“There is no ductwork and I do not want the ceilings torn open.”
The problem both solve
Plenty of homes heat with a boiler and radiators and have no ducts at all. Others have ducts that reach part of the house. In both cases conventional ductwork means opening ceilings and losing closet space, and sometimes there is genuinely nowhere to run it.
Mini-splits: no ducts at all
A ductless mini-split pairs an outdoor unit with one or more indoor heads mounted in the rooms themselves. Refrigerant lines run between them through a small penetration, so no duct is needed.
Each head is its own zone with its own control, which suits a converted attic, an addition, a sunroom, or one room that has never been right. It also means visible indoor units, which some people mind and some do not.
High-velocity: small ducts, hidden
A high-velocity system such as Unico uses flexible tubing roughly two inches across instead of conventional rectangular duct. Air is delivered faster through much smaller outlets, which can be tucked into ceilings, floors and existing cavities.
The outlets are small and unobtrusive, and the mixing action of high-velocity delivery tends to even out temperatures within a room. The distinction worth understanding: this is still a ducted system — just with very small ducts — so it needs a path for that tubing, even if a far less intrusive one.
Choosing between them
- Whole-house coverage with minimal visible equipment leans high-velocity
- One room or a small group of rooms, independently controlled, leans mini-split
- Preserving plaster ceilings and period detail favours whichever needs fewer openings in your specific house
- Existing central heating you intend to keep changes which one integrates more cleanly
- Either way it is a survey question: what routes actually exist in this building