A system and method are described for conserving energy in HVAC systems. During certain temperature requests, ambient air can be supplied to a conditioned space and the HVAC compressor can be turned off to conserve power. During certain temperature requests, supply air can be adjusted through cycling of heating or cooling elements to conserve power and maintain desired space temperature. In various embodiments, supply air temperature, coil temperature, cabinet temperature and other values can be monitored for their effect on cooling and/or heating, and taken into account for determining how to best cool or heat a conditioned space.

The disclosure relates to a heat transfer assembly for a rotary regenerative heat exchanger. The assembly includes a rotor arranged between at least two separated fluid flow passages passing flow axially through the rotor, where each flow passage is connected to a sector part of the rotor. The assembly further includes a plurality of channels in the rotor for flowing a fluid through the rotor, each of the channels is enclosed by heat transfer and heat accumulating surfaces in the rotor, and the heat transfer and heat accumulating surfaces of the channels are made in a material providing an average axial thermal conductivity less than 100 W/mK arranged to reduce the Longitudinal Heat Conductivity of the rotor.

An air-conditioning management apparatus includes: a storage unit that stores a schedule including a set time and a set temperature; a communication processing unit that communicates with the air-conditioning apparatus and receives operation status information including a heat medium temperature; and a controller that performs a schedule control to control the air-conditioning apparatus according to the schedule. The schedule control includes an optimal start-up control to control the air-conditioning apparatus such that an indoor space reaches the set temperature at the set time, by starting an operation of the air-conditioning apparatus before the set time. The controller performs a preheating control or a precooling control to control the heat source unit such that before the optimal start-up control is started, the heat medium temperature included in the operation status information obtained from the air-conditioning apparatus falls within a target range including a previously set target heat medium temperature.

A heating, ventilation, and/or air conditioning (HVAC) system includes an enclosure that is divided by a partition extending between a first panel and a second panel of the enclosure such that the partition defines an outdoor air flow path and a return air flow path through the enclosure. The partition includes an opening extending between the outdoor airflow path and the return airflow path. The HVAC system also includes an energy recovery wheel that translatably extends through the opening and is positioned within the outdoor air flow path and the return air flow path. The energy recovery wheel is disposed within the enclosure at an oblique angle relative to the outdoor air flow path and the return air flow path.

An air handling system is disclosed that includes an integral chilled water refrigeration system. The air handling system additionally includes a first coil section that provides cooling and a second coil section that provides heating. The second coil section and associated terminal units are in fluid communication with the first refrigeration system.

An air handling system is disclosed that includes an integral chilled water refrigeration system. The air handling system additionally includes a first coil section that provides cooling and a second coil section that provides heating. The second coil section and associated terminal units are in fluid communication with the first refrigeration system.

A heating, ventilation, and/or air conditioning (HVAC) unit includes an energy recovery wheel, a first exhaust fan configured to draw a first air flow across the energy recovery wheel and discharge the first air flow from the HVAC unit, a second exhaust fan configured to draw a second air flow across the energy recovery wheel and discharge the second air flow from the HVAC unit, and a controller configured to operate the first exhaust fan and the second exhaust fan in an economizer mode and configured to operate the first exhaust fan and suspend operation of the second exhaust fan in an energy recovery mode.

A system and method are described for conserving energy in HVAC systems. During certain temperature requests, ambient air can be supplied to a conditioned space and the HVAC compressor can be turned off to conserve power. During certain temperature requests, supply air can be adjusted through cycling of heating or cooling elements to conserve power and maintain desired space temperature. In various embodiments, supply air temperature, coil temperature, cabinet temperature and other values can be monitored for their effect on cooling and/or heating, and taken into account for determining how to best cool or heat a conditioned space.

Systems and methods for controlling conditions in an enclosed space can include an integral make-up air system that can be arranged in the interior of the housing for an air conditioning system that uses scavenger air in an air-to-air heat exchanger (AAHX) to condition process air from an enclosed space. The make-up air system can take replenishment air from outside the air conditioning system and deliver it into the process air stream. The make-up air system can include at least one heating or cooling device to condition the replenishment air before the replenishment air mixes with the process air. In an example, the make-up air system can include a DX coil to selectively cool and dehumidify the replenishment air. The make-up air system can include a humidifier arranged in the flow path of process air between the process air inlet and the AAHX to selectively add humidity to the process air.

An example system is configured to control conditions in an enclosed space. The system includes scavenger and process plenums, a liquid-to-air membrane energy exchanger (LAMEE), a first liquid-to-air heat exchanger (LAHX), a second LAHX, and a fluid circuit The scavenger plenum is configured to direct scavenger air from a scavenger inlet to a scavenger outlet. The process plenum is sealed from the scavenger plenum and is configured to direct process air from a process inlet to a process outlet The process inlet receives heated air from the space and the process outlet supplies cooled air to the space. The LAMEE is arranged inside the scavenger plenum. The LAMEE is configured to use the scavenger air to evaporatively cool a first fluid flowing through the LAMEE. The temperature of the first fluid at a LAMEE outlet is lower than the temperature of the first fluid at a LAMEE inlet. The first LAHX is arranged inside the process plenum. The first LAHX is configured to directly and sensibly cool the heated air from the space to a supply air temperature using a second fluid flowing through the first LAHX. The second LAHX is arranged inside the scavenger plenum downstream of the LAMEE. The second LAHX is configured to receive and cool the second fluid heated by the first LAHX using the scavenger air. The fluid circuit transports the first and second fluids among the LAMEE, the first LAHX, and the second LAHX.