Concealed duct minisplit questions
Is there any reason I couldn’t install a concealed duct type unit, at least temporarily, without any ducts? I saw a diagram of a suggested installation, and it looked basically like they just enclosed the thing in a bulkhead; maybe there was a “duct”, but it couldn’t have been more than 6 inches long. Reason for asking is that I am 90% sure I will end up needing ducted a/c into my bedrooms, but I’m pressed for time getting the ducts installed and would like to get the minisplit installed, and hey if it does a reasonable job of cooling the whole upstairs with just open doors, maybe I’ll leave it without ducts.
Second question: The cooling load is below 9kBTU, but the 9k model has been in “pre order” status for months, while the 12k model is on sale for the same price as the 9k and ready to ship. The 12k model has a slightly lower SEER/EER (22.5/12.5 vs 25/14.5). Would you wait for the 9k or just order the 12k?
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As long as it blows the air where you need it, and you use a filter on the intake side, it's fine.
What brand? They might actaully have the same coil and turn-down. How far below 9k is your actual load?
Senville, which I think is a Midea. I don't remember the exact load number, maybe something like 6k? The whole house is below 12k. This is for the second floor, which is much less than half the square footage of the total, and quite a bit lower glazing than downstairs. I know with hot air rising, this one could take more than the calculated load share, but I figure if I set this one at a slightly higher temperature than the downstairs one that effect will be modest.
you have to pull air to push air. So, you're going to be sucking air from somewhere. I'd just stick a ceiling cassette in (Mitsubishi system). It bring air in through the middle of the head and either cools or heats it and blows it back out into the room. No ducts, no wall mount system.
You definitely can. It will work just as well as a wall mount.
Lot of ducted units have the option to rotate the intake to the bottom of the unit (some need a sheet metal piece for this), which makes it easier as you won't have to do any return ducting.
You would not even need to build the bulkhead, won't be pretty but it will work.
The supply ducts you can do later, and close it all up. Here is a hallway mount supplying 2 bed 1 bath and living space.