24V DC RV Air Conditioners With Solar Boondocking Performance

[Primerump]

I don't normally post customers work on here, but I thought this might be of interest for anyone contemplating a move to DC
a/c units. these here are fitted to an outdoors rv 22fqs. the rear unit replaced a 13500 dometic ducted unit. the front replaced a max-air fan. both units are part of a conversion to 24V dc aircon and also 1400 Watts of solar on the roof. additionally, the battery capacity has been upgraded to 19,200 w/hrs the 12V battery on the tongue is now a self heated 100a/h lithium.

the ducted units ducts have been sealed to prevent air return on the new unit.

these pictures were taken a few days ago with ambient temps at 100 degrees. in the window of the front picture one can see another rv, this is a customers KZ unit with a 13500 btu mach 3. for comparison, I ran both systems at 100%. after a few hours in the sun, the KZ settled at 85 degrees, the ac clearly struggling. The two DC units in the ORV throttled back and maintained a steady 74 degrees. power consumption for the KZ was 1300Watts and the total consumption of the DC units was measured at 1000 W

solar production at the time of measurement was just under 1200W. so this unit produces a surplus in the sun even when cooling.

forgot to mention, the system ( all victron ) has a 3000 W multiplus inverter/charger too..

 

[IBTripping]

Congratulations on the upgrade. I think the efficient DC air conditioners are a great innovation for RVs especially for owners who like to boondock.

 

[DonTom]

The DC Air Conditioners in EVs are MUCH better than any others I have seen for countless reasons, so should be the same for RVs . . . Except for one little fact. EV A/Cs runs from the HV battery, usually around 400 VDC.

Not many RVs have 400 VDC available.

-Don- Big Creek Camp, NV

 

[Primerump]

The DC Air Conditioners in EVs are MUCH better than any others I have seen for countless reasons, so should be the same for RVs . . . Except for one little fact. EV A/Cs runs from the HV battery, usually around 400 VDC.

Not many RVs have 400 VDC available.

-Don- Big Creek Camp, NV

higher voltage usually results in better efficiency, it would be foolish of EV manufacturers to have used 12V for the A/C.. LOL

for the orv rig, the client initially suggested 12V, but after explaining high currents and heavy cabling issues, they agreed and i designed the system for 24V. the client is very happy with the result and should enjoy many years of boon docking.

also, after looking over the ORV, i'm tempted to seek one out for myself. my wife and I would like to go a bit smaller than our AF 25R. my only consideration, as was the clients, is the rather poor choice of schwintek slideout controls. I did suggest the VRoom replacement. I contacted vroom and for this rig they quoted $4000 for the upgrade.

 

[DonTom]

higher voltage usually results in better efficiency,

I would say "always" instead of "usually". Less current draw at higher voltages for the same wattage, less heat on the wires, etc.

If there are any disadvantages of using a higher voltage, other than possible safety concerns, I would like to know what they are.

-Don- Big Creek Camp, NV