I need help deciding on a rooftop AC unit

E350

Well-known member
The Dometic rooftop AC in the Sprinter was tripping our garage's 120VAC 20 Amp breaker with a 12AWG 100' cord.

Upgrading to this 10AWG 100' cord stopped it from tripping the circuit breaker:

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Fits well in this:
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I will use our existing Dometic rooftop AC for now and see how it goes. I have to remove the interior piece to even view the label to know what model it is, but I know it is not 12VDC.

I wonder if two of the Dometic RTX2000 12VDC units would be an efficient design. Use one unit over the drapery enclosed sleeping area at night and, during the day, use an additional unit over the area behind the cab as needed.

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@Built.Vans How does your customer like his single Dometic RTX2000 12VDC unit? What do you think of the dual installation design postulated above?
 
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akadaedalus

Well-known member
I have the Mabru. Install documented here, and Styrofoam/XPS insert re-do documented here.

Like some disorganized idiot I didn't do the initial power on test until November. Surprisingly it blew cold air immediately... because it was already cold in Utah.

We haven't done a practical test in full summer heat but so far it's promising and barely sips from my 800 Ah Lithium bank. No need for the engine to start it.

Any suggestions on how to test it? I could turn it on tomorrow and take some recordings through Victron VRM... Supposed to hit 80 degrees.
 

akadaedalus

Well-known member
On impulse I bought a Ruuvi tag to run experiments.

It's overcast today so probably not a great day to test but:
  • Outdoor temperature is 74 degrees-ish.
  • Van interior temperature started at around 88 degrees-ish. I put the Ruuvi on a canvas camping chair to hopefully cut down on measuring the heat on interior surfaces. It is a little bit close to the A/C unit but I tried to set it away from the A/C blast.
  • I set the A/C to max cool at 60 degrees.
  • My neighbor looked at my van wondering why it was running. It is noisy but not as bad as, say, the engine running or the Espar heating.
  • In about an hour of running it dropped about 11.5 degrees (76 F).
  • In that same hour it consumed energy at a rate of about 35-45A. Solar has been offsetting the energy loss but not a huge amount since, again, it's overcast. I'm not sure exactly what I'm seeing in the graphs and may need to tweak my Victron/VRM configuration.
I called the experiment off after two hours when it was a frosty 69 degrees. It's not Vegas or Texas heat, or even normal Utah heat, but it's promising.

Ruuvi vs approximate ambient temperature. Little uptick in the end when I opened the van to turn off the A/C:

temps1.jpg

VRM graph is a little confusing. I think the numbers are for 15-minute chunks. Peak consumption was something like 0.16 kWh and dropped to 0.10 kWh near the end.

temps2.jpg

If conditions are similar tomorrow (van temp 10 degrees above ambient temp) I might see what happens if I just open the windows and turn on the Maxxair fan.
 

Rocksnsalt

There Can Be Only ONE
What’s a ruuvi tag.

Edit
 

hotdogwater

Member
REAL WORLD EXPERIENCE HERE....
I have the Dometic RTX 1000 on my 144 and just spent a week in Texas during a heat spell that was way hotter than we expected. I have a shore power unit that converts from 110v to 12v and plugged it in when we arrived. The AC and the shore power ran for 3 days straight without an issue! At the hottest part of the day, the van was about 83* inside (outside temps were 104* with feels like around 113* and 70% humidity). At night, the van was more than cool and had to turn it way down at night to not "freeze" inside. The van is fully insulated with thinsulate only.

Another note: (saw some misleading comments on consumption) I have a single 100ah LIFEPO4 battery and it was able to run the AC for about 6hours in eco mode. The AC pulls less than 400 watts when running the compressor and fan on high. I have not experience with the other 12v AC units coming out but the claimed BTUs seem a little high to me. The RTX 1000 is under 4000BTU so where they are getting the 13000 BTU from these other 12v AC units seems off. I get that standard window AC units/110v RV units are 13000+ BTU but maybe the 12v units are measured differently?

Sometimes I wish I got the RTX2000 but with my limited battery supply I am glad I got the RTX1000 and having just tested it in the TX heat for a week I think it can handle most anything we will be camping in.
 

Rocksnsalt

There Can Be Only ONE
REAL WORLD EXPERIENCE HERE....
I have the Dometic RTX 1000 on my 144 and just spent a week in Texas during a heat spell that was way hotter than we expected. I have a shore power unit that converts from 110v to 12v and plugged it in when we arrived. The AC and the shore power ran for 3 days straight without an issue! At the hottest part of the day, the van was about 83* inside (outside temps were 104* with feels like around 113* and 70% humidity). At night, the van was more than cool and had to turn it way down at night to not "freeze" inside. The van is fully insulated with thinsulate only.

Another note: (saw some misleading comments on consumption) I have a single 100ah LIFEPO4 battery and it was able to run the AC for about 6hours in eco mode. The AC pulls less than 400 watts when running the compressor and fan on high. I have not experience with the other 12v AC units coming out but the claimed BTUs seem a little high to me. The RTX 1000 is under 4000BTU so where they are getting the 13000 BTU from these other 12v AC units seems off. I get that standard window AC units/110v RV units are 13000+ BTU but maybe the 12v units are measured differently?

Sometimes I wish I got the RTX2000 but with my limited battery supply I am glad I got the RTX1000 and having just tested it in the TX heat for a week I think it can handle most anything we will be camping in.

RTX 1000 is 4094btu
(RTX 2000 is 6824btu)
That’s quite interesting. 🤔
Is your van white?
Any solar contribution?
Were you in shade the whole time?

Hard to understand how 4094btus is doing the job in that Texas heat I’m seeing on the news, but hell ya
100% Glad it’s working well for you!

 
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Spare_Mag_Mike

Wondering why WE THE PEOPLE let it get this bad.
I still think a recpro 9.5k with 2 fans is the way to go for me down here in TX... I'm waiting on my kitchen to be finished then I'll start my van build. Ill start with fans, AC, floor and insulation on everything. Then go from there! Shore power, inverter generator and a GZ3000x will be my power sources.
 

Rocksnsalt

There Can Be Only ONE
I still think a recpro 9.5k with 2 fans is the way to go for me down here in TX... I'm waiting on my kitchen to be finished then I'll start my van build. Ill start with fans, AC, floor and insulation on everything. Then go from there! Shore power, inverter generator and a GZ3000x will be my power sources.

Good plan.
So AC and fan(s).
How about Fridge? Cooktop? Coffee maker? Charging electronics?
You may find you need more power than the GZ3000X can provide.
I know it was a while back, but thought you were looking at the 5kwh ecoflow power kit?
 

rafski

Well-known member
What’s a ruuvi tag.

Edit
Ruuvi tags are the only bluetooth sensors (that I know as of 2023) that work with the Victron system. I have one in my van room and fridge. Also have alarms setup that work with the Victron app and will send me a notification to my phone if the fridge broke or the room is getting too hot while parked.
Works fine, even with my Raspberry Pi Victron hack.
1688055731299.png
I've been waiting for a hot day to do a similar battery load and AC test with my cheap hardware-store portable AC unit.
 

Spare_Mag_Mike

Wondering why WE THE PEOPLE let it get this bad.
Good plan.
So AC and fan(s).
How about Fridge? Cooktop? Coffee maker? Charging electronics?
You may find you need more power than the GZ3000X can provide.
I know it was a while back, but thought you were looking at the 5kwh ecoflow power kit?

Isotherm cruise 65 for fridge, drawer gun safe lock on 9v battery, espar heater, lighting interior and camp lights. Im a gas kinda chef so ill prolly do a camp chef propane 2 burner.

Still debating water system dont know if I wanna go wheel well tank and 12v pump or go with the more simple system of the 7 gallon under galley with a foot pump system.

Still debating house power system, might start with the GZ and upgrade to a full system when and if I need to. love the ecoflow power system but the price point hurts a bit for the 5kwh and the 2 just seems maybe underpowered for a baseline.

Mostly just 4 day trips out of the van during deer season and weekend trips in the off season all my electronics are charged from milwaukee m18 batteries with their inverter attachment (how ive been recharging my thermal drone for years) or are ran on single use 123a or AA batteries.

So main consumers are fridge, fans and heater( in winter) ... don't use lights much cause I take any excuse to put on my night vision helmet lol.

from back when I was hunting from a travel trailer camper I would turn on the dometic 13.5k on as soon as the sun broke the treeline and it would freeze me out of the 28' camper so im thinking with good insulation, proper shade parking (kinda hard to find an open area on my hunting grounds anyways), good ventilation while gone from the van with the fans, and a reliable power source from either gen or shore power the 9.5k by recpro will be plenty to get to comfortable sleeping temps... lol that is for when I wanna sleep and not chase the nocturnal critters.
 

hotdogwater

Member
RTX 100 is 4094btu
(RTX 200 is 6824btu)
That’s quite interesting. 🤔
Is your van white?
Any solar contribution?
Were you in shade the whole time?

Hard to understand how 4094btus is doing the job in that Texas heat I’m seeing on the news, but hell ya
100% Glad it’s working well for you!
Thought I saw the BTU for RTX 1000 was like 39xx. Either way, it was just about enough to keep the van tolerable in those conditions.

Yes my van is white, It has zero solar at the moment, trying to maximize coverage and stay within my roof rails so waiting on latest panels to get my 300+ watts. I did try to put a popup tent/shade over the front but it didn't work very well and removed it after a few hours on one day. I had a little shade from the house, but not very much (near zero) after noon. We didn't go in and out a bunch either and had my window shades up and a blanket up to block off cab area for much the day. I do have some reflectix on my roof above the thinsulate but only on the celling. One rear window on slider door with curtain.

This was worst case for us, so where we live (and camp mostly) in Colorado it's more than enough. We planned out our trip to get down to TX before the heat came and just got he beginning of this crazy heatwave while we were there last week so I was more than impressed with the AC. I plan on adding solar, and some more battery capacity as budget allows.
 

Rocksnsalt

There Can Be Only ONE
Isotherm cruise 65 for fridge, drawer gun safe lock on 9v battery, espar heater, lighting interior and camp lights. Im a gas kinda chef so ill prolly do a camp chef propane 2 burner.

Still debating water system dont know if I wanna go wheel well tank and 12v pump or go with the more simple system of the 7 gallon under galley with a foot pump system.

Still debating house power system, might start with the GZ and upgrade to a full system when and if I need to. love the ecoflow power system but the price point hurts a bit for the 5kwh and the 2 just seems maybe underpowered for a baseline.

Mostly just 4 day trips out of the van during deer season and weekend trips in the off season all my electronics are charged from milwaukee m18 batteries with their inverter attachment (how ive been recharging my thermal drone for years) or are ran on single use 123a or AA batteries.

So main consumers are fridge, fans and heater( in winter) ... don't use lights much cause I take any excuse to put on my night vision helmet lol.

from back when I was hunting from a travel trailer camper I would turn on the dometic 13.5k on as soon as the sun broke the treeline and it would freeze me out of the 28' camper so im thinking with good insulation, proper shade parking (kinda hard to find an open area on my hunting grounds anyways), good ventilation while gone from the van with the fans, and a reliable power source from either gen or shore power the 9.5k by recpro will be plenty to get to comfortable sleeping temps... lol that is for when I wanna sleep and not chase the nocturnal critters.
Yeah I forgot about you planning on a generator.

Lol re
any excuse to put on my night vision helmet lol.
 

E350

Well-known member
Very smart. We have a gasoline generator to power the well pump if grid power is lost for a significant amount of time.
 

Mein Sprinter

Known member
I still think a recpro 9.5k with 2 fans is the way to go for me down here in TX... I'm waiting on my kitchen to be finished then I'll start my van build. Ill start with fans, AC, floor and insulation on everything. Then go from there! Shore power, inverter generator and a GZ3000x will be my power sources.

Our 9.5 BTU serves us just well enough... remember its the humidity that's the killer... Been in 90-100F heat but very dry...inside it gets to 75-78F, very comfortable assuming the humidity remains low. If humidity increases... the interior climbs to about 80F with a 9.5 BTU Houghton, but still reasonably dry interior.
 

akadaedalus

Well-known member
Ruuvi tags are the only bluetooth sensors (that I know as of 2023) that work with the Victron system. I have one in my van room and fridge. Also have alarms setup that work with the Victron app and will send me a notification to my phone if the fridge broke or the room is getting too hot while parked.
Works fine, even with my Raspberry Pi Victron hack.

Sorry I wasn't clear on what a Ruuvi tag is and why I got it. I've been on a home automation kick lately and it's just one more sensor device to add to the fold. I got it exactly for the reason stated above -- it explicitly works with VenusOS (e.g. Cerbo GX or a Raspberry Pi like mine). What I also discovered is that it is a Bluetooth BLE beacon so it will work with multiple receivers, and thus I was also able to add it to a "Home Assistant" server I built, and that was how I compared the Ruuvi output to a weather service. I'll probably get more to monitor the fridge temperature and maybe the exterior temperature.

The reason I want to keep a remote eye on the temperature is because the A/C is more for my dogs than their humans. There may be times where we have to go inside for a few minutes without the dogs (groceries, restaurants), and having an off-grid A/C with battery and temperature monitors will give us peace of mind. I just need to design the Sprinternet....

Today was much sunnier so I decided to open my rear windows and run the Maxxair fan blowing out to draw cooler air through the windows. It wasn't that great at lowering the temperature but once I turned it off the temperature skyrocketed to 100+. The joys of a dark grey van...

temps3.jpg

On the battery side the fan was just sipping 4A at full throttle, and the solar panels were able to continue charging the battery.
 

Vangrant

Active member
Any Mabru owners out there with experience using the Mabru yet?
I figure with the horrible heat wave in Texas lately maybe someone has been able to put it to the test.
So I've had my Mabru 12k installed for a few months now, and as I'm sitting in my van at a KOA I figured I would give my honest opinions on it.

I installed my unit using a DIYvan adapter ring + their seal. Installation was very similar to the way I installed my MaxxAir. My AC is mounted in the forward position of my van. I have a full Adventure Wagon build out, and cut my own holes in the roof panels for the AC. I also cut the AC trim ring to accommodate my mule bag.

Initially, I used the cabling that came with the Mabru unit; however, I noticed that the wiring got warm when the AC was run in "max" mode. I ended up replacing most of the factory 6 Ga with 4 Ga using Anderson SB connector to adapt from the factory 6 Ga to 4 Ga. This not only reduced my amperage draw (no losses in the power cable) but also stopped the cables from getting hot.

I'm running the unit off of 2x Battleborn GC2 100 Ah batteries in parallel. I have a Progressive Dynamics 60 amp charge converter (PD9160ALV) that I use to charge my house batteries and run the Mabru off of shore power. This setup is killer and allows indefinite running of the AC off of 120 VAC shore power.

The reality is that if the van is in the sun, you won't be able to bring the temperature of the van down; however, standing under the AC is amazing for cooling down. Now, if you are in an area where the ambient temperature is high at night, that is where this AC is really killer. It's awesome for removing interior moisture and keeping the interior of the van cool as long as the sun is not beating down on the van. It is also very good at helping keep a pre-cooled van cool.

The AC throttles back periodically, I believe it's trying to conform to a duty cycle.

Overall, I'm happy with the purchase.
 

Rocksnsalt

There Can Be Only ONE
So I've had my Mabru 12k installed for a few months now, and as I'm sitting in my van at a KOA I figured I would give my honest opinions on it.

I installed my unit using a DIYvan adapter ring + their seal. Installation was very similar to the way I installed my MaxxAir. My AC is mounted in the forward position of my van. I have a full Adventure Wagon build out, and cut my own holes in the roof panels for the AC. I also cut the AC trim ring to accommodate my mule bag.

Initially, I used the cabling that came with the Mabru unit; however, I noticed that the wiring got warm when the AC was run in "max" mode. I ended up replacing most of the factory 6 Ga with 4 Ga using Anderson SB connector to adapt from the factory 6 Ga to 4 Ga. This not only reduced my amperage draw (no losses in the power cable) but also stopped the cables from getting hot.

I'm running the unit off of 2x Battleborn GC2 100 Ah batteries in parallel. I have a Progressive Dynamics 60 amp charge converter (PD9160ALV) that I use to charge my house batteries and run the Mabru off of shore power. This setup is killer and allows indefinite running of the AC off of 120 VAC shore power.

The reality is that if the van is in the sun, you won't be able to bring the temperature of the van down; however, standing under the AC is amazing for cooling down. Now, if you are in an area where the ambient temperature is high at night, that is where this AC is really killer. It's awesome for removing interior moisture and keeping the interior of the van cool as long as the sun is not beating down on the van. It is also very good at helping keep a pre-cooled van cool.

The AC throttles back periodically, I believe it's trying to conform to a duty cycle.

Overall, I'm happy with the purchase.
Thanks for this feedback on your Mabru AC unit. Regarding your van sitting in the sun, what colour is your van? Besides AC btu output, the van color will have a significant affect on the ability of an AC unit to perform adequately in the sun.
 

Vangrant

Active member
Thanks for this feedback on your Mabru AC unit. Regarding your van sitting in the sun, what colour is your van? Besides AC btu output, the van color will have a significant affect on the ability of an AC unit to perform adequately in the sun.
Definitely. My van is "Silver Grey". My roof rack is black (FVCO Safari Rack) and has black panels, but it actually more or less acts as a heat break on the roof for me.
 

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