Replacing Fridge with AC version running off inverter/solar

[jasonv31]

I have read of others doing this in other campers... I really like the pros (cheaper fridge, running on solar and batteries for boondocking etc). I really don't see a lot of negatives. I am new to all of this though, but a capable mechanic and do most things myself. Let me know what yall think and is there anyone else out there that has done this in a trailmanor ? Thanks in advance !

EDIT- I mean an A/C only fridge NOT a AC/DC fridge. One that would fit, I have seen several models in the 4.3 cu and lower range.

EDIT#2 - I found this excellent blog on this very subject, gives ALOT of pros and cons to this modification that I will be doing.
http://www.livesmallridefree.com/blo...oondocking-rvs

[rickst29]

After you've got the running amps for the Fridge (off the label), you should almost certainly apply a factor of about 5x to properly size the inverter. For a few moments at the start of each running cycle, refrigerator and air conditioner Compressors need a lot more amps (and watts) to get started. After the motor has begun to move, it can be kept moving with much less power. The label shows the lower "continuous" amps, not the higher startup figure.

Your Inverter MUST have a maximum amperage value which can support this momentary load; without this extra power handling capability, both the inverter and the fridge compressor can be damaged. (Good Inverters will provide both figures, "continuous power" and "peak power").

A "small" compressor fridge (4 cubic feet or so) will use 70-110 watts while running continuously. ("AC" versus "DC" doesn't matter much. - Ambient versus internal temps matter a lot, and design pressures matter a lot.) So, the inverter for a cheap fridge of that rated "continuous power" input should probably be rated for a "peak power output" maximum of 600 Watts or better. (More "headroom" is better than less, of course.)
- - - - - -
You might also look at the venting requirement for the candidate refrigerators. The Dometic "Boat/RV" models which some of us use have fan-powered airflow over small coils, exiting almost exactly where TM placed the upper fridge vents. If your "home-style" fridge candidates blow hot air into the TM interior (from underneath the front), or require "installation spacing" on the top and sides with the hope of room airflow distributing the heat - they might not work as nicely.

[jasonv31]

Originally Posted by rickst29

After you've got the running amps for the Fridge (off the label), you should almost certainly apply a factor of about 5x to properly size the inverter. For a few moments at the start of each running cycle, refrigerator and air conditioner Compressors need a lot more amps (and watts) to get started. After the motor has begun to move, it can be kept moving with much less power. The label shows the lower "continuous" amps, not the higher startup figure.

Your Inverter MUST have a maximum amperage value which can support this momentary load; without this extra power handling capability, both the inverter and the fridge compressor can be damaged. (Good Inverters will provide both figures, "continuous power" and "peak power").

A "small" compressor fridge (4 cubic feet or so) will use 70-110 watts while running continuously. ("AC" versus "DC" doesn't matter much. - Ambient versus internal temps matter a lot, and design pressures matter a lot.) So, the inverter for a cheap fridge of that rated "continuous power" input should probably be rated for a "peak power output" maximum of 600 Watts or better. (More "headroom" is better than less, of course.)
- - - - - -
You might also look at the venting requirement for the candidate refrigerators. The Dometic "Boat/RV" models which some of us use have fan-powered airflow over small coils, exiting almost exactly where TM placed the upper fridge vents. If your "home-style" fridge candidates blow hot air into the TM interior (from underneath the front), or require "installation spacing" on the top and sides with the hope of room airflow distributing the heat - they might not work as nicely.

Thanks for tips... I've been looking at inverters in the 1000watt range. Mainly in case I want to run something else at the same time Going to probably start with 2-4 6v Trojan FLA battery's, 3 100watt panels renogy mono (or maybe HGST which is related to renogy and a bit cheaper) MTTP controller (30 or 40 amp). All of it appropriately wired to the correct gauge and fused. If i go with 2 Trojans (I need to see if that will be enough) I should be just around a grand for the whole setup. Not too bad considering...

P. S. I still need to research how this will integrate into the existing electrical system. I assume I will need an additional transfer switch as well... I've seen several that would work fine.

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[BrucePerens]

I'm very interested in hearing about the longevity of a dorm 'fridge in an RV, using an inverter. Obviously, you could afford to replace it every year if necessary. My DC 'fridge with the nice Danforth compressor is doing fine, and is maybe about 2X the efficiency (which matters when the sun isn't shining or if your panels are in shade) but it's pricey.

[jasonv31]

Originally Posted by BrucePerens

I'm very interested in hearing about the longevity of a dorm 'fridge in an RV, using an inverter. Obviously, you could afford to replace it every year if necessary. My DC 'fridge with the nice Danforth compressor is doing fine, and is maybe about 2X the efficiency (which matters when the sun isn't shining or if your panels are in shade) but it's pricey.

Yes thats one of my motivations (cost) ... I will document here my results. Since it looks like my AC is fine (I will probably replace it next season with a larger unit) I will invest in more battery. I've already gotten the old dometic pulled out. (anyone need one from 1996 ? hahaha but seriously if anyone needs it and is in the southeast tx area... let me know. Pics below)

As far as longevity of the mini fridge it should be just fine as long as you observe two things, good power (make sure its a decent "pure sine" inverter, just because your fridge runs fine on a cheaper non pure sine inverter, doesn't mean its not doing long term damage to it and 2) as mentioned by @rickst29 making sure its got enough cooling if that's needed for the model you get. (these two things are confirmed by my reading many others on the internet running home fridges on inverters)