Ceiling Cassette AC

Overview

A ceiling cassette AC is a split air conditioner whose indoor half is recessed flush into a suspended ceiling, leaving only a square grille visible. It cools larger open spaces, offices, shops, conference rooms, more evenly than a wall unit because it blows in all four directions from the center of the room. Like any split system it pairs a quiet indoor section with a noisy Outdoor Condensing Unit mounted outside, the two joined by a refrigerant line set.

The Indoor Cassette Unit hides its sheet-metal body above the ceiling tiles; its Decorative Face Panel sits flush with the grid. A center turbofan draws room air up through the filter and the Evaporator Coil, then throws the chilled air out the four edge slots past the Swing Louver Assembly. Because the unit is up in the ceiling, a Condensate Drain Pump is needed to lift condensate to a drain line. Everything is coordinated by the Control Module board and a wall-mounted controller.

How it works

The refrigeration cycle is split between the two units. In the outdoor unit, the Scroll Compressor, an inverter scroll that varies its speed to match the load, pressurizes refrigerant and pushes it through the Condenser Coil, where the outdoor fan rejects the heat. The high-pressure liquid travels indoors through the Refrigerant Line Set, passes the electronic expansion valve, and boils in the Evaporator Coil, chilling the air the Turbofan Blower pushes across it. The R32 Refrigerant Charge loops continuously between the two coils.

Two details set the cassette apart from a wall split. First, the turbofan and four-way Swing Louver Assembly spread air to the room's corners, with each louver driven by its own motor so airflow direction can be set per side. Second, because the coil sits above the ceiling with no gravity drain available, the Condensate Drain Pump collects condensate in a sump and lifts it up to a drain pipe, a float switch shutting the system down if the water rises too high. The indoor Control Module board runs the blower, louvers, and pump while exchanging temperature and demand signals with the inverter board outdoors over the communication cable in the line set.