The maintenance aspects of what you are going to do will probably have you regret the decision in as few as a few years time.

Beyond that when the units start breaking, you'll wish you had chosen the ducted system with a single piece of equipment.

The more equipment you have, the more expensive it will be to keep them running.

Another advantage to a ducted system is to be able to cool / heat every individual room.

This is what makes mini splits impractical for many homes in the USA. A mini split is more or less a 'spot cooling / heating' appliance.

Ducts only get dirty if your house is dirty and you don't change your filters frequently. Add to that, six minisplits will cost you an arm and a leg - not at all cost effective for your application. I'd go traditional forced air with a 2 stage heat pump. On low (90% of the time), your wife will never hear the air movement and on those rare occasions when it kicks on high, if the ductwork is done properly, you still won't hear it.

Do you have a basement so condensate can run down? I have no experience with pumps to push it up, but that should work. If possible, I'd install the drains through a closet or something by placing them near the closets. That way you can get to them in case there is a clog or leak.

You might consider covering several areas with the small, flat AHUs that connect to short ducts. I do have some advice for how to combine indoor and outdoor parts. Smaller systems are convenient in the case of a power outage because you can run parts of it with a smaller backup genset. In addition to that, group indoor units that will be running at times with low demand, low output, together. That way the outdoor unit driving them can modulate better rather than toggling on and off.

i don't know why refrigerant lines in the attic would be a problem, but keep them as short as practical.

The mini-splits I've seen are single units. That would be a mess. However, I'm seeing multi zone mini-splits that could work well. Not the way I would do it... but could work well. Evidently you can do it with a distribution box so you have a single line-set to the condenser also. Do it with 2 multi-zone units with 8 zones.

Mini splits are also great for the manufactures, because when it comes time to replace it, that's a lot of equipment. Manufacturer's love that. In my climate that could be as soon as 10-12 years. Maybe 15 if you have maintenance performed meticulously, but with that much equipment -- you're going to spend some cash doing that as well. It's only money.

Austin Air Companie

Did you see the LG units I linked to? I was very impressed!

I don't have experience with installing or maintenance, but they look great on paper.

Up to 8 zones on a single outdoor unit. Each zone can be controlled completely independently.

Can run multiple lines back to the outdoor unit or use a distribution point. It's a 22 SEER unit and $4k for a 36k BTU - 4 zone system.

They sure solve a lot of problems.: First they solve the problem of zoning (upstairs / downstairs / large glass area / etc) . Related to that they solve the problem of not heating / cooling unneeded rooms. They also solve the problem of bad ductwork design. The high SEER is impressive also.

I'm very impressed by the technical data coming out of the app as well.

"I don't have experience with installing or maintenance, but they look great on paper."

If this is the basis of your recommendation, I'd keep it to yourself!

Thanks sktn77a , but no.

When you talked about 6 minisplits costing an arm and a leg, you clearly hadn't done your homework. You assumed they would all be separate systems also.

Great on paper often means stretching the truth, no mater how you slice it ---a mini split is still spot cooling, each room will need a cooling / heating head.

That winds up being a lot of equipment, not only to maintain and repair when it breaks... but also to one day replace.

You're talking to an AC mechanic who actually works on equipment. There is no such system that lives up to the 'paper' test. They all break. The more equipment you have, the longer you operate it and run it the more likely your chances... until ultimately one day the cost becomes so much to bear to keep fixing it you throw in the towel and relent on the notion of how well something 'looked' on paper.

Of course you could also find something else to waste your money on. So do what you want.