Propane refridge

[lederhos]

I’ll second Waverly’s comment. Got my dorm fridge on sale for $100 shipped free from Walmart. Doubled my refrigeration space (had to removed radio I never used), but I have a large lithium battery, a LOT of solar and a very efficient inverter

[barnyard]

Wavery -I like your idea about 110volt refridge. Is 1000 watt inverter suffficient? pure sine wave?

[Wavery]

Originally Posted by barnyard

Wavery -I like your idea about 110volt refridge. Is 1000 watt inverter suffficient? pure sine wave?

A 1000W inverter would work just fine. Just don't plan on running much of anything else that's 110V. If you are going to all the trouble of installing an inverter, I'd recommend a 2,000W so that you can run a coffee pot or microwave. If you don't use those, you're golden.

Just be sure to use the proper sized pure copper wire (depending on the distance) from the batteries to the inverter and a 100A Mega Fuse in the line.

What batteries are you using and do you have solar?

[barnyard]

kinda entry level and large learning curve. Just bought 07 2720 w/ trashed refridge. just purchased 4.4 cu, ft. unit 110volt Have 100watt panel and ep ever controller,2 6v golf cart batteries from years ago. Question: better to have inverter close to batteries w/ long110v cord or inverter close to refridge and long 12v wires? Thanks for input

[Wavery]

Originally Posted by barnyard

kinda entry level and large learning curve. Just bought 07 2720 w/ trashed refridge. just purchased 4.4 cu, ft. unit 110volt Have 100watt panel and ep ever controller,2 6v golf cart batteries from years ago. Question: better to have inverter close to batteries w/ long110v cord or inverter close to refridge and long 12v wires? Thanks for input

Put the inverter as close to the batteries as possible. DO NOT use the battery cables that came with the inverter. 90% chance that they are copper coated aluminum (CCA) and that's not good. You want to have pure copper battery cables and they should be the proper size, depending on the size of the PURE SINE WAVE inverter (Don't buy a modified sine wave inverter) and length of the cable. You can run a long wire to your fridge or just wire the positive wire from the inverter into the fridge circuit breaker and the negative wire into the ground busbar in your power center. If you do that, you can just use the 110V outlet that is already inside your fridge cabinet, behind the fridge.

If your batteries are over 3-years-old, don't plan on them performing very well. If over 5-years-old, you may want to replace them with a 100AH lithium battery (or 2).

[barnyard]

with the 110 volt refridge is it necessary to keep the cooling fan behind unit?

[Bill]

Originally Posted by barnyard

with the 110 volt refridge is it necessary to keep the cooling fan behind unit?

The short answer is that it may not be strictly necessary, but it is probably a good idea to keep it.

Why? All refrigerators create some heat as they cool the food area, and the refrigerator MUST get rid of that heat in order to function. Compressor refrigerators create much less heat than absorption (3-way) refrigerators, but the heat still should not be trapped and allowed to build up.

So in regard to your question, some compressor refrigerators have an array of vertical cooling tubes (usually colored black) on the back. They remove the heat by letting air circulate from the floor, up the back of the unit and over the tubes, over the top, and out into the room. Others have an array of horizontal cooling tubes at the bottom, just above the floor. They have a small fan to blow air from the back near the floor, across the coils, and out into the room.

Either way - but especially with the vertical tube arrangement - if venting is not good, the heated air will tend to collect in the area behind the refrig. I would consider it a good idea, though perhaps not strictly necessary for a small refrig, to exhaust this air outside.

Bill

[Bill]

A couple small points to consider.

1. In the summer, you may not want the refrigerator's waste heat to be exhausted into the room, so blowing it outside with the exhaust fan might be welcome. But in a colder season, you might welcome it inside. Then you turn off the exhaust fan, and keep that warm air inside.

2. As noted above, a refrigerator MUST get rid of the heat that it generates. That is part of the physics of refrigeration. If the heat is allowed to build up, then the refrigeration mechanism must work harder (longer) to overcome it. This means that the refrig uses more electric power. If you are boondocking, using the small amount of power to run the fan may be worth it.

Bill

[Wavery]

Originally Posted by barnyard

with the 110 volt refridge is it necessary to keep the cooling fan behind unit?

The short answer is "No" you do not need to keep the cooling fan if you install a compressor fridge.

The long answer is:
I think that you might be asking this question because the old exhaust outlet may be prevention you from pushing the new fridge all the way back into the cabinet.

I was faced with that and my wife was happy with having the fridge stick out the 1.5 inches from the cabinet. If she wanted the fridge totally flush, I would have removed that vent hose flange and rearranged it to be out of the way.

In reality, that exhaust vent was really made for the heat that was developed for the old fridge to operate. With the old ammonia fridge, the burner (either propane or electric) had to get quite hot to boil the ammonia to make the fridge work. There is no "Heating" element in the compressor fridge and the amount of heat that needs to be exhausted (if any) is minimal and occurs naturally through the vented panels behind the fridge.

Think about the fridge in your home. There is no vent for that fridge. Back in the 1940s and into the 50s a lot of homes had propane/ammonia fridges in them (if they could afford it). Those fridges had to have exhaust vents through the roof, just like a gas water heater.

[rickst29]

Originally Posted by kjfatl

I picked a compressor frig that runs at 110V or 12V. It uses 110V if available and falls back to 12V when necessary. I was concerned that a continual load on the 12V inverter would reduce the life of the inverter unnecessarily. In the long-term I will probably get a larger solar panel for the top of the camper that can keep the frig going when AC power is disconnected for an extended period of time.

Your fridge, like mine probably RUNS on "12v". These convertible types contain contains a small power converter, from 120-VAC to 12 Volts DC, with a sensor which switches to use the "converted AC power" whenever AC is present.

Much smaller than the main RV converter, this converter only needs to supply about 70-90 watts.