A building panel may be installed below a slab in the construction of buildings. The building panel supports the slab and also provides a ventilation layer that may be depressurized to eliminate or reduce infiltration of radon gas into the building. The ventilation layer may comprise channels which provide a two-dimensionally interconnected void. Ventilation panels which include collars for connecting to ventilation systems may be provided. The panels may be installed directly on compacted soil. The building panels may additionally provide sub-slab insulation and/or a capillary break for water drainage. In some embodiments the building panels are formed substantially entirely of thermal insulating material such as rigid polystyrene foam. In an example embodiment the panels are approximately 4 inches thick and have a grid of intersecting channels formed on an underside of the panels.

The present invention comprises: a first filter, and a second filter positioned in the slipstream of the first filter in the airflow direction; a dust amount sensor positioned before the first filter in the airflow direction, having a hole part through which dust passes, and transmitting, per unit of time, each of a first total, which is the amount of dust in a first size range, and a second total, which is the amount of dust in a second size range smaller than the first size range, of the dust passing through the hole part; and a control unit for outputting the service signal of the first filter if the accumulated value of the first total transmitted from the dust amount sensor exceeds a first set value, and outputting the service signal of the second filter if the accumulated value of the second total transmitted from the dust amount sensor exceeds a second set value, wherein the optimum service time of each of the first filter and the second filter, which are capable of filtering dust of different sizes, can be independently calculated such that the unnecessary service of one of the first filter and the second filter can be blocked, and the optimum service time according to the indoor quality can be indicated.

A multi-type air conditioner may include three pipes, including a high-pressure pipe, a low-pressure pipe, and a liquid line which may be connected to a plurality of indoor units, in which some of the indoor units may be operated in a cooling mode and the rest of the indoor units may be operated in a heating mode, such that waste heat from the indoor units operated in the heating mode may be recovered to be used for the indoor units operated in the cooling mode.

A multi-type air conditioner may include three pipes, including a high-pressure pipe, a low-pressure pipe, and a liquid line which may be connected to a plurality of indoor units, in which some of the indoor units may be operated in a cooling mode and the rest of the indoor units may be operated in a heating mode, such that waste heat from the indoor units operated in the heating mode may be recovered to be used for the indoor units operated in the cooling mode.

A data center cooling system includes an evaporative cooling system. The evaporative cooling system includes fans configured to circulate outside air at ambient conditions through an entry zone of a data center, and atomizers positioned upstream of the entry zone configured to spray atomized water into the circulating outside air. The atomized water evaporates in an evaporation zone and cools the outside air to produce cooled air, which is directed through racks of computers positioned downstream of the evaporation zone.

A data center cooling system includes an evaporative cooling system. The evaporative cooling system includes fans configured to circulate outside air at ambient conditions through an entry zone of a data center, and atomizers positioned upstream of the entry zone configured to spray atomized water into the circulating outside air. The atomized water evaporates in an evaporation zone and cools the outside air to produce cooled air, which is directed through racks of computers positioned downstream of the evaporation zone.

An air inducing device for an air conditioner and an air supply control method to resolve user discomfort. The device includes an inducing member and an air storage member communicating with an air supply port, and the inducing member has an air inlet and an air outlet; an air inducing panel is provided at the air inlet, and the air inducing panel has a plurality of air inducing holes; an air outlet panel is provided at the air outlet, and the air outlet panel has a plurality of air outlet holes; an air speed increasing structure is provided between the air storage member and the inducing member, and the air speed increasing structure forms a negative pressure in the inducing member to allow indoor air to enter f and mix with air discharged before entering the room, so that the temperature of blown air is closer to room temperature.

An air inducing device for an air conditioner and an air supply control method to resolve user discomfort. The device includes an inducing member and an air storage member communicating with an air supply port, and the inducing member has an air inlet and an air outlet; an air inducing panel is provided at the air inlet, and the air inducing panel has a plurality of air inducing holes; an air outlet panel is provided at the air outlet, and the air outlet panel has a plurality of air outlet holes; an air speed increasing structure is provided between the air storage member and the inducing member, and the air speed increasing structure forms a negative pressure in the inducing member to allow indoor air to enter f and mix with air discharged before entering the room, so that the temperature of blown air is closer to room temperature.

A system for ventilation, dehumidification, and cooling according to an exemplary embodiment in the present disclosure may include an outdoor unit dehumidifying and cooling introduced outside air; and an indoor unit connected to the outdoor unit to perform ventilation, in which the outdoor unit includes a dehumidification rotor, an evaporative cooler, an evaporative condenser, a ventilation damper, a heating unit, and a control module operating and stopping at least one of the dehumidification rotor, the evaporative cooler, the evaporative condenser, the ventilation damper, or the heating unit.

A ventilation air conditioning structure including a room that has a floor portion to a fourth wall portion, a first wall portion to be a building outer wall in which an air supply opening is formed in a vicinity of a third wall portion, and an air exhaust opening that is formed in a vicinity of the fourth wall portion. The ventilation air conditioning structure also includes an air conditioner that is disposed inside the room and where at least one of air sending openings of a room interior unit is capable of sending air in a direction of a second wall portion, and an external-air conditioner that is disposed outside the room. The external-air conditioner includes heat exchangers that are incorporated in a refrigerant circuit of the air conditioner via a branched pipe that is branched from a refrigerant piping and a casing that houses the heat exchangers.