Glossary · Heating, cooling & ventilation
Ductless mini-split
Also called: mini-split · mini-splits · ductless heat pump · ductless mini-split heat pump · ductless split · wall-mounted heat pump
An air-source heat pump with wall- or ceiling-mounted indoor heads connected by refrigerant lines, needing no ductwork.
What it means
One outdoor unit can serve one indoor head (single-zone) or several (multi-zone). Each head heats and cools its own area, which makes zoning easy and avoids duct losses, but rooms without a head, such as closed-off bedrooms, may not get enough heat. They suit homes without ducts, such as those heated by baseboards or boilers.
Why it matters in an audit
Mini-splits let homes without ducts switch to heat pump heating and cooling, but heads must be placed and sized to match each area's heat loss.
Typical numbers
Reference values with their sources. Your auditor’s report gives the figure for your own house.
| What | Value | Source |
|---|---|---|
| ENERGY STAR Cold Climate, ductless | HSPF2 ≥ 8.5 | energystar.gov ↗ |
| NEEP v4.0, ductless | HSPF2 above 8.5 | neep.org ↗ |