It’s a ‘mini split’ in US lingo. There are thin, highly insulated refrigerant lines going between the outside unit and the inside unit. The inside unit exchanges heat with the air. https://www.daikin.com.au/our-product-range/split-system-air...

That thing's an eyesore compared to a duct to me.

Much like solar panels on the roof (which I have also heard Americans describe as an eyesore), once they are common enough your eyes just slide over them and you don’t notice.

I don’t see rooftop solar panels unless I go outside and intentionally look for them.

A mini-split system puts an ugly, cheap, plastic wall-cyst within your field of view in every room they’re installed.

Why are they plastic wall-cystst though? Wouldn't a manufacturer offering a less obtrusive look (I'm not thinking of fancy boutique, just Ikea grade surfaces) alongside a standard interface for third party options get a huge market advantage?

> your eyes just slide over them and you don’t notice.

Nah.

There have been minisplits in the US for years, they are just not very common. Moreover they have been commonplace in Asia for decades now. They are noticeable. I personally think they look like ass. They are huge and you are blind if you don't notice them. There is a reason why ducted or recessed models are available internationally for luxury homes. It has nothing to do with Americans.

They're noisy too. Not loud, it's a quiet hum, but it's annoying if that annoys you, some people are sensitive to noise. The system I have doesn't seem to have a variable-output control, so it uses an on/off hysteresis that drives me up the wall. I could deal with a constant hum, but the stop start every minute or two is annoying. A previous house I lived in the ducts were absolutely silent unless it was on high you could hear some airflow noise. They can be placed anywhere wall floor ceiling (depending on construction of course), and have a wide range of styles.

Ducts are a superior look and experience IMO, just slightly less efficient. Nothing wrong with preferring them.

They’re not even less efficient if installed correctly, it just takes some thought and some insulation. And you get really good filtering with very low likelihood of mold in the bargain.

Though mini split heads can be ducted too. There are several choices, wall heads, ceiling heads, ducted heads etc. The wall head is just the cheapest solution since it’s very easy to install.

Just to add to what the other commentator said, ducted based systems are VERY hard to balance. It is possible using something called an Volume Damper, but it is uncommon (and adjusting them can be challenging, sometimes requiring removal of drywall).

So people COMMONLY wind up with unbalanced floors, and people typically try to fix it by adjusting the vent register opening with mixed success.

Part of the problem is that the thermostat is biased to wherever it is located. You can get systems with remote add-on temperature sensors, but that doesn't by itself adjust where heat/cold is being sent through a ducted system.

The great thing about a Mini-Split is that you're, at minimum, heating each floor independently with its own thermostat. You can then put in e.g. interior door vents that simply let air pass between common areas and the rooms when the doors are closed.

This can go even further with for example two Air Handlers per floor (quad units) on the east and west. So that as the sun moves, the correct level of adjustment can be applied to only the side of the floor that needs it.

I moved from a ducted heating house to a multi head split system house about 18 months ago.

One of the biggest pros (in addition to the improved efficiency of a heat pump) is I heat and cool less space than i did before because i can target individual rooms. When i'm in my office all day I only need to heat my office. When it's hot and I'm struggling to sleep only cool my bedroom. There's no point in heating my living room^^ at 08:30 in the morning if i don't intend to spend time in there till 17:00.

Sure, when it gets to 17:00 my living area might not be comfortable, but that can easily be overcome by turning it on half an hour or so beforehand (either manually or with a timer).

^^ I don't live somewhere where freezing pipes are a concern. But i'd imagine you could just set them differently, slightly above freezing for the rooms you aren't in and a comfortable living temperature in the room you're in.

How would it behave in a place like Chicago where we've had recent weather events that take the temperature from 40F to -10F in a couple of days? Will the system catch up that fast without ducts?

Faster since you just target the rooms you occupy.