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Community and Q&A

One or two mini-splits for small rooms

MoiraK | Posted in General Questions on

Need help.   A small  room, 14′ by 25.5′, that had been added on to the garage side of the house, is being remodeled to provide a living space and sleeping space for me. Room is divided by a 9′ long wall, giving 14 by 14 to living space, a walkway/hall that will turn left into another room (previously a mudroom, now a walkway to main house and a powder room.

Sleeping area is pretty much just a 9′ by 11′ with space next to the hall for closet.

I don’t want a mini-split in the bedroom. I am sensitive to noise and cold (arthritis and Fibromyalgia). Using baseboard radiators for heat. Contractor is calling for 2 inside and 2 outside units for a/c – 9000 and 12000 BTU. That sounds like freezing me. I will not be able to handle all that noise nor cold air. Plus the owner’s a/c is on the back wall of what will be the bedroom.  So wondering if I put the one unit on the garage side of the room that is kiddy corner across from the bedroom, would that work. Imagine would have to run pipes in the ceiling and down; would that effect draining? I would not use a/c if I didn’t have Asthma and laminate flooring. I also have medical conditions that make me feel cold most of the time.  Thank you.

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  1. Trevor_Lambert | | #1

    Two minisplits is almost certainly too much for the area you describe, but it would help to know the climate and construction details. It's possible one unit will both heat and cool the whole area. If you've never experienced a minisplit, you will be surprised how quiet it can be. Usually i can't even tell if mine is on based on sound from 15 feet away.

    What is the connection between a/c, asthma and laminate flooring? Are you confusing a/c with ventilation? Because a/c isn't going to do anything to help with fresh air delivery or VOC removal.

  2. MoiraK | | #2

    Location is Niles, Michigan. Room is on concrete slab. Once drywall up and painted, grandsons will put down moisture barrier, 1/4" cork insulation sheets and then laminate floating floors. Previous owner (this is my daughter's home) called this his crafts room. No ducts. He heated it with a large garage heater, which has been removed. The ceiling and walls are well insulated. Good use another window in sleeping area but that entails siding so not going there. Relationship: Asthma - hard to breathe if air is to hot and humid. Laminate floors can buckle from to much heat and humidity. Doctor finds it necessary to remind me that heat is harder on older people.

  3. walta100 | | #3

    One mini will handle the large room. Insist on a manual J calculation to size the unit.

    If the mini will be used mostly for heating ask for the floor mounted unit.


  4. walta100 | | #4

    Please note most code officials would not approve a bed room/ sleeping area without 2 exits one generally being a window. Understand your plan puts your life at risk. If you need a permit do not call it a bed room.


  5. Expert Member
    Dana Dorsett | | #5

    With insulation in the walls and ceiling a code-min double panes the heating load of that 14' x 26' room is likely to be less than 7500 BTU/hr @ 0F (roughly your 99% outside design temp) , and barring a large west-facing window the cooling loads would be even smaller. Any cold climate 3/4 tonner would cover it, and could even be overkill.

    A PAIR of mini-splits would be EXTREME overkill. Find a different contractor, or run your own Manual-J cooling/heating load calculations.

    A 3/4 ton ducted mini-split with a good turn-down ratio mounted just below the ceiling in the closet with short flex ducts to both the sleeping area and other space might be just the ticket. At the lowest blower speeds (where it will be running 90% of the time) they are literally quieter than a whisper, and it won't be something to bonk your head on when walking by like the wall-coils.

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