Mini-splits these days are available as multi-head (I think that’s the term) units, where a single outside unit can supply 2,4, or 6 units individually and independently.
They’re remarkable, and I would go for a mini-split system over a central unit 100 times out of 100.
> where a single outside unit can supply 2,4, or 6 units individually and independently
In my current home, I have two "heads" attached to a single outside unit, but they cannot operate independently beyond setting different fan speeds or closing the vent really. If one of the mini-splits is set to heat and the other switches to cooling, they will booth start cooling, or vice versa, the head units just blindly blow air over what ever is being pumped through the line and the last unit to send a command to switch mode "wins".
Maybe there are clever heat pumps that truly allow fully independent control of the head unit when connected to multiple heads, but given the flow of refrigerant has to reverse direction completely when switching between heating and cooling, I don't see how they can operate fully independently when they are sharing the same refrigerant lines.
There is only one reversing valve inside the outside unit for all the head units connected to one outside unit in my experience, but would love to see examples of systems that do permit this if they exist.
An extra clever system would include every temperature controlled appliance in the house. Heat could be exchanged between the hvac, water heater, refrigerator, and oven.
When the oven is done cooking it can dump heat into the water heater (and or furnace in the winter). The fridge and HVAC could dump heat into the water heater before pumping it outside in the summer.
By “independently” I meant that one room could be heating/cooling while other rooms aren’t doing anything at all. Or one room could be warmer/cooler than another.
As opposed to central unit’s all-or-nothing approach.
It's units in 6 different rooms (3 bed, office, living, dining) so 6 sets of units.
After reading some other comments I realize one vital detail is that they were installed in a renovated house that already had suitable holes to the outside and power outlets where the units were going, so the install job was just mounting the units, pulling the tubing and gassing it, no cutting things up or doing electrical work.
The price would at least double if we needed all the holes cut open, and I have no idea what the electrical work would cost.
It’s very normal here in Portugal. If you looked carefully and weren’t picky about the brands, you could have 6 mini-splits installed for $3000 all-in.
I would expect that installing six is maybe twice as expensive as installing one. All the overhead of scheduling the technician, traveling to the location, getting the tools out, etc stay the same. Installing six is vastly more efficient and that should be reflected in the price
regardless, this is incredibly cheap