Cooling residential refrigerator overnight

[Chance]

Originally Posted by TurnerFam

call me crazy, but I don't know of any reason an inverter would be supplied, along with an AGS automatic generator start, if there were no Charger included - how else would the batteries be charged?

Many units appear to come with a separate stand-alone converter for battery charging, and then add an inverter to power fridge, etc.

I personally think the better way to simplify the installation is to use an inverter/charger, but that's not always done. In this case I'm not sure what is supplied on that model.

[Chance]

P.S. -- Specs (2017) indicate larger models come with battery tray capable of holding 4 batteries. If that applies here, it may be a nice future upgrade to keep fridge running longer without having to use generator as often. Just a thought.

[TurnerFam]

Originally Posted by Chance

Many units appear to come with a separate stand-alone converter for battery charging, and then add an inverter to power fridge, etc.

I personally think the better way to simplify the installation is to use an inverter/charger, but that's not always done. In this case I'm not sure what is supplied on that model.

right, agreed, I'm sure that each different model has different requirements and setup to determine whether it's a combo inverter/charger, or separate. It may also be due to size of the Magnum combo unit, where the smaller RVs don't have the place for it.

[Logalinipoo]

I know this thread is a little old, but just a thought. Is your inverter in the basement? Mine is. You might just unplug from it and plug in your extension cord to the house.

That is if the inverter is not hardwired on the outlet side.

[Bigfoot]

Slightly old thread bump.

I was at a dealer yesterday and asked them about what power sources the residential fridges worked from.

He said "oh both propane and 110!"



(rule #1 don't listen to the salespeople)

So the OP shouldn't be too hard on himself.

I got the model number of the fridge and confirmed it was 110v only (this is in a Miramar).

But the issues I can see with a residential fridge are:
1) you have to run the inverter whenever you want the fridge on
2) that is maybe less efficient than a fridge that will run off 12v and/or propane

They apparently get cool quicker and stay cool easier.

[Chance]

Agree sales people are often not well informed on technical issues. And it's understandable because RVs have become so much more complicated, although in the case of residential refrigerators it would seem straight forward.

Originally Posted by Bigfoot

....cut.....

But the issues I can see with a residential fridge are:
1) you have to run the inverter whenever you want the fridge on
2) that is maybe less efficient than a fridge that will run off 12v and/or propane

They apparently get cool quicker and stay cool easier.

If the inverter or inverter/charger has a transfer switch, whether built-in or standalone, the residential fridge will run directly off the grid or off the generator without needing the inverter to be operational.

Regarding efficiency, the "normal" RV fridge uses an absorption cycle that runs off heat. When on propane a flame provides the heat. When on 12 Volts it uses the batteries to provide heat (versus running a compressor). As I recall efficiency is not great, although I'd have to look it up to compare accurately.

There are some newer RV refrigerators that run on 12-Volts but by powering a 12-Volt compressor. As such it eliminates the need to use an inverter -- battery power goes directly to compressor. Specifications show these are efficient, but we need to keep in mind that inverters can be efficient too, so we'd have to compare a 12-Volt DC compressor versus a 115-Volt AC residential compressor to see which is more efficient, and then adjust for 80 to 90 % inverter efficiency. I would guess the difference between these two options isn't great.

Some smaller fridges used on all-electric Class Bs run on 12-Volt using a high-efficiency compressor. They seem pretty efficient. In time I expect/hope RVs will convert to 48-Volt DC systems and that should make them even more efficient.

[Bigfoot]

Originally Posted by Chance

If the inverter or inverter/charger has a transfer switch, whether built-in or standalone, the residential fridge will run directly off the grid or off the generator without needing the inverter to be operational.

Right, I meant to say "off the hook", on the hook is pretty straightforward.

Some smaller fridges used on all-electric Class Bs run on 12-Volt using a high-efficiency compressor. They seem pretty efficient.

Right, I have one of these in my Class B. With 2 x 130W solar panels and the house batteries I never need to plug in, to keep the fridge running. But it is only 4 cuft.

Maybe the biggest issue depending on the model of RV/inverter is remembering that the inverter needs to be switched on for the fridge to work off the hook.

For a fridge that is 110v only and where you are keeping a bunch of food in it, some kind of alarm for loss of 110v power to the fridge might be an idea in case a breaker pops, someone switches the inverter off or whatever.

I know a lot of the newer Class A's have automatic generators and transfer switches etc, but somewhere, sometime, something will switch itself off.

[RobbieH]

I have a residential fridge in mine. I just keep my RV plugged in at all times. No reason not to. It costs very little to keep it plugged in just to run the fridge. I even use mine for overflow from the house fridge when I need extra storage. 110v will do just fine as long as you are not trying to run your AC units, water heater, and fridge all at the same time.