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Mini-Split HVAC System (Pros versus Cons)

Amit R
5 years ago

We are building a two story 5000 s.f. home. One of the solar/HVAC vendors is recommending a Fujitsu mini split system. It appeals to us in that most of the time we will be in one area of the home. The system will have 7-8 zones. We live in a warm climate north of Sacramento. Besides the additional cost what are the disadvantages of going with this type of system versus a traditional system.

Comments (23)

  • User
    5 years ago
    last modified: 5 years ago

    Well, this is kind of a yin-yang heating & cooling system. It is far more energy efficient and in theory is supposed to cut energy loss by 30% versus the ducted style systems. Then you can also control the various zones with great accuracy.

    The downside for me is that personally, I feel it gives the room a 'Motel 6' vibe. Its not typically seen here (Northern California), so maybe that is why I have that reaction to it. Maybe if this was a guest rental, I'd say ok, but otherwise it say 'cheap' even though it may not be. The other downside with the system, is that you have a 2-story, but no accommodation (venting and fan) to push upstairs warm air back down to the 1st floor during the winter-time. Will that drive up heating costs somewhat?

    If you go ductless, you will have some expensive mountains to move to install a conventional system

  • PRO
    Austin Air Companie
    5 years ago

    Repair & Maintenance costs are probably the biggest consideration. The more equipment you have the more repair & maintenance costs will be in the future. Average life span is about 15 years. Skip the maintenance and the life span will likely drop to 10-12 years, typically just after the manufacturer's warranty runs out.

  • sktn77a
    5 years ago

    Minisplits work well in small home or homes with open plan space but not in a 5000sq ft traditional home. Go with a regular split system. If your home is 2 or more levels, go with 2 or more systems.

  • Judy Mishkin
    5 years ago

    they really look pretty bad. friends put them in their vacation house and every time i sit in their living room i just wonder what they were thinking. honestly i'd rather sweat.

  • Bruce in Northern Virginia
    5 years ago

    Many of the mini-split vendors now offer a ceiling cassette installation that is similar to these. https://www.pioneerminisplit.com/collections/cyb  This makes the "head" look much more like a traditional vent.

    However, 5000 sq ft is much larger and more complicated than I've seen a mini-split system. I think that two traditional ducted heat pumps would be much more typical. That allows you to zone it into top and bottom floors, which is usually the biggest temperature differential.

    Just make sure they also include multiple cold air returns, including both the main living areas and each bedroom. You want to keep air circulating effectively, and the extra cold air returns will help.

    Bruce

  • mtvhike
    5 years ago
    last modified: 5 years ago

    About 10 years ago I was considering putting central AC in my 120 YO 2 story home. About 800 square feet per floor. The contractor who came out could have done either central, or two mini-splits. There would have to have been with two central systems (one in the basement and one in the attic) because there was no way to run the ducts between the floors. For that reason, he recommended two mini-splits. I ended up not doing either.

  • User
    5 years ago

    Disadvantages of Solar AC . Weather dependent


    The poster lives in Sacramento, CA. I live in the SF Bay Area, CA. Basically, she has similar sunny weather to ours. She will not have to worry about any lack of sunshine. Rather, she will have too much sunshine; meaning that large eves to provide shade and wrap-around shade structures are probably going to be on her 'to do' list.


    She lives in a city that has promoted tree planting city-wide to cut down the sun and heat.

  • Amit R
    Original Author
    5 years ago

    Thanks for the feedback. I should have mentioned that most of our system will be ducted. We will only have two ceiling cassettes in secondary areas. Below is a better description of the system. Any feedback would be greatly appreciated.


    1.) Fujitsu 5 ton VRF system to feed the main area's downstairs and the guest room. Includes 5 ton high static ducted air handler in the crawl space to feed main entry, great room, kitchen, dinning room and guest suite.

    2.) Fujitsu 4 ton Halcyon system to feed two bedrooms 2 bathrooms, gym and bonus room. 18K ducted air handler in the crawl space to feed the two bedrooms / bathrooms. 12K ducted air handler to feed bonus room. 9k ceiling cassette air handler to feed gym.

    Install

    3.) Fujitsu 3 ton Halcyon system to feed master suite, bedroom and sitting area. 18K ducted air handler to feed the master bed and bath. 12K ducted air handler to feed bedroom. 9Kceiling cassette to feed upstairs landing / sitting area.

  • User
    5 years ago

    Amit- I realize this is your house, and you can do whatever you want with it. But you really need to reconsider this AC system. In this area, people will look at your AC system as if you went cheap and installed a Motel 6-looking AC system; no matter what you paid. You could have a really difficult time when in comes to resale. Please, do yourself a favor....please talk to local Realtors and get their opinion on what your AC choice will do to your potential resale value and possible reduction in your pool of buyers at resale time.

  • Bruce in Northern Virginia
    5 years ago
    last modified: 5 years ago

    I would have to agree with gluscombe, most folks don't know that mini-splits are a much more advanced A/C system than a typical cheap motel PTAC that comes through the wall. They just look at the exposed head mounted on the wall in the room and conclude - must have been installed because its cheaper.

    For appearances in the room, it will help a lot if you use ceiling cassettes and a wall mounted thermostat, since that looks much more like standard A/C.

    Bruce

  • roarah
    5 years ago
    last modified: 5 years ago

    If I understand correctly you are doing a ducted system in most areas and a few ductless evaporators in harder to reach areas. Both your ducted and ductless evaporators will be connected to the same outside condenser. This sells well in my area. It is what I have.

    Bedrooms are ducted with an evaporator in attic and downstairs we have a ugly single wall unit in a inconspicuous corner. Both evaporators are connected to just one outside condenser.

    Honestly the vents in the bedrooms initially bugged me more than the wall evaporator which surprised me. I kept thinking there was a bat on my bed room ceiling. I also like that instead of multiple ugly vents and returns in all main floor rooms I can cool as well with only a single room having a single ugly evaporator.

    We did this route because my basement is a finished daycare area which could not spare the headroom to add ducts and we have wood and tin ceilings in my 1920s main floor which I did not wish to cut into nor did I wish to lose any closet space in my limited storage house. I looked into high velocity but the needed duct work, although smaller than conventional, was still pretty bulky and in retro fitting cases extensive and invasive work to my plaster walls and tin ceilings was needed and I could not justify the low seer ratings.

    The seer ratings are great for my system and the one outside unit is so much smaller and quieter than my neighbor's ducted carrier unit. I am in a very high COLA in a Connecticut NYC suburb and this setup is the new norm and is listed as a selling feature above conventional hvac but green is hip here and people sell million plus homes with minisplits and solar panels on front elevations often in upgraded older houses. I used Mitsubishi.

    younger buyers vs older will make or break your system's popularity during resale I believe. Younger want green efficiency and shun older energy wasting systems today.

  • Jake The Wonderdog
    5 years ago

    Yeah, so I agree that a big drawback of minisplits is the interior head unit... but several of you didn't even read the fact that that the OP is using ducted and ceiling cassettes.

    Austin Air Companie - do you have any real data to back up the "greater mechanical complexity / higher maintenance" argument? Looking at most of these head units they are pretty simple - a DC brushless motor, some thermistors and control electronics. I think I even saw some condensate pumps and drain backup sensors on some of the units.

    The mechanical argument reminds me of when cars started going to electronic ignition and fuel injection. Carburetors and points really sucked -- they did a terrible job, were unreliable and high maintenance -- and yet mechanics bitched about the new technology. Sure, the first round of it was buggy... but now cars perform better, get better mileage, lower emissions, MUCH more reliable and need a tuneup only every 100k miles -- all using vastly more mechanically complex systems than what they replaced.

  • cgelle
    5 years ago

    Living in PA, we have a 60's built ranch home with no ductwork. My husband had one of these systems put in this summer (Fijitsu wall mounted system) to cool our main living area. It works great. It is quiet and works very well cooling most of the house although we only needed it for living/dining/kitchen. I had hoped for the best when I reluctantly agreed because I HATED how it looked. I had seen these units in other peoples homes and hated them then. People (especially contractors) assured me that I would get over this. It has been since June and I still hate how it looks. When friends and family (admittedly mostly female) see this unit, their first reaction is negative on how it looks. They try to be nice about it but when I ask their honest opinion, they say it is ugly. I really regret having this installed. The few short months that we use it was not worth the eyesore it is in our house. I am trying to come up with ways to hide this beast for the 8 or 9 months of the year that we don't use it. I am writing this only to forewarn anyone who has concerns about installing these units because of the looks. My advice would be if you have white walls and high ceilings, then this would likely be less noticeable. If you have lower ceilings like I do and have a wall color other than white or light, this is going to be noticeable. Also, I would suggest do whatever you can to find a wall that is not a focal wall to install this beast. My was installed on a focal wall which only adds to the problem.

  • Jake The Wonderdog
    5 years ago

    britlitfan


    You should know that there are indoor units that don't look like that.

    There are units that go in the ceiling - that are still kinda ugly - but not as bad.


    There are also units that allow for more traditional looking venting.


    I think that these companies have a challenge to make the indoor unit more palatable. I see that as a big hindrance to being used in a residential setting/



  • User
    5 years ago

    " I had hoped for the best when I reluctantly agreed because I HATED how it looked."

    Well then I don't have to wait very long. It sounds like I'd be a reasonable candidate for the Fijitsu wall mounted system. All the I have to do is wait 'till my cataract growth is fully completed.

  • PRO
    Austin Air Companie
    5 years ago
    last modified: 5 years ago

    Austin Air Companie - do you have any real data to back up the "greater mechanical complexity / higher maintenance" argument? Looking at most of these head units they are pretty simple - a DC brushless motor, some thermistors and control electronics. I think I even saw some condensate pumps and drain backup sensors on some of the units.

    "I didn't say greater mechanical complexity... I said higher maintenance and repair costs, due to more equipment. " Anything can be fixed, for a price.

    Data? No, common sense, yes.

    Equipment, no matter what kind it is... requires maintenance to some degree. (filters, drain clogs, refrigerant leaks, electrical problems etc all fall under the maintenance umbrella) The more you operate a mechanical device, the more likely it is that it will require maintenance. If you don't do the maintenance this often leads to more failures of the equipment and ultimately replacement. The more equipment you have, the more everything costs.

    How do I know this outside of common sense? Look at what I do for a living.

  • Laurie Tillett
    5 years ago
    I may not be an AC expert, but we had a mini split like you’re considering in our pool house/guest room. What a royal pain in the patootie!!! If someone got impatient and tried to bring the temp down too fast....”punching buttons” the whole thing would just go bellyup and then we would have to call the electrician, yadayadayada ..... I don’t care how much they’ve supposed to be improved, never again!!!
  • LynneO
    5 years ago
    I live in Vermont in a new, net-zero capable house with solar panels and a mini-split system for heating and cooling. Every time I look at my mini split heads I am grateful for their quiet efficiency and that I’m no longer burning oil to heat my home. They aren’t beautiful, but I don’t think they’re ugly either, just there. Decorate as if they don’t exist and I think you’ll cease to see them after a while. And really, who cares what anyone else thinks?
  • Jake The Wonderdog
    5 years ago

    Austin Air Companie I can see what you do for a living... You have made this point about Mini-splits before... I'm asking if you have any real data to back it up.

    I'm aware of how maintenance on mechanical systems works. I was responsible for the maintenance on a couple of 12 story buildings and a 7 story mid-rise.

    But again, this sounds a lot like resistance to change rather than anything else.

    Laurie Tillett - do you mind sharing what system you have (had). When I've used them I have never had that issue.

  • Carolyn T
    5 years ago

    We just finished building our home and had the same choice to make. I couldn't get over the look of the mini splits so we went with the traditional system We did opt for the heavy duty spray/foam insulation to keep our home as energy efficient as possible so hopefully we won't have to run the systems as much.

  • Jake The Wonderdog
    5 years ago

    So for the OP:


    The big advantages I see are the efficiency and the ability to operate zones independently.


    These units use variable speed compressors, DC brushless motors on the blowers, and have very high SEER ratings.


    A single outdoor condensing unit can support eight (in the case of LG) indoor zones that can operate individually. So you don't have to cool rooms you aren't using (like when you want the bedroom cool at night but not the rest of the house).


    They also solve a problem with "the upstairs is too hot" or "the room with the S facing windows gets hotter than the rooms on the N side" etc.


    The big disadvantage I see is that the indoor unit can be ugly unless you use the vented units like you are considering.

  • roarah
    5 years ago

    I feel I must point out that my ducted half of my minisplit system does have a lower seer than my ductless unit. The ducted seer was still better than the high velocity systems I also explored but more in tune with standard ducted units.