Ah, rats, you're right. These are 25 SEER, and they have wall mount evaporators that are 120V, but their ceiling cassette units are 230V.
Here's my plan to install a 230V Mini-Split
- Thread starter HookEm
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Here's another alternative that I'm considering:
Instead of a dedicated 230V inverter, using a larger 120V inverter (from 3KW Multiplus to 5KW Quattro), coupled with a 120v/240V Autotransformer.
1) Plus: charger capacity goes up from 70A to 120A. A/C can run from Shore/Generator power without draining batteries.
2) Con: more weight (+13 lbs), and more expensive (+$870). When running from batteries (i.e., boondocking, which is my main goal), I'd have losses from the Inverter and the Autotransformer.
Thoughts?
Instead of a dedicated 230V inverter, using a larger 120V inverter (from 3KW Multiplus to 5KW Quattro), coupled with a 120v/240V Autotransformer.
1) Plus: charger capacity goes up from 70A to 120A. A/C can run from Shore/Generator power without draining batteries.
2) Con: more weight (+13 lbs), and more expensive (+$870). When running from batteries (i.e., boondocking, which is my main goal), I'd have losses from the Inverter and the Autotransformer.
Thoughts?
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I hope someone technical can weigh-in on this. From a non-technical viewpoint, I think the pros outweigh the cons. PS. I love the way you layout your plans.
I use "Visio"... It's a nice tool.
I wish Victron would publish the "Efficiency" rating on the Autotransformer... Hopefully, it's in the 90s.
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This is just a wild guess, but the additional transformer could decrease the power factor, causing a decrease in efficiency. The inverter will be designed to compensate the power factor for the inductors in the inverter itself, so a 240v inverter might be more efficient.
Is the benefit of a few more SEER worth the additional cost/complexity/potential efficiency loss w/ more hardware? I imagine you're limited in space for panels and batteries which is likely part of your calculus on what works best for your particular situation. I see 21-22 SEER 115V units available.
It‘s also about the inside Cassette units... which are only offered in the higher voltage.
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Ummh... The more I consider the Quattro+AT option, the more I lean towards it.
BTW, I did get some feedback on the "Victron Community" forum, where they claim the Autotransfronmer (AT) should be very efficient, as it's designed specifically for "load balancing (2 legs, split-phase)", "step-up", or "step down" applications.
(but I've not yet gotten an actual Efficiency spec from Victron).
BTW, I did get some feedback on the "Victron Community" forum, where they claim the Autotransfronmer (AT) should be very efficient, as it's designed specifically for "load balancing (2 legs, split-phase)", "step-up", or "step down" applications.
(but I've not yet gotten an actual Efficiency spec from Victron).
I know your rig is much bigger than this (little) project, but perhaps the Mini-Split aspects may translate (I hope).
1) How big (Btu-wise) are your Mini-Split(s)?
2) Is it one outside unit with multiple zones or multip;e outside units?
3) Whats' the typical power consumption from the Mini-Split(s) in contrast with the heat & humidity that you're dealing with?
Thanks!
Yup multi-zone. 1 30k ODU and 2 9k IDU's (I'm upgrading one of those to 12k next week).
In 95 degree humid weather they both run at max and consume about 1000 watts. It'll use anywhere from 250 watts to 1000 depending on the load. (It's 84 now and the AC is using 500 watts to keep it in the low 70's inside). I'll use about 10-15kWh for the mini split (15-20 total) in a given 24-hour period on 95-degree days. My 3.35 kW array can produce 24kWh on a 100% sunny say in the summer. I'm in Indiana now and was in Connecticut a week ago (geography is rated at 5.8-5.9 solar hours per day); my graphs/data are here: https://vrm.victronenergy.com/installation/76892/share/d5bbdd04
Thanks... That provides a useful perspective.
Given my plan: 9K Btu mini-split in a Sprinter Class C RV, based on 9.4KWh of battery and 1700+ Watts of solar, do you think it's realistic to:
1) Run the A/C all night from batteries (say, 6PM to 8AM)
Basically, Can 9.4KWh of battery sustain the A/C and typical nighttime loads? (that's about 530Wh, running batteries down 80% in 14 hours)
2) Then during the day, continue using the A/C while fully recharging the batteries from just 1700+ Watts of solar (say, 8AM to 6PM),
To me, it seems like the 9.4KWh battery may cut it, but the 1700+ of Solar may not be enough! (actually 1900W, with 200W portable),
Also, it seems like Solar may have a chance if the batteries are not as run down (less than 80% would be ideal)... yet again making the case for 780Ah (@12V) being enough.... Are these reasonable assumptions?
BTW, it may seem aggressive or unrealistic to run the A/C 24/7, but my thinking is that by keeping the rig cool the A/C won't have to work as hard over the long haul, and would actually lower the average consumption... But again, is that a reasonable assumption?
That'll depend on your base load (without AC). Mine is about 5kWh/day which is already half of your battery. Add in half of my AC (since your AC is half the size of mine) and you're adding another 5-8kWh/day (all other things such as insulation being equal) on hot days. If you manage to produce 10-12kWh of solar per day, you could still run out unless your reduce your base load way below mine. I'm pretty liberal with my AC usage now that I see I have so much excess; it stands to reason you could use less than me with some effort 
I think you have enough battery for overnight (but not multiple cloudy days) ... you may not have enough solar. That'll really depend on how well your panels perform.
I think you have enough battery for overnight (but not multiple cloudy days) ... you may not have enough solar. That'll really depend on how well your panels perform.
I guess it's safe to say: You can never have too much Solar!That'll depend on your base load (without AC). Mine is about 5kWh/day which is already half of your battery. Add in half of my AC (since your AC is half the size of mine) and you're adding another 5-8kWh/day (all other things such as insulation being equal) on hot days. If you manage to produce 10-12kWh of solar per day, you could still run out unless your reduce your base load way below mine. I'm pretty liberal with my AC usage now that I see I have so much excess; it stands to reason you could use less than me with some effort
I think you have enough battery for overnight (but not multiple cloudy days) ... you may not have enough solar. That'll really depend on how well your panels perform.
Looks like you have put much thought into the power upgrade!
We wanted to do some upgrades to our 2017 Class “C” (Winnebago View 24G).
Chassis for ours would not handle the added weight of all the equipment.
We reduced the plan design to stay within the weight limit.
The OCCC for our RV is 1073 lbs.
Subtracting the weight of passengers, a little onboard water, full LP tank, solar panel & Trojan T-105’s I used to replace the awful NAPA house batteries, left 192 lbs of capacity for dishes, tools, bedding, food, dental floss……..
We wanted to do some upgrades to our 2017 Class “C” (Winnebago View 24G).
Chassis for ours would not handle the added weight of all the equipment.
We reduced the plan design to stay within the weight limit.
The OCCC for our RV is 1073 lbs.
Subtracting the weight of passengers, a little onboard water, full LP tank, solar panel & Trojan T-105’s I used to replace the awful NAPA house batteries, left 192 lbs of capacity for dishes, tools, bedding, food, dental floss……..
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Yes, OCCC it's a major pain point for us.
The plan calls for swapping out (removing) some factory-installed stuff, but there would still be extra weight to consider.
I don't think I have really come to terms with the OCCC limit yet. It is a tiny nagging issue that I have been avoiding. Power, comfort, feasibility first...OCCC second.
Hmmm....Wife or cool solar stuff?
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https://ashp.neep.org/#!/ sliders: 0-13000BTU, 0-13000 BTU, Ducting configuration non-ducted ceiling mount. Should produce 131 results. List View, sorted by SEER: Gree makes two 115 volt models. Specs look like your Blueridge. Those Gree have relatively poor COP. COP may be far more important than SEER. There might additional 115v models with better COP. If you find better COP models, you still have to find out if you can buy them.
I'm trying to plan a system for a 120V 9K BTU 25 SEER mini-split with around 800Ah 12V LIiFePO4. But I also looked at doing 400Ah 24V LIiFePO4, but the costs were always higher, and the system was more complex.
I'm curious. Which parts of the system are a deciding factor in the choice of 24V for your system?
I know 12V vs 24V has been discussed in other threads; however, the specific combination of components and their trade-offs can be crucial either way, so I'm curious.
I'm curious. Which parts of the system are a deciding factor in the choice of 24V for your system?
I know 12V vs 24V has been discussed in other threads; however, the specific combination of components and their trade-offs can be crucial either way, so I'm curious.
The MMPT controllers and DC cables handle half the current, so they're smaller, lighter, and less expensive.
The Inverter/Charger is more efficient at 24VDC (e.g., the charger in the 5KW Quattro is rated at 200A at 12V, and 120A at 24V).
The caveat s feeding 12V loads, which then require 24V/12V converters... but the Victron Orion are very efficient and relatively inexpensive.
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