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Community and Q&A

Hiding a ductless head

CarsonB | Posted in Mechanicals on

Hello gba,
Here’s my idea to hide a minisplit head, please critique and tell me why this won’t work.  Keep in mind that the ducted install was a lot more expensive and the floor units are large and just don’t look good imho.  

1.  Mount mitsubishi head 18 inches from floor.  I realize this goes against the manual.  Will only be used for heating.  See https://www.buildinggreen.com/blog/7-tips-get-more-mini-split-heat-pumps-colder-climates

2.  Inset unit into wall as far as allowed.

3.  Build buffet table to go over unit, route grill into the buffet top for airflow.  EDIT:  I meant console table with no face or bottom to block airflow.  Something like this:  https://www.amazon.com/Convenience-Concepts-Northfield-Console-Espresso/dp/B002YD8E36/ref=mp_s_a_1_12?keywords=console+table&qid=1583516177&sr=8-12

4.  Make sure no one ever places papers on buffet table…

 

crazy?  Hvac contractor was concerned about the air bouncing off the floor and short circuiting the airflow.  Sounds ideal though for hiding it, I don’t think anyone would ever notice it.  

https://www.ecomfort.com/Mitsubishi-MSZ-EF09NAB-U1/p67942.html

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Replies

    1. CarsonB | | #8

      I liked this one: https://www.pinterest.com/pin/562105597243381894/
      wouldn't the louvres on such a setup affect the directional airflow of these units though? Does mitsubishi have guidance on these? It seems that the horizontal slats would affect it drawing air from above and blowing that air across the floor as designed?

  1. Yupster | | #2

    You need a grille for a supply AND return, and they need to be separated, otherwise you'll just be recirculating air you just conditioned, greatly reducing the efficiency (and effectiveness!) of the unit. The grilles will probably need to be much larger than what you are imagining, to prevent a pressure drop large enough to alter the airflow over the indoor unit. These are carefully calibrated units, mess up the airflow, you mess up the unit. You also need access for maintenance, both for the inevitable mechanical breakdown and the regular filter cleaning.

    Better options I've seen involve putting it up high and putting a 12" deep floating shelf directly below it. Place some nice knick knacks either side, the unit just fades into the background.

    1. CarsonB | | #6

      I used the wrong term: console table. So no front or bottom. Basically just the reverse of the shelf you described. The issue with the shelf is that the wall in question are stairs and there isn’t a really good spot for it up high. https://www.amazon.com/Convenience-Concepts-Northfield-Console-Espresso/dp/B002YD8E36/ref=mp_s_a_1_12?keywords=console+table&qid=1583516177&sr=8-12

      1. Yupster | | #9

        Ah, gotcha. That's a much better plan.

  2. User avatar
    Walter Ahlgrim | | #3

    If you want a floor mounted head you could buy one.
    Have you seen this article?
    https://www.greenbuildingadvisor.com/article/bruce-harleys-minisplit-tips

    Walta

    1. CarsonB | | #4

      Sure, but as I said they just don’t look very good imho. I think it’s a shame they update the wall units a lot, but the floor units get few updates.

  3. User avatar
    Dana Dorsett | | #5

    It will be a lot easier to get the air flow correct using a floor unit. If you're going to build
    cabinet or table type enclosures around them who CARES if they"...just don’t look good..." ?

    1. CarsonB | | #7

      I was concerned about building an actual cabinet for airflow reasons, so it’s still visible. Though you are right, the hope is that no one (esp wife) will notice it. Perhaps I could paint it black?

      1. User avatar
        Dana Dorsett | | #10

        >"Perhaps I could paint it black?"

        I know Mitsubishi high-wall MSZ-EF and LN series can be ordered in a black finish. Not sure if they have black floor units though.

        https://innovations.mitsubishi-les.com/en/m-series/msz-ef

        https://innovations.mitsubishi-les.com/en/m-series/msz-ln

        LG has some black high wall units too.

        https://www.lg.com/pa_en/residential-air-conditioners/lg-ARTCOOL-INVERTER-VR182CE

        1. CarsonB | | #15

          Yeah thats the wall unit I was looking at, I think the black looks great. I haven’t found a black floor unit. No one local here seems to want to deal with lg unfortunately.

  4. Brendan Albano | | #11

    What ducted approach were you looking at? What was the cost difference?

    I'd be curious about the cost difference between a ductless wall unit, and a very simple installation of something like this: https://www.fujitsugeneral.com/us/products/split/s-duct/index.html

    For example, the bottom left example in the following diagram is basically the effect you are describing, but using a product that is designed to be installed in that manner: https://www.fujitsugeneral.com/us/resources/images/products/split/s-duct/top/img-flexible.png

    1. CarsonB | | #12

      It was huge. Its apples to oranges because the contractors specified different units, I should go back to the one that quoted the Ductless units and get one for the same condenser. It was almost 20k. To put labor costs in perspective, it’s over 2k just to install a branch box so I’m going with the 30k hyper condenser that doesn’t need one.

    2. CarsonB | | #13

      I had never seen one of those mounted like the bottom left one, that looks great. The concern I have though is that the looks like the opposite of what I’d want for heating right? The return is on the floor and the supply is directed up?

  5. CarsonB | | #14

    The notion I’m getting is it would be better to get a floor unit, put it behind the wall, and install grills at yhe top and bottom and hope the louvres won’t affect airflow. You would think they would just build a unit like this for the american market. Would I be losing anything with this approach vs the wall unit which has directed “3d” tracking? It is in a large room.

  6. Keith Gustafson | | #16

    Why not go with a ducted minisplit?

    1. CarsonB | | #25

      Very high quotes

  7. Keith Gustafson | | #17

    So, and the reasons not to do this:

    You get used to them, in a house full of stuff, they are not a focal point.

    If things go sideways and it doesn't work, no one will be able to help you

  8. Rick Evans | | #18

    To each his own... I am amazed that some people balk at the site of a mini split head but willingly accept an ugly hissing radiator, a dull grill, or an underperforming baseboard panel.

    I celebrate our mini split head as it is so efficient and practical that it transcends aesthetics. It is a thing of beauty in its own right.

    1. George Smith | | #19

      The same conversations probably took place when ugly hissing radiators came on the scene hence, radiator covers. Now, they're ignored as part of the background just as mini split heads will be when they become more common.

    2. Malcolm Taylor | | #20

      I agree. Household appliances don't look great even when dressed up with stainless steel. I like to see the source of my heat. Don't mind mini-splits at all.

    3. User avatar
      Michael Maines | | #21

      Not only willingly accept--I've had many clients who view cast iron behemoth radiators as a positive feature. Most people I've talked to who have wall-mounted mini splits say that they quickly forget they're there.

    4. CarsonB | | #22

      I agree they probably will go unnoticed for the most part, but I’m not the one objecting to it. I also don’t view objections to it as unreasonable- we don’t have any other white plastic appliances. From my view I’m already putting in a lot of effort making nice custom cabinets to hide all sorts of things so one more isn’t a big deal. I think the attitude of it being a thing of beauty because it is so efficient probably only exists in the tiny niche of us nerds and engineers that frequent these forums. Also, as a green initiative getting ductless minisplits in every home is probably one of the biggest impacts we can make and this is a common objection I hear.

      1. Andy CD Zone 5 - NW Ohio | | #23

        Carson, aesthetic considerations are tremendously important, but they are not absolute and fixed; they are a moving target. If you are making your own cabinets, would it not be straightforward to enclose a mini-ducted unit (i.e. "floor unit") into the end of a cabinet run, either uppers or lowers? It would take up 8" of space. If you do the install, maybe your HVAC person can just handle the lineset and commissioning for a much more reasonable price. Alternately, have you considered a ceiling cassette?

        1. CarsonB | | #24

          There are several issues:
          1. Miniducted units are too large to fit horizontally in a cabinet.
          2. I dont have a ceiling to put a cassett due to timberframe house. I have some soffits in the kitchen but the stairs are more centrally located to the main living space. I’ve also heard the cassetts need to be accessible from above.
          3. Im pretty handy, but I don’t know how diy friend creating efficient ducts are.
          4. Finding an hvac guy that will just commission someone else’s install.

          I could see mounting the ducted unit vertically under the stairs with the return connected right into the wall, with sort of a round c shape duct put in so the supply bends 90 degrees to a grill at the flooor, but is this wise? I’ve never seen it much less know if I should attempt such a thing.

          1. Andy CD Zone 5 - NW Ohio | | #26

            Carson,
            1. I was thinking of the unit mounted vertically, taking up approximately the space of a 9"-wide lower end cabinet.
            2. Maybe ceiling cassette isn't workable in your space, but FYI it does not need access from above.
            3. I'm no HVAC expert, but that's the beauty of mini-ducted. You can literally have NO ductwork, or just a simple manifold coming off the unit. Keep it big and very short. Not rocket science, easy to DIY with parts from the box store, some self-tapping screws and foil tape.
            4. Yeah, that's a problem. But offer a deal: you'll buy the unit at full retail, and pay their full labor rate for commissioning. (I tried several places before a manager shrugged and said, "sure, why not!")

            Your idea for under the stairs sounds do-able. Mini-ducted units are perfect for in-wall mounting. If you post sketches I bet people will help refine the design.

          2. CarsonB | | #29

            thanks Andy. Unfortunately I looked some more into it and, according to a post I read from Dana, only the fujitsu units can be mounted vertically? According to fujitsu's website there are no installers in my area. I think I can still do something similar with the mitsubishi, just the ductwork would get a lot more complicated. I'll attach some sketches in my next message here.

            1. I think the problem here is that the units are nearly 50 inches in the longest dimension and would really take up that entire cabinet due to cables, ducts, etc. So you are either talking about a floor to ceiling utility cabinet or turning it on its side and taking up nearly 4 ft of lower cabinets. I actually thought about running one in the bottom of a cabinet and having the back go out through a wall behind the cabinet into a builtin, but that seemed way too complicated.
            2. good to know.
            3. This may indeed be a better plan than DIY'ing custom grilles with a recessed floor unit. Still, intimidating for someone with no hvac experience.
            4. that is my dream scenario. HVAC folks are busy here. Maybe I need to ask around hvac supply stores for some clandestine maverick with a free saturday.

            "1. I was thinking of the unit mounted vertically, taking up approximately the space of a 9"-wide lower end cabinet.
            2. Maybe ceiling cassette isn't workable in your space, but FYI it does not need access from above.
            3. I'm no HVAC expert, but that's the beauty of mini-ducted. You can literally have NO ductwork, or just a simple manifold coming off the unit. Keep it big and very short. Not rocket science, easy to DIY with parts from the box store, some self-tapping screws and foil tape.
            4. Yeah, that's a problem. But offer a deal: you'll buy the unit at full retail, and pay their full labor rate for commissioning. (I tried several places before a manager shrugged and said, "sure, why not!")

            Your idea for under the stairs sounds do-able. Mini-ducted units are perfect for in-wall mounting. If you post sketches I bet people will help refine the design."

          3. CarsonB | | #30

            sketchy sketches

  9. Keith Gustafson | | #27

    As far as installing ducted units

    closet ceilings, hall ceilings, transition areas where as drop in height is not noticable, under stairs.

    The biggest issue with DIY installs is warranty.

    I have 3 self installed[mitsu] units in my house, 10 years zero failures. One[mitsu] in last house, 6 years before selling, another no name 2 years, one no name at work 4 years. The one at work is the only one that I did the refrigerant in.
    42 unit years, if you will, no failures.
    Until installers start treating them on a cost plus basis rather than billing as if installing and commissioning a standard system, it would be cheaper to bet on having to replace a unit without warranty help than pay an installer

    It is mostly carpentry, and you already have an electrician in house. ....

    I am willing to be it is only the one that would be in the public space that bugs you, and worst case if you need -14F ability a Mitsu hyper heat is 4 grand from acwholesalers. If you can deal with -4, it would be half that.
    I have a problem pay anyone 10 grand for the days work to install it, but I'm a cheapass.......

    1. CarsonB | | #28

      I would love to get a total DIY install, but I don't want to tackle refrigerant and the hvac people here are so busy they barely reply to me at all much less are interested in just commissioning a unit. The units I'm getting are the 30k mistubishi hyper heat and 2 18k indoor units. Yeah, on ecomfort the total cost is only about 5k. The cheapest quote from an installer I've gotten is 8600. That's about 3500 for one days labor, but then again at least I get warranty and less hassle, still saving a ton vs the other quotes I've gotten without explicitly demanding a specific setup.

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