The present disclosure relates to a chiller. A compressor driver includes: a compressor including a compressor motor and a magnetic bearing; a coil driver including a switching element and to apply a current to a bearing coil of the magnetic bearing by a switching operation of the switching element to cause a rotor of the compressor motor to be levitated from or land on the magnetic bearing; and a controller to control the switching element of the coil driver, wherein, when the rotor of the compressor motor lands, the controller is configured to gradually decrease the current flowing through the bearing coil. Accordingly, damage to the rotor of the compressor motor can be prevented when the compressor motor is stopped in a magnetic levitation system.

A heat pump system includes a main heat pump system, a heat retaining layer and a reflecting layer coated on an partial inner surface of a building, a directly expanded strong cool-heat radiation plate having a distance from the reflecting layer, a heat radiating layer located at a side of the directly expanded strong cool-heat radiation plate and having a distance from the directly expanded strong cool-heat radiation plate, a buffer plate disposed between the heat radiating layer and the directly expanded strong cool-heat radiation plate, an anti-condensation trough disposed below the directly expanded strong cool-heat radiation plate. A sealed cavity is enclosed by the heat radiating layer and a wall surface, and the wall surface is formed by a combination of the partial inner surface of the building, the heat retaining layer and the reflecting layer, and, the sealed cavity is filled with air.

Individual zone temperature control sensors in a multiple zone system are monitored by a controller, and when one zone calls, the calling zone is allocated all of the airflow from the HVAC system except for a predetermined minimum that is allocated to the other zones. If all zones have equal priority, then the airflow continues to be supplied to the first calling zone until a temperature condition is satisfied, at which time the full airflow is allocated to a second calling zone and only the predetermined minimum is supplied to the first and all other calling zones. When two or more zones having different priorities, or set point deviations, are calling at the same time, the zone with the highest priority or whose temperature is furthest from a set point will become the single zone that is open and receives all of the air except for the predetermined minimum. Air continues to be supplied to that zone until it has achieved a desired temperature, until a higher priority zone calls, or until another zone is furthest from the set point. In order to provide maximum airflow to single zones according to the method of the invention, duct and outlet sizes must be larger than is necessary for conventional systems in which more than the minimum airflow is simultaneously allocated to multiple zones. Instead of utilizing conventional duct size calculations that assume simultaneous allocation of airflow to multiple zones, the design sizes the ducts in each zone to carry 100% of the system's airflow less the predetermined minimum.

Individual zone temperature control sensors in a multiple zone system are monitored by a controller, and when one zone calls, the calling zone is allocated all of the airflow from the HVAC system except for a predetermined minimum that is allocated to the other zones. If all zones have equal priority, then the airflow continues to be supplied to the first calling zone until a temperature condition is satisfied, at which time the full airflow is allocated to a second calling zone and only the predetermined minimum is supplied to the first and all other calling zones. When two or more zones having different priorities, or set point deviations, are calling at the same time, the zone with the highest priority or whose temperature is furthest from a set point will become the single zone that is open and receives all of the air except for the predetermined minimum. Air continues to be supplied to that zone until it has achieved a desired temperature, until a higher priority zone calls, or until another zone is furthest from the set point. In order to provide maximum airflow to single zones according to the method of the invention, duct and outlet sizes must be larger than is necessary for conventional systems in which more than the minimum airflow is simultaneously allocated to multiple zones. Instead of utilizing conventional duct size calculations that assume simultaneous allocation of airflow to multiple zones, the design sizes the ducts in each zone to carry 100% of the system's airflow less the predetermined minimum.

A method and system for providing a specific temperature to a specific bed in a common room having a plurality of beds is disclosed that include: an air filtering module for cleaning the air in the common room, a primary air conditioning module for setting a common temperature, a plurality of secondary air conditioning modules for setting a specific temperature at each bed, a plurality of air circulating modules for creating a convection current of the specific temperature from underneath each bed, and a central processing unit (CPU) for setting specific temperatures of each bed in accordance with a mode selected from an auto mode, a manual mode, and a timing control mode.

A method and system for providing a specific temperature to a specific bed in a common room having a plurality of beds is disclosed that include: an air filtering module for cleaning the air in the common room, a primary air conditioning module for setting a common temperature, a plurality of secondary air conditioning modules for setting a specific temperature at each bed, a plurality of air circulating modules for creating a convection current of the specific temperature from underneath each bed, and a central processing unit (CPU) for setting specific temperatures of each bed in accordance with a mode selected from an auto mode, a manual mode, and a timing control mode.

The dual-cycle and dual-outlet air conditioner includes two separate condensation-evaporation cycles that operate independently with respect to one another, but are contained within the same housing. Each cycle includes its own evaporator and condenser, but with a common return air intake/evaporator blower and a common condenser/exhaust fan. Two separate streams of cooled air are produced by the two separate evaporators, which may then be transferred through two separate ducts to supply cooled air to different zones within a building. The two separate condensation-evaporation cycles may be independently controlled by separate thermostats in the different zones of the building.

An air conditioning and heat pump tower includes a main casing, a plurality of connecting pipes, a compressor, a front heat exchanger, a rear heat exchanger, a fan unit, and an energy efficient arrangement. The energy efficient arrangement includes a first pre-heating heat exchanger supported in a front compartment of the main casing, and positioned between an outdoor air intake opening and an outdoor heat exchanging portion of the front heat exchanger. The air conditioning and heat pump tower may be operated between an air conditioning mode for absorbing heat from the indoor space, and a heat pump mode for producing heat to the indoor space. A predetermined amount of ambient air may be drawn through the outdoor air intake opening and may be pre-heated by the energy efficient arrangement before delivering to the indoor space.

An HVAC system for a building includes a heat exchanger configured to transfer heat from a chilled fluid circuit to a cooling tower circuit to provide cooling for a chilled fluid in the chilled fluid circuit, a cooling tower configured to remove heat from the cooling tower circuit to provide cooling for a coolant in the cooling tower circuit, one or more pumps configured to circulate the coolant between the cooling tower and the heat exchanger via the cooling tower circuit, and a free cooling controller. The controller is configured to determine an optimal flowrate of the coolant in the cooling tower circuit, determine an optimal flowrate of air through the cooling tower, and operate the one or more pumps and the cooling tower to achieve the optimal flowrate of the coolant in the cooling tower circuit and the optimal flowrate of the air through the cooling tower.

Provided is a transmission device for transmitting and receiving data through a transmission channel. The transmission device includes a transmission circuit unit configured to transmit data to the transmission channel. When an overcurrent caused by a simultaneous transmission of data to the transmission channel is detected during data transmission, the transmission circuit unit increases an output resistance, which is a resistance value for an output to the transmission channel, to an resistance value corresponding to a characteristic of a facility equipment item that transmits data to the transmission channel at the same time as itself.