think anyone rebuilds units anymore, because of the hazard of materials used as refrigerant. Even the corrosion preventive was/is a hazard.

I am not sure what anyone could do to improve the system, except try to increase the heat transfer to the heat exchanger inside the cooling compartment and freezer.

I did some heat transfer testing in the 90's and units only generated about 90 BTU, hence the reason for super thick insulation in the walls and specially the freezer compartment.


1971 24 ft Barth Continental
P30 chassis
350 engine