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Cassette Mini-split versus wall mount

Canyon21 | Posted in Energy Efficiency and Durability on

We are considering a cassette mini split in the upstairs bedroom with duct work leading to the other bedroom.  Is this OK to do in the attic space? We live in Denver, CO, so we have extreme temperatures in the winter and summer.  HVAC companies said that they would run all the lines in the attic as well.  Trying to reduce costs by only having one mini-split. Is this logical or even reasonable?   Sq footage of one bedroom is  about 21′ X 13′.  Other room is 11′ X 13′.   We plan on putting a lot of extra insulation in the attic after the installation.  Looking for advice on this idea.

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  1. C L | | #1

    Any reason you are not considering a ducted mini-split?
    Usually the heads, and cassettes are designed to deliver to only one room. They have units designed to be ducted; the advantage of the ducted mini's over other air handlers is that they are very small.

    You should try and not run duct with conditioned air in it through unconditioned spaces. So if your attic is unconditioned, you may wish to seek another solution.
    - Create a small space in your attic that is conditioned - ie build a box around the air handler and the duct, with no insulation between the box and conditioned space, but plenty of insulation between the box and the unconditioned attic.
    - Alternatively, is your layout such that you might be able to put the ducted mini in a closet near the ceiling and serve both bedrooms? This works well when the bedrooms are next to each other with offset closets in between. The ducted minis are only about 12" deep so they don't take up too much space in the closet near the ceiling. Some people put the ducted mini's in a closet ceiling, then drop a soffit down the hallway for ductwork to serve all the bedrooms.

  2. Canyon21 | | #2

    Thanks for your comments. Unfortunately the layout is not conducive for sharing through a closet. Space is tight as the house is really only 1 and 1/2 stories tall

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