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Ductless · Fundamentals · Learn

What is a ductless mini-split, exactly?

A ductless mini-split is a small heat pump split into two parts: an outdoor unit and one or more indoor heads connected by refrigerant lines through a three-inch wall opening. Each head heats and cools the room it lives in — no ductwork required, which is why they're the go-to answer for additions, garages, ADUs, and older South Sound homes that never had ducts.

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Quick answer

  • One outdoor unit + one indoor head = single-zone. One outdoor unit + several heads = multi-zone.
  • Every head is its own thermostat — real room-by-room control.
  • They heat AND cool, efficiently, with inverter compressors.
  • Indoor options go beyond wall mounts: slim ducts, ceiling cassettes, and floor consoles.
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The parts, in plain terms

The outdoor unit holds the compressor. Each indoor head holds a coil and a quiet fan. A conduit with refrigerant lines, power, and a condensate drain links them. Installation needs a small exterior wall penetration and a place to mount both units — most single-zone installs are done in a day.

Zoning is the superpower

Central systems condition the whole house to one thermostat. Mini-splits condition each zone independently: the bonus room over the garage that's always cold, the south-facing bedroom that bakes in July, the shop you only heat on weekends. You stop paying to condition rooms you're not using.

Indoor unit styles

Wall-mounted heads are the familiar look, but ductless families also include slim-duct units that hide above a ceiling and serve a couple of rooms through short duct runs, recessed ceiling cassettes, and low floor-mounted consoles that fit where knee walls and windows crowd the space.

Where they fit best in the South Sound

Additions and ADUs (avoid extending old ductwork), homes with electric baseboard or wall heaters (huge comfort upgrade), garages and shops, sunrooms, and as whole-home systems for smaller houses. For larger homes with good ducts, a ducted heat pump or a hybrid layout is often the better fit — we'll tell you which.

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Family owned · WA Lic. INFINHA841B8 · 400+ Google reviews

Common questions

Are mini-splits noisy?

Indoor heads are among the quietest HVAC equipment made — typically low-20s to 40s dB depending on fan speed, quieter than most refrigerators. Outdoor units are also far quieter than traditional AC condensers.

Do they really heat in winter?

Yes. Modern ductless systems are inverter heat pumps; cold-climate models keep heating at temperatures far below a normal Washington winter — some rated to −22°F.

How many zones can one outdoor unit run?

Multi-zone outdoor units commonly support two to five or more indoor heads, depending on capacity. Zone count and head placement should come from a load calculation, not guesswork.

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Ductless mini-split services

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Infinity Heating & Air — licensed WA HVAC contractor (Lic. INFINHA841B8), family-owned in Graham. Last updated July 2026.

Choose Infinity & enjoy endless comfort.

Your perfect home environment awaits — call (253) 740-5135 or schedule service online and our team will take it from there.

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Bring us any repair or replacement quote and our licensed family team will verify it — free, honest, no pressure. If their price and diagnosis are right, we'll tell you.

Family owned · WA Lic. INFINHA841B8 · 400+ Google reviews