Provided is an air conditioning system that maintains a room pressure in a clean room at high accuracy while having a simple configuration. An air conditioning system includes: a fan filter unit including a supply air fan to supply air to a preparation room from a chamber including space above a ceiling of the preparation room; a fan filter unit including a supply air fan to supply the air to the preparation room from the chamber; and a fan filter unit including a return air fan to return the air from the preparation room through the chamber and to exhaust the air from the preparation room, and further includes: a pressure sensor provided in the preparation room; and a control unit to control a return air fan based on a value detected by the pressure sensor.

A heating, ventilating, and/or air conditioning (HVAC) system includes a variable speed pump configured to direct a chilled fluid through a free cooling circuit of the HVAC system. The free cooling circuit is configured to place the chilled fluid in a heat exchange relationship with ambient air. The HVAC system also includes a heat exchanger configured to place the chilled fluid in a heat exchange relationship with a conditioning fluid and a controller configured to operate the variable speed pump based on a parameter of the HVAC system.

An air handling unit of an HVAC system of a building including ducting through which airflow is controllably pushed by a supply fan of the HVAC system, at least one of a heating or cooling device within the ducting, an air handling unit controller configured to control operation of the at least one of the heating or cooling device within the ducting to generate condensation from air flowing through the air handling unit, and a collector tray placed within and/or integrated with the ducting below the at least one of the heating or cooling device and structured to collect the condensation, via gravity, for use in analysis of the condensation, wherein the at least one of the heating or cooling device, the air handling unit controller, and the collector tray are configured to collect the condensation including infectious disease particles from the air flowing through the air handling unit.

Provided is an air conditioning system that maintains a room pressure in a clean room at high accuracy while having a simple configuration. An air conditioning system includes: a fan filter unit including a supply air fan to supply air to a preparation room from a chamber including space above a ceiling of the preparation room; a fan filter unit including a supply air fan to supply the air to the preparation room from the chamber; and a fan filter unit including a return air fan to return the air from the preparation room through the chamber and to exhaust the air from the preparation room, and further includes: a pressure sensor provided in the preparation room; and a control unit to control a return air fan based on a value detected by the pressure sensor.

Methods for providing heating or cooling to a plurality of zones in a conditioned space, include adjusting a temperature of a primary airflow using a heating, ventilation, air conditioning, and refrigeration (HVACR) system including a heat pump circuit and distributing the primary airflow to a plurality of terminals in the zones. The methods further include directing heat from the heat pump circuit to at least one of the plurality of terminals and heating air at the at least one of the plurality of terminals using the heat directed from the heat pump circuit. The methods can further include utilizing sources and sinks of the heat pump circuit to efficiently provide the heating or cooling. Systems include the heat pump circuit, terminals, heat distribution, and can include a controller to operate those components.

A method for performing extremum-seeking control of a plant includes determining multiple values of a correlation coefficient that relates a control input provided as an input to the plant to a performance variable that characterizes a performance of the plant in response to the control input. The performance variable includes a noise-free portion and an amount of noise. The method includes determining an adjusted correlation coefficient by scaling a first value of the correlation coefficient selected from the multiple values relative to a second value of the correlation coefficient selected from the multiple values. The adjusted correlation coefficient relates the noise-free portion of the performance variable to the control input. The method includes using the adjusted correlation coefficient to modulate the control input provided as an input to the plant.

A chilled beam includes a body having a first side and a second side opposite to the first side. The chilled beam also includes a first mounting bracket coupled to the first side and configured to rotate against a first bias of the first mounting bracket in response to a first force against the first mounting bracket. The chilled beam also includes a second mounting bracket coupled to the second side and configured to rotate against a second bias of the second mounting bracket in response to a second force against the second mounting bracket.

When a humidity condition, including a humidity detected by a temperature and humidity sensor and a humidification load sensing unit falling below a threshold value, is met, an outside air conditioner supplies the heated and humidified air into the room. When the humidity condition is met during the indoor heating operation, the indoor heating operation is stopped or weakened. When the humidity condition is met, only the outside air conditioner is subjected to a heating and humidifying operation. Since the indoor air is not heated by the inside air conditioner more than necessary, when a heating load is low and a humidification load is present, a “conflicting state” can be prevented in which the inside air conditioner is subjected to a cooling and dehumidifying operation and the outside air conditioner is subjected to the heating and humidifying operation.

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 ionic liquid desiccant system utilizes an ionic liquid desiccant to draw moisture from a working fluid, such as air that flow into an enclosure, such as a home. The desiccant may be mixed with the working fluid or a separator that allows moisture transport therethrough may be configured between the ionic liquid desiccant and the working fluid. The ionic liquid desiccant system may be part of an air conditioning system and may remove the moisture from air that is cooled by flowing over an evaporator or heat exchanger coupled with the evaporator. The ionic liquid desiccant may be pumped from a desiccant chamber to a regenerator chamber to remove absorbed moisture. A dual-purpose chamber may act as a desiccant chamber and as a regenerator chamber. A refrigeration system may have an electrochemical compressor and may utilize metal hydride heat exchangers.