A door assembly for an air conditioner indoor unit includes a door mounting plate, a door, a guiding part, and a drive assembly. The door mounting plate includes a receiving groove and a guiding groove. The door is configured to be movable in a direction approaching and away from the door mounting plate. The guiding part is connected with the door, located at a side of the door facing the door mounting plate, and movably disposed in the guiding groove. The drive assembly is configured to drive the door to move, and is disposed in the receiving groove.

A ventilation unit is for ventilating an indoor space, and incorporates an air cleaning device and mechanical restrictor for controlling a restriction to a flow resulting from a pressure differential across the unit. There is determination of the inside and outside air pressures in the vicinity of the unit and of air quality parameters inside and outside. The air cleaning device and the mechanical restrictor are controlled in dependence on the determined air pressures and air quality parameters. This provides a fan-less, and hence low-power ventilation unit, which relies on throttling the natural air flow across the unit to provide flow control, and hence enable control of air quality. The air cleaning device may be operated only when the flow is into the inside space, saving power.

A ventilation unit is for ventilating an indoor space, and incorporates an air cleaning device and mechanical restrictor for controlling a restriction to a flow resulting from a pressure differential across the unit. There is determination of the inside and outside air pressures in the vicinity of the unit and of air quality parameters inside and outside. The air cleaning device and the mechanical restrictor are controlled in dependence on the determined air pressures and air quality parameters. This provides a fan-less, and hence low-power ventilation unit, which relies on throttling the natural air flow across the unit to provide flow control, and hence enable control of air quality. The air cleaning device may be operated only when the flow is into the inside space, saving power.

An air duct device and an air handling apparatus are provided. The air duct device can include a housing, a first air duct, and a second air duct. The first air duct is arranged in the housing and has an air input end and an air output end. The second air duct is arranged in the housing and has an air input end and an air output end. The air input end of the second air duct passes by the air output end of the first air duct.

An air duct device and an air handling apparatus are provided. The air duct device can include a housing, a first air duct, and a second air duct. The first air duct is arranged in the housing and has an air input end and an air output end. The second air duct is arranged in the housing and has an air input end and an air output end. The air input end of the second air duct passes by the air output end of the first air duct.

The disclosed technology includes devices and systems for an economizer of a heating ventilation and air conditioning (HVAC) system. The disclosed technology can include an economizer for an HVAC system comprising a housing, an air inlet extending through a wall of the housing, a sliding door configured to transition between a closed position and an open position, and a controller configured to cause the sliding door to transition between the closed position and the open position based on temperature data. The sliding door can comprise a first portion forming a barrier and a second portion comprising at least one aperture. In the closed position, the first portion can align with the air inlet and substantially prevent ambient air from moving through the air inlet. In the open position, the second portion can align with the air inlet and permit the ambient air to move through the air inlet.

A ceiling type air conditioner including an indoor unit having a built-in heat exchanger and a built-in blower, and having a plurality of blowing passages for discharging, to the outside, air having passed through the heat exchanger; a discharge panel having a plurality of inlets into which air discharged through the plurality of blowing passages is delivered, an inner space at least partially communicating with the partiality of inlets, and a ring-or arc-shaped opening for discharging, into a room, air flowing into the inner space; and an air guide module mounted to the discharge panel, and moved upward and downward or rotated so as to vary airflow discharged through the opening.

A ceiling type air conditioner including an indoor unit having a built-in heat exchanger and a built-in blower, and having a plurality of blowing passages for discharging, to the outside, air having passed through the heat exchanger; a discharge panel having a plurality of inlets into which air discharged through the plurality of blowing passages is delivered, an inner space at least partially communicating with the partiality of inlets, and a ring-or arc-shaped opening for discharging, into a room, air flowing into the inner space; and an air guide module mounted to the discharge panel, and moved upward and downward or rotated so as to vary airflow discharged through the opening.

An air tight sealing cuff for a blast gate includes a pair of flat plates disposed on opposite sides of the slide mounting of the gate, and replaceable spring clips for holding the plates in position. Resilient gasket material applied to the plates forms a substantially air-tight seal between the slider and slide mount of the cuff and the exterior of the cuff. As a consequence, there is eliminated inadvertent leakage from the area around the gate slider, which would otherwise represent wasted energy. Improved efficiency and reduced carbon footprint result.

An air tight sealing cuff for a blast gate includes a pair of flat plates disposed on opposite sides of the slide mounting of the gate, and replaceable spring clips for holding the plates in position. Resilient gasket material applied to the plates forms a substantially air-tight seal between the slider and slide mount of the cuff and the exterior of the cuff. As a consequence, there is eliminated inadvertent leakage from the area around the gate slider, which would otherwise represent wasted energy. Improved efficiency and reduced carbon footprint result.