LG vs Mitsubishi Mini Split Heat Pumps

H2SO4_guy
H2SO4_guy Solar Expert Posts: 213 ✭✭✭
in Off Grid Solar & Battery Systems #1
The goal is to cool, and possibly heat a bit with excess power, a 175 sq ft (One room shanty) living quarters built inside of a barn. The outside unit will probably sit inside of the barn but outside of the living quarters. It is off grid so efficiency is very important. The best choices I have found so far are:

Mitsubishi MUZFE09NA mini split heat pump with 9000 BTU, 26 SEER and runs $1517.99 delivered.

LG LSU090HYV mini split heat pump with 9000 BTU, 28 SEER, and runs $1329.00 delivered.

They are both heat pumps with inverter technology and are supposed to work down to around 5 degrees, but I don’t know how much heat they will extract when it is colder, but they will probably live inside of the barn, so they will be protected from the elements and wind, however it does get cold in there.

It would be nice to use excess solar energy on heating the living space once the batteries are full, otherwise the power is lost. Heating water is also an option, but I haven’t worked out the details on that.

There will be a backup propane heater if this option is using too much power.

This will be on an Outback VFX-3648 inverter and thanks to NAWS Earth day sale, there is a 220 volt 6000 watt transformer on the way. Any insight on this would be appreciated, especially using them off grid.

Thanks,

Skip
12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #2
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    Hi Skip,

    Have you seen this Thread?:

    http://forum.solar-electric.com/showthread.php?5104-Sanyo-mini-split-AC-(inverter-variable-speed)

    Must admit that I did not study each of those 55 pages to see if you posted. FWIW, Good Luck, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #3
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    Interesting that the LG is 28 SEER, I think that is a new winner in the top efficiency category.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • Ralph Day
    Ralph Day Solar Expert Posts: 1,022 ✭✭✭✭
    #4
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    I have a 12000btu Mitsubishi heat pump, love it!

    One concern I'd have is, if your outside compresser unit is inside the barn, and your living space is inside the barn, you're going to be extracting heat from the living space and dumping it just outside the living space. Better if the compressor is outside the barn, you'll get better efficiency when there's more temperature differential between the air handler and the compressor.

    |Ralph
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #5
    Re: LG vs Mitsubishi Mini Split Heat Pumps
    Ralph Day wrote: »
    I have a 12000btu Mitsubishi heat pump, love it!

    One concern I'd have is, if your outside compresser unit is inside the barn, and your living space is inside the barn, you're going to be extracting heat from the living space and dumping it just outside the living space. Better if the compressor is outside the barn, you'll get better efficiency when there's more temperature differential between the air handler and the compressor.

    |Ralph

    Totally agree!
    Reminds me of a convo I had recently with an installer of heat pump water heaters. When they're installed in a basement, they tend to turn the basement into a refrigerator, and the problem has become so widespread that they are having to go back and install vents and air ducts to bring in outside air to the heat pump, then exhaust the freezing air it emits, back outside.
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  • H2SO4_guy
    H2SO4_guy Solar Expert Posts: 213 ✭✭✭
    #6
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    The barn is 4000 sq ft with 14' walls and 20' to the peak. The walls of the one room shanty are 2x6 with R-21 insulation on the inside and the single exterior wall has R-30 fiberglass batts. I thought the volume of the barn would be enough to be alright and the compressor would last longer if it was not exposed directly to the elements.

    Thanks for everyone's insight, it is such a cool brain trust here.

    Skip
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
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  • Ralph Day
    Ralph Day Solar Expert Posts: 1,022 ✭✭✭✭
    #7
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    Sounds like a big enough barn your original idea might fly. If you do it that way and find the barn air volume is warmer than the outside air, just open a door and or window. Some airflow through the barn would remove the heated air nicely. Is it a wood sided barn? Can you see daylight between boards or are you in a steel sealed up barn? At any rate, move the air through/out of the barn.

    Ralph
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #8
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    I use to have a warehouse that had a office and clean room that had the A/C condensing units in the high bay overhead that never had a issue. I can't see where a barn would be a problem, everything does have a limit.
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  • H2SO4_guy
    H2SO4_guy Solar Expert Posts: 213 ✭✭✭
    #9
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    The barn is an old Armco Steel I-Beam structure with metal siding and a very small amount of insulation for the roof. I do intend to put a solar powered fan on the in a high point to exhaust some of the hot air. There is plenty of airflow because it is not totally tight.

    Vic: Thanks for the link ont he mini split stuff, interesting reading. I think I will buy the 26 SEER Mitsubishi heat pump for the living quarters, it looks pretty neat.
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
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  • Ralph Day
    Ralph Day Solar Expert Posts: 1,022 ✭✭✭✭
    #10
    Re: LG vs Mitsubishi Mini Split Heat Pumps

    Good choice, I really like my Mits unit. Cools and heats off renewables or utility power.

    Ralp;h
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