Designing RV ToyHauler Solar System

[Larry-AK]

I am in the process of designing a 5th Wheel Toy Hauler that will require a 240VAC Mini-Split and looking for a simple solar system to incorporate into the Design. Would the EG4 Offgrid system be something to consider?
I would like to know if a EG4 6000XP, EG4 Indoor Floor Mount Battery, 3000 Solar Panel Array if a feasible configuration. Any pros or cons? Weight is not a problem. The RV will have the typical 50 amp RV external connection and a Generator is available.

 

[chrisski]

You can look at my build and I have the power from solar and batteries to run a minisplit. I have 120 volts, but a 240 volt 3 kW inverter-could power a minisplit with the same panels and battery.

What you’re asking is not impossible, just very hard to achieve. Also super expensive.

A big con for the 6000xp is the high voltages to run. I have found RV shading from parking, AC, vents, etc ruins string production required for high voltages. That’s why I went with multiple charge controllers, and the separate inverter and separate charger.

Weight is not a problem.

As a fifth wheel owner, I disagree and say weight is an issue. If this is non mobile, weight is no issue.

The type of build like you’re asking is between 500 to 1000 lbs and perhaps more.

1500 lbs - 2500 lbs is the weight most RVs have to add weight once tanks are filled.

 

[Larry-AK]

Thank you for your input, I appreciate your input, I didn't think of using an "Inverter" for the Minisplit or the higher Voltages. I have a lot to research and think about. Trying to keep the roof clean for panels and thought about using a 2 or 3-zone Minisplit.
Regarding the weight issue, my builder has stated that my garage payload will be approximately 5000+ lbs (maybe 6000) and my Toy is only 2000 lbs. Still working out the details.

 

[chrisski]

Toy haulers do have more payload then mine.

To get enough power for 2000 watts for the mini split and charging, you’ll need the roof covered with panels and about as many on the ground. Probably at least 2500 watts. That can be changed with accepting using the generator more.

I think a 24k BTU mini split would be good for my 35’ Rv. That would run around 2000 watts until it cooled down, then drop to less, perhaps 800.

My standard 15 k BTU AC pulls about 1550 watts from the inverter, so 1800 watts from the battery.

I’ve also had difficulty figuring where to put the mini split and the head in a fifth wheel. Two or three zones will fix that problem.

Just have to figure out how to get 240 volts to it.

Many have installed a mini split in a smaller RV. Not many have installed a mini split in a fifth wheel. The larger 250 sq foot room and poor insulation requires a larger 240 volt AC especially for cooling the whole fifth wheel.

 

[Larry-AK]

Toy haulers do have more payload then mine.

To get enough power for 2000 watts for the mini split and charging, you’ll need the roof covered with panels and about as many on the ground. Probably at least 2500 watts. That can be changed with accepting using the generator more.

I think a 24k BTU mini split would be good for my 35’ Rv. That would run around 2000 watts until it cooled down, then drop to less, perhaps 800.

My standard 15 k BTU AC pulls about 1550 watts from the inverter, so 1800 watts from the battery.

I’ve also had difficulty figuring where to put the mini split and the head in a fifth wheel. Two or three zones will fix that problem.

Just have to figure out how to get 240 volts to it.

Many have installed a mini split in a smaller RV. Not many have installed a mini split in a fifth wheel. The larger 250 sq foot room and poor insulation requires a larger 240 volt AC especially for cooling the whole fifth wheel.

Thank you, your input is helpful. Deciding on the correct of MiniSplit is the question, recently I read it's better to slightly undersize the unit. I suspect it would keep the inverter more in the idle range and keep from cycling completely off, thus preventing a large current draw on start ups. I need to do more research.

 

[OTRwSolar]

. . . Deciding on the correct of MiniSplit is the question, recently I read it's better to slightly undersize the unit. I suspect it would keep the inverter more in the idle range and keep from cycling completely off, thus preventing a large current draw on start ups. I need to do more research.

A typical mini-split has minimal inrush/startup current (LRA). We have an 18k (240v) minisplit that only has 25a of inrush. A typical 13.5 - 15k RV rooftop a/c unit can have anywhere from 50-70a of inrush.

As for sizing a mini-split, if in doubt go slightly larger. The beauty of an inverter equipped mini-split is its ability to vary its btu output to meet conditions. If necessary, it can throttle down and still produce a constant heating/cooling output easily---no concerns about "short-cycling" and failing to dehumidify properly. If you purchased an undersized mini-split, you gain nothing---you simply end-up with a unit that will not provide enough cooling/heating under worst case conditions. A properly-sized or slightly oversized mini-split can do it all.

 

[chrisski]

If this is a Toy hauler, where would your compressor sit? Typically they go on the 4” bumper in the rear.

I read it's better to slightly undersize the unit.

I’ve heard that and I won’t bet my money and time on this.

I’ve also been assured a 12k BTU 120 volt mini-split would cool better than my 15K BTU stock AC.

I’m not willing to be the first kid on the block to put a 12k BTU AC in my RV when a 15k BTU doesn’t even keep up in 90 degree weather for a 250 sq foot area.

If I were to do it, I’d like an 18k BTU 240 volt 2 head unit with one above the main entrance door in the front and the other above the opposite wall in the rear.

Coming soon is this inverter rooftop AC, a not yet released 18k Furion Chill. I think it pulls as much or slightly less wattage than my 15k BTU and is a drop in replacement.

https://corporate.lippert.com/products/rv/ac/furrion-chill-cube