What Is an Indoor Head (Wall Cassette)?

An indoor head is the wall-, ceiling- or floor-mounted unit of a ductless system containing a coil, blower and filters. It delivers conditioned air straight into the room and is controlled as its own zone, with wall-mounted being the most common residential form.

Also called: indoor head · wall cassette · air handler head · indoor unit · evaporator head

Why it matters to you

Each head is a zone, so comfort depends on choosing locations that actually serve the way rooms are used rather than simply where the line set is easiest to run. Height and throw also affect how well a head dehumidifies the space it serves.

What to do about it

Head filters are washable and are homeowner maintenance — rinse them regularly, more often in a coastal or sandy environment. The coil and drain pan behind the filters are service items, and are where mould and blockages develop if neglected.