Mini splits for an ADU or tiny home

Why it's the obvious choice

Accessory dwelling units, tiny homes, casitas, and backyard offices are small, often built without room (or budget) for ducts and a furnace. A single ductless mini split fits perfectly:

• One unit does everything. A single wall head heats and cools the whole space - no separate furnace, no AC, no ducts.
• No ductwork. Ideal for a compact or newly built structure where ducts would waste space and money.
• Efficient and quiet. Low running costs and a near-silent indoor head - it matters more in a small space where you're always near the unit.
• Often 115V. Many small units run on a standard 115V circuit, simplifying the electrical for a small build - see best 115V mini splits.

Sizing a small space

ADUs and tiny homes are small, so you're usually in the smallest capacity range (often 9,000-12,000 BTU), but don't just grab the smallest unit - a tiny home with lots of glass, an open loft, or poor insulation can need more than the floor area suggests. Start from the size chart and the sizing guide, and remember that oversizing a small space is easy to do and causes short-cycling and poor humidity control - right-size it.

Year-round use? Go cold-climate

If someone lives in the ADU or you use the tiny home through winter, choose a cold-climate model so it heats reliably when it's cold - a small, well-insulated space plus an efficient heat pump is a comfortable, cheap-to-run combination. For a three-season studio you mainly cool, a standard unit is fine.

Practical notes

• Electrical. Even a 115V unit needs a proper dedicated circuit - plan it into the build (electrical requirements).
• DIY option. For an owner-built tiny home, a DIY mini split can be self-installed (the electrical still needs to be to code).
• Placement. In a compact space, mount the head where it won't blow directly on a bed or desk - see where to put a mini split.

The bottom line

For an ADU or tiny home, one right-sized single-zone mini split is the whole HVAC answer - ductless, efficient, heating and cooling in one, often on a simple 115V circuit, and a cold-climate model if you'll use it in winter. Size it carefully (small spaces are easy to oversize) and you're done. Shortlist a unit in the product finder.

FAQ

What size mini split do I need for an ADU or tiny home? Usually one of the smaller units (often 9,000-12,000 BTU), sized to the square footage - but account for glass, lofts, and insulation, and avoid oversizing a small space, which causes short-cycling.

Can one mini split heat and cool a whole tiny home? Yes - a single single-zone unit handles a small open space completely, heating and cooling with no ductwork. Choose a cold-climate model if you'll use it in winter.

Can a mini split for an ADU run on a normal outlet/circuit? Many smaller units are 115V and run on a standard dedicated circuit, which simplifies a small build. Larger units are 230V; check the specific unit.

Are mini splits good for ADUs? They're the go-to choice - ductless, one unit for heating and cooling, efficient, quiet, and often 115V, which fits the compact, no-ductwork nature of an ADU or tiny home.