AC vs DC air conditioner on shore power?

[mega5]

Looking for some input on this.

I will have a 10KW 24v bank so obviously the natural choice would be to use a 24vdc A/C. I'm just a bit confused on what will happen on shore power and make sure I'm not missing anything here.

-On shore power with DC air conditioner, I assume the multiplus will basically be acting as a huge voltage converter and charging the batteries plus providing enough amps to run the DC air conditioner. I believe this is all happening on the same circuit, so the current going into the batteries may be a little bouncy during this as when the Air conditioner is going between duty cycles. Just checking this isn't super bad or anything, I know the current into batteries is supposed to be steady if possible. I'm guessing this also will generate a bit of heat from the charger, so the fan might spin up or whatnot.

-On shore power with the AC air conditioner, I assume this would put the inverter in some kind of "pass thru" mode 120VAC while also charging the batteries on the dc circuit. Is the inverter on, but in "standby" during this? Any guess if the multiplus would be less/more noisy than the above scenario?

-Off grid: This one is easy, obviously DC is superior as the multiplus doesn't have to do anything and can actually be turned off.

 

[JRH]

Looking for some input on this.

I will have a 10KW 24v bank so obviously the natural choice would be to use a 24vdc A/C. I'm just a bit confused on what will happen on shore power and make sure I'm not missing anything here.

-On shore power with DC air conditioner, I assume the multiplus will basically be acting as a huge voltage converter and charging the batteries plus providing enough amps to run the DC air conditioner. I believe this is all happening on the same circuit, so the current going into the batteries may be a little bouncy during this as when the Air conditioner is going between duty cycles. Just checking this isn't super bad or anything, I know the current into batteries is supposed to be steady if possible. I'm guessing this also will generate a bit of heat from the charger, so the fan might spin up or whatnot.

-On shore power with the AC air conditioner, I assume this would put the inverter in some kind of "pass thru" mode 120VAC while also charging the batteries on the dc circuit. Is the inverter on, but in "standby" during this? Any guess if the multiplus would be less/more noisy than the above scenario?

-Off grid: This one is easy, obviously DC is superior as the multiplus doesn't have to do anything and can actually be turned off.

That is a great point … I didn’t know till last week they even made DC a/c units …13.5 A/C is getting old now and will need replacing soon… I need to find out more… this may make a lot of sence for many people in the future…but I don’t know enough yet ,to know.
everytime I think I’m all set, somthing new comes out….then I think I need it…!!

 

[justinm001]

Yes you're right. On shore the inverter will passthru the power to the rest while charging the batteries. It'll also let you limit AC shore input so you can use 15amps only. And will assist so if you're running on 15amp cord you can actually use the 15amps plus your inverter then it'll go back to charging the battery when done. Perfect for using microwave while AC is on.

If the inverter isn't inverting or charging when on shore it should be silent or almost silent. Itll just float and keep the batteries topped off while you can continue to use it.

I have the bigger Quattro and it's basically silent unless inverting or charging large loads, the fan spins up more/less depending on temps so sometimes it'll be quiet and other times you can hear it. It's not loud though. Quiet enough we actually put it next to my bed on my old coach. Ripped out the bedside table and put the rack batteries then inverter on top, Planned on framing around it but ended up just buying a new coach. It was loud for a couple hours when we pulled up to a CG then silent so as long as we didn't pull up to a CG and go right to bed it wasn't noticeable.

I don't think there's any major issue with large loads on the battery, it's pretty normal. You might have to adjust your alert settings so you don't get errors for DC ripple or high/low depending on how hard it affects it.

Not sure the DC amp draw of your AC unit and the DC charging amperage of the inverter but you should make sure it's more than the AC unit.

The question I always wonder is how much more efficient is DC ac units over AC? It seems they use a lot less power but typically they're smaller and more efficient units.

 

[mega5]

If the inverter isn't inverting or charging when on shore it should be silent or almost silent. Itll just float and keep the batteries topped off while you can continue to use it.

Ok thats good to know

The Victron 24/3000 charger output is 70 Amps @ 24v = a whopping 1,680w (not even counting solar input), so with a 24vdc a/c like the Velit which is 33a @24v maximum, the Victron would still have 37 amps in reserve for charging the batteries. So really could do the AC or DC air conditioner just depends what is going to make more sense.. could also just stick with the good old "air tunnel" and wait for prices to come down a bit more and get a portable AC unit in the meantime. There seems to be new DC units coming out all the time now and the Chinese ones are starting to look half decent, especially the mini split one which mounts on a rear cargo door.