mdshaw
mdshaw Reader
9/13/21 4:45 p.m.

It's never worked that great-the Norcold 1200 in the slide out. Have done all the tricks, narrowing the top vent to concentrate the vent air, added fans. Then it almost caught on fire & fortunately tripped the over temp sensor. 
Replacing it with a 12v hvac compressor. Getting rid of the 120vac/propane cooling unit. Being 20 years old, it has far outlived it's life expectancy anyway. 
The old cooling unit was very rusty & looking close to rusting through. 


 

Toyman01 + Sized and
Toyman01 + Sized and MegaDork
9/13/21 5:06 p.m.

Following this one. Are you replacing the entire unit or just installing a 12v compressor in the existing case? 

alfadriver
alfadriver MegaDork
9/13/21 5:27 p.m.
Toyman01 + Sized and said:

Following this one. Are you replacing the entire unit or just installing a 12v compressor in the existing case? 

Me, too, same question.

We chose a new unit that looked like a normal fridge, but there are a lot of cooler style fridges that are quite a bit cheaper.

Toyman01 + Sized and
Toyman01 + Sized and MegaDork
9/13/21 5:39 p.m.

In reply to alfadriver :

I have one of the cooler style refrigerators and it works very well.

The refrigerator in my RV matches the cabinets I'd love to have modern guts installed in it. It looks like someone does make a conversion. Hopefully, that's what is happening here. 

alfadriver
alfadriver MegaDork
9/13/21 6:08 p.m.

In reply to Toyman01 + Sized and :

I kind of looked into those, and the price for the kit was the same as the price for a brand new fridge.  And a new compressor fridge has more space inside for the equal outside dimensions.

mdshaw
mdshaw Reader
9/13/21 6:39 p.m.

There was no way to get the fridge out of the rv without removing a windshield. The fridge door seals & electronics work well so a new cooling unit made sense. 
The dc cooling unit was $1095 + $250 shipping.  
The cabinet insulation was really dirty also.  Looks moldy but was just dirty. 

mdshaw
mdshaw Reader
9/13/21 6:56 p.m.

Removed all the old insulation & that rear vent deflector. Then found the base was collapsed. Removed the base 1/4" plywood & found the supports were only attached with big staples. Under the support ribs it measured exactly 1 1/2" so ripped up a 2x4 & placed them under the ribs to actually give it some support. 

mdshaw
mdshaw Reader
9/13/21 7:37 p.m.

Glued in some 1" foam insulation  & put the plywood floor back in. Sprayed it starting in the back with a leftover can of white spray paint. Rain never seemed to get in there but just in case.  Sealed up the joints.

Layed the fridge face down then removed the old cooling unit. There was only 4 sheet metal screws & lots of duct & foil tape holding the cooling unit on the back & 15 screws inside.



Then lots of thermal sealant to scrape off.

The control board had to be moved over 3" to clear the new cooling unit.

 

mdshaw
mdshaw Reader
9/13/21 7:40 p.m.

Here's the old nasty cooling unit removed.

mdshaw
mdshaw Reader
9/13/21 7:56 p.m.

Before placing the new cooling unit, the plates get good beads of heat sink sealant- which is supplied. Then the cooling unit is placed on the fridge & 15 new self tapping screws - also supplied. Then spray foam the edges around the plates & foil tape over the foam. Spray foam & foil tape was also supplied.

Pete Gossett (Forum Supporter)
Pete Gossett (Forum Supporter) MegaDork
9/13/21 7:59 p.m.

In reply to Toyman01 + Sized and :

We just got this $400 fridge for the RV. It did have a few bumps & dings, but fortunately none were on the front so they're not visible mounted in the RV. 

I did look into a 12v conversion kit for our Dometic, but it was around $850-shipped & there wasn't any advantage to us for keeping it. 

I did have to take a sawzall to the Dometic to get it out the side door though. 

mdshaw
mdshaw Reader
9/13/21 8:12 p.m.

Wrestled the unit back into place, put the 8 mounting screws back in & finished the wiring per the instructions. 
To isolate the air to the rear, stuffed oversized backer rod up each side in the back & rolled the old insulation tight & stuffed it across the top. Also removed the ice maker which we never used & removed the propane flex line back the the black pipe & capped it.

The unit now runs on 12v dc only.
On the control panel inside you set it to run on LP.  Since it uses a compressor, the level is not so critical now. 
It will require more battery capacity when dry camping so ordered a 200ah LFP battery from Aliexpress.  For now the agm's will provide the 12v but while on shore power  the inverter/charger provides the 12v & while driving, the Cummins alternator provides the 12v. Driving was the biggest issue before, the fridge used propane & it has never worked very well while moving. If using the roof a/c we would have the generator running & the fridge on AC but it still didn't cool that well & things in the freezer would not be frozen after driving for several hours. The airflow required for an absorption unit in a slide out is really tough.

Turned it on & it started getting cold fast. There is an included fin fan to keep the fridge section from icing up. So far so good.

Professor_Brap (Forum Supporter)
Professor_Brap (Forum Supporter) UltraDork
9/13/21 8:21 p.m.

It's small scale system of what I work with daily. 

mdshaw
mdshaw Reader
9/13/21 9:22 p.m.

This was big enough for me.

03Panther
03Panther UltraDork
9/14/21 3:41 a.m.
Professor_Brap (Forum Supporter) said:

It's small scale system of what I work with daily. 

Do you mean 12V DC compressors, specificity? Or commercial refrigeration? I've worked on refrigerant compressors from 110VAC up to three phase units, but had not seen the new 12VDC stuff. Way cool!

Professor_Brap (Forum Supporter)
Professor_Brap (Forum Supporter) UltraDork
9/14/21 4:43 a.m.
03Panther said:
Professor_Brap (Forum Supporter) said:

It's small scale system of what I work with daily. 

Do you mean 12V DC compressors, specificity? Or commercial refrigeration? I've worked on refrigerant compressors from 110VAC up to three phase units, but had not seen the new 12VDC stuff. Way cool!

Do a little 12v dc stuff, but mostly large 3 phase units. The new 12vdc stuff has so many safetys built it they are always shutting down. 

 

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