Hi everyone,

First, I appreciate all and any help you may provide. We initially had a huge issue with a Unico install and have been fighting with the installers (lets just say that with the system running full power, the upstairs would reach 80+ degrees and ultimately leaked into our ceiling and an electrical box), finally who agreed to remove the system and refund us the entire amount. This system was less than 2 years old.

We are looking at installing a new a/c system as a replacement. I have had a couple of quotes about the recessed mini-splits/cassettes. One company quoted using 1-way from Mitsubishi; the other omni-direction/4-way from Bryant. Each recommended 5 units, 2 for the main level and one for each bedroom. We are choosing this style as I hate the look of the wall units (plus we have a lot of stuff on the walls), and we have a boiler for baseboard heating.

From a house design, it is a split level. It faces south. There is attic access for the main level that connects to the the upper level with the bedrooms so we can get away with a single outside unit and running the pipes internally. We would have 2 cassettes for the main level - this houses the kitchen/dining room and the family room, each rectangular with one side being 25 x 12.8 feet, the other side 25 x 15 feet. The upstairs have 3 bedrooms, a central hallway (maybe 12 x 4 feet), a guest bath in the hallway, and a master bath off of the master bedroom.

The first quote has the 1-way above windows, which actually flows with the rooms, particularly the main level. Each of these on the main level have a window on the East side of the house. The west side of this level has the stairs to go up to the bedrooms or a small staircase down to the entry way. The 4-way have them in the center of the room. Both are similar in price sans the carpentry.

The hallway, master bath, and guest bath all get incredibly hot. There are no windows in the hallway or guest bath, and 2 windows in the master bath. The entire upstairs does but we have portable a/c units right now for the bedrooms.

That being said, aside from the downside of having to get a framer to create openings for the 4-ways, is there a benefit to one vs the other? We have 16" joist spaces. Would a better option be doing with Ducted splits so that the upstairs could then also vent to the hallway and bathrooms? or use one ducted for the master bedroom and bath? We do know that insulation is an issue, we have someone lined up to do that once the units have been installed, which will help some but seeing the issues with had from before, I want to make sure we are doing the right thing. Again, thanks for the input and I appreciate all opinions on the matter!