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Mini-Split heating/cooling units

Post in 'The Green Room' started by fossil, Aug 24, 2012.

  1. Highbeam

    Highbeam Minister of Fire

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    That is not a standard unit. We're not talking about the odd, ultra expensive, rare, option. That's like saying that this here woman has three legs so you shouldn't complain about the rest of the women with two!

    The good news is that these companies realize how stupid the indoor units look and some are trying to make an effort to fix it. I think that as time goes on, you will see more attractive options available in the main product line. It is crucial to the survivial and even the broad acceptance of this technology.

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  2. begreen

    begreen Mooderator Staff Member

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    The indoor units look ok, better than a lot of window units. I've seen them in many homes, from classic old farmhouses to contemporaries. I don't think there'll be a major industry change anytime soon.
  3. ROVERT

    ROVERT Member

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    I have to say I'm in the camp that is of the opinion that the standard indoor units look pretty bad hanging on the wall. I'm not saying you can't get used to them, but they are definitely not aesthetically pleasing. To me they give a room that "motel" vibe. They are much better than they used to be though.

    I do think there will be an industry change. I think products like Art Cool (which isn't much more expensive these days) and ceiling cassettes will become more of the norm. Technology is being developed that means you don't have to have a box hanging on the wall to enjoy the benefits of a mini split. Twenty years ago mini split indoor units were four times the size of what they are today and were typically mounted low on the wall, which inhibited furniture placement. They have become much less obtrusive and I think that trend will continue. I think multi zone mini splits with ceiling cassettes will begin to see a lot of use in new construction.

    Everything continues to get smaller. I see no reason to think that we'll keep mounting these largish appliance looking boxes on the wall when it will not be necessary to do so.
  4. begreen

    begreen Mooderator Staff Member

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    In warmer climates they often are mounted high on the walls. That makes them less obtrusive, but less ideal for heating. Some companies also make these units with indoor handlers that hide in the attic, false ceiling or basement and then get ducted. For me the thing that make a place really get that motel vibe is cheap Walmart art. A magic fingers bed in the living room will really do it too.
  5. Highbeam

    Highbeam Minister of Fire

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    The headboards that are bolted to the wall as to prevent "slapping". But I don't hink hotel, I think travel trailer. The A/C unit in a travel trailer is flush mounted to the ceiling and even less ugly than this big herking inside unit of the minisplit. I don't want to feel like my house is a trailer.
  6. begreen

    begreen Mooderator Staff Member

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    No problem, don't install one. It's your home and how it looks to you is important. My wife made the same argument against putting in a Mansfield. She won.
  7. ROVERT

    ROVERT Member

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    Maybe they'll start making them look like tastefully designed C/I wood stoves. You could bring the line set in through the faux smoke pipe. You'd still have to sneak the condensate line out somewhere.
  8. begreen

    begreen Mooderator Staff Member

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    You could do that via the OAK.
    PapaDave likes this.
  9. Woody Stover

    Woody Stover Minister of Fire

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    Yeah, we can't leave in the Winter unless we have someone come by to stoke the stove. Pets would still have to be fed though...
    This Summer wasn't too bad since the humidity was low, but I'm about ready for a little AC to get us through the normal bad stretches of heat/humidity.
    Should be easy to do here; 720 sqft main room and a 270 bedroom, one level.
    Wow, those HomeDespot units are dirt-cheap (probably with good reason.) Seeing the Fred Couples ads for the Mitsu, I figured they would be two or three thousand anyway...
  10. sesmith

    sesmith Member

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  11. Highbeam

    Highbeam Minister of Fire

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    Now that's not very nice. Stating the obvious isn't your normal MO.

    A cast iron faux stove indoor unit, now there's a million dollar idea.
  12. fossil

    fossil Accidental Moderator Staff Member

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  13. Thomas Anderson

    Thomas Anderson Member

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    Low hanging fruit: potted shrubs/vines on the balcony with sufficient foliage to cast shade, high albedo curtains to reflect light back out, or low-e window films.

    Since you said humidity is not a problem, a swamp cooler would be a more efficient method of cooling than an air conditioner or heat pump. Even just a simple water feature in the room (e.g. a small copper wall fountain) may reduce the temperature several degrees.
  14. begreen

    begreen Mooderator Staff Member

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    Sorry, didn't mean to challenge. I've learned from this thread that some folks just plain don't like the looks of these things. My comment was meant to endorse that feeling. If you don't like it, that's fine. That's why I suggested earlier that there are alternatives including a hidden air handler that can be ducted. Or, perhaps one could remove the cowling and build the guts into a custom enclosure that fits the home decor? Maybe a wood or stone surround?
  15. begreen

    begreen Mooderator Staff Member

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    Not a working solution in a high humidity environment or climate. It just adds insult to misery.
  16. Iembalm4aLiving

    Iembalm4aLiving Feeling the Heat

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    We've got 2 Mitsubishi Mr. Slim split systems installed in our house (which has hot water heating) and we've been thrilled with them. They're quiet and amazingly efficient. I recommend them highly.
  17. fossil

    fossil Accidental Moderator Staff Member

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    Do you look to them for mostly heating or mostly cooling, or pretty much equally both?
  18. Iembalm4aLiving

    Iembalm4aLiving Feeling the Heat

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    My Mr. Slims are the cooling only units. My hot water heating system has 3 zones, so I already had the ability to turn down areas of the house not being used when it came to heating. A/C was my main concern, as not having any air ducts in the house would have made installing central air super expensive.
  19. velvetfoot

    velvetfoot Minister of Fire

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    It's good to know they're quiet. Hard to match the tick tick noise of the baseboard radiators, but then, for me, the source of that tick tick noise is the oil-fired boiler.

    Was it tough running the electric? Did each unit need to have a circuit run? I'd have to get to the second floor.
  20. ROVERT

    ROVERT Member

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    Each ductless system should have its own circuit. The electric goes up the outside of the house with the lineset and condensate line. Unless you are trying to run everything inside the walls (which would typically be cost prohibitive in anything but new construction or an extensive remodel), you don't have to worry about getting the power to the indoor unit. There are a variety of configurations that require different supply circuits. Some units are 220 v, some are 110 v, and some use low voltage air handlers. The only circuit necessary, though, should be an appropriately sized circuit to the outdoor unit.
  21. velvetfoot

    velvetfoot Minister of Fire

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    Thanks! I didn't know that. And, the outdoor unit would probably be at ground level, more accessable for wiring.
  22. fossil

    fossil Accidental Moderator Staff Member

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    That's interesting about your units being "cool only". I'll have to look into that, as cooling is what I'm most interested in. My home has an installed forced air heating system, but adding A/C to it would not only be very expensive, but also a waste, as I'm only ever interested in a room or two being comfortable. Thanks for that lead. Rick
  23. RustyShackleford

    RustyShackleford Minister of Fire

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    Why ? This is a big issue for me, because I want to add a mini-split for an addition. I'd put the compressor (outdoor unit) near the compressor for my existing heat-pump, which is on a 60-amp circuit (from an old inefficient HVAC) but has only 35-amp labeling and 16 amps running current. So the 12,000 btu/hr mini-split I'm looking at (20-amp breaker and 5.5 amp RLA) could EASILY live on the same circuit. I hate to run another circuit, because it's far from the breaker box and I'm short on spare slots. When the heat-pump dies (it's 15 years old and only 11 SEER) I'd add a second mini-split and that'd handle my whole house, hopefully. If it really MUST be on a separate circuit, I suppose I could run a sub-panel off the 60-amp circuit.
  24. ROVERT

    ROVERT Member

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    So you're planning on running a 12 wire right off of the 60 A circuit disconnect to run a mini split? Breakers are used for a reason, I would suggest the sub-panel. The mini split will likely specify a maximum breaker size of 25A, that shouldn't be exceeded.
  25. RustyShackleford

    RustyShackleford Minister of Fire

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    Thanks for responding. The circuit is controlled by a 60 amp double-pole breaker in my main box. I'd run the 60-amp rated wire to two fused service disconnects, one for the old heat-pump (an existing one with 35 amp fuses) and one for the new mini-split (with 20 amp fuses, as spec'ed for the mini-split). Either daisy-chained per usual wiring techniques, or via a blind junction box in the crawlspace; whatever I do, I'd still use 6ga wire, since of course it's a no-no to have any wire on the circuit that can't handle the breaker-size current

    If that isn't kosher, I'd do as you suggest and run a sub-panel off the 60 amp breaker. It'd have 35 and 20 amp breakers for the two units. Hopefully I can position the sub-panel so as to be close enough to both compressors - I think the service disconnect only needs to be "within sight" and I can easily achieve that. I wonder if it would be a problem that 35+20 is more than 80% of 60 ?

    Also, the wire going from the 60-amp breaker in the main box to the disconnect for the existing heatpump is 6-2 (IOW, no neutral). I know subpanels are required to keep neutral and ground separate, but I'd have no neutral. Neither does the existing heat-pump have a neutral (just two hots), and it turns out the mini-split has only two hots and a ground also. So hopefully it's ok not to have separate neutrals and ground in the sub-panel if those are the only loads.

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