Chest freezer fridge mod...

Wow, as my first post let me just say the wealth of information (much of which is conflicting) out there is beyond overwhelming. Thankfully I just have the mindset of "let me get started making my mistakes and go from there".

I have been crunching number on my new solar setup and part of being off grid or extended dry campings means major lifestyle changes. Clearly I need to address keeping food cold/frozen and here's what I came up with from least to most efficient:

Stock Norcold fridge/freezer: 6.7kwh per day

Large home side by side: 3kwh per day

5 cubic foot GE chest freezer: 0.5kwh per day (set to #2 which keeps it at 0 degrees)

I can't say I'm totally shocked by this after giving it some thought but it wasn't what I'd expected.

Clearly a chest freeze is the way to go when trying to stay off grid and they make some even more (15%) efficient (based on their number) that fit directly into the stock Norcold hole.

The issue being now you don't have a fridge.

So here's my solution and I would like to know your thoughts.

1) Rivit 3/4 aluminum angle stock all the way around the inside about 18" from the top (looks like this won't interfere with anything).

2) Make a selve out of 1"-2" foam insulation (the type with a backing).

3) Stock the top portion with items you want to keep warmer.

Obviously if you left it like this for a week everything would end up frozen but the idea is to find a balance of use/insulation thickness that the bottom portion stays isolated from being opened and the top portion doesn't freeze (as quickly) due to being opened and isolated from the main cooling area.

This may also allow you to use the stock temp controller.

Any thoughts, input, ideas?

I'm sure you will see a lot of ideas like this posted by me as I get ready to do a couple month off grid adventure with my kiddo. I'm getting my 5th wheel ready now so the ideas are flowing.

As a side note, the price I get for the used Norcold should pay for this entire "upgrade".

BobandShaz
Explorer
Apr 29, 2014
FMCA magazine has a list of freezers for Rvs. Can u post some pics.
Roadpilot
Explorer
Apr 29, 2014
We have an LG fridge that uses a similar concept. It's shown here:

LG

You can open the right hand top door two ways. The first gives you access to the stuff you use a lot. Milk, butter, etc. The other way gives you access to the inner compartment you access less frequently.

Between these two compartments is clear plexiglass with a small cutout. The cutout allows cool air to get to the front compartment but isn't big enough to allow a lot of air to escape from the rear when the front is opened.

I don't think you'll need the insulation, just an air barrier between to the top and bottom. The top will be opened a relatively short time so the conduction losses will be small from bottom to top versus convection losses. Just stop the convection loss.
westend
Explorer
Apr 29, 2014
I'd bet a pack of popsicles that anything put in the freezer will freeze unless you can adjust the temp control for refrigerator temps.
popeyemth
Explorer
Apr 29, 2014
Why not use the freezer to freeze, and freeze ice and use a cooler?
MrWizard
Moderator
Apr 29, 2014
Don't run the Norcold on electric
USE PROPANE

If you want Electric fridge, then replace Norcold with residential compressor fridge and install large battery bank plus solar plus generator
RRBob
Explorer
Apr 29, 2014
Here you go................
Gdetrailer
Explorer III
Apr 29, 2014
popeyemth wrote:
Why not use the freezer to freeze, and freeze ice and use a cooler?

Chest freezers tend to have much more insulation which when converted to a fridge will result in an extremely energy efficient fridge..

Take a look at a good write up on such a conversion which the author managed to get his down to .1KWh usage per day

HERE

A beer fridge T stat can be used instead of the freezer T stat..
rkentzel
Explorer
Apr 29, 2014
Better by two or three of them that way when you get into the copper tubing and puncture a hole and let all the cold out by the fourth one you may know where all the gas lines are.
TucsonAZ
Explorer
Apr 30, 2014
Provided we're adhering to the laws of the universe this is a solid plan in terms of energy and how it will behave. Provided the freezer manufacture hasn't deviated from nor altered their schematics as part of some nefarious plot to thwart my attempts to conserve energy it's also solid.

The variable here would be achieving a balance of using the "fridge" portion enough (opening the top) and adjusting the "freezer" portion to keep the top area from freezing. I'm guessing say 30 degrees down below may allow for this. I guess time will tell but somebody has to do the experimenting.

I can say that the bottom of my chest freezer is 0 degrees, the top of the lid (inside) is 12 and the top of the lid on the outside is 75 so it's behaving as I would expect for this plan to be functional.

The only caveat is that I'm kind of out there so you may all know better than me and as rkentzel mentions I may drill into a coolant line and end up dead over this but my family case sue GE (this is America after all) for not having their cooling lines where their diagrams depicted them. If you don't hear back from me assume the worst /:
rkentzel
Explorer
Apr 30, 2014
I would not totally go on the diagram these lines are foamed in place and can move a bit.