A fresh air dehumidification device of a PTAC includes a cross-flow fan, a main evaporator, an air supply channel communicated with the cross-flow fan via the main evaporator, and an air exhausting device formed in the air supply channel for supplying air to the main evaporator. The air inlet of the air supply channel is connected to outdoor and the air outlet of the air supply channel is formed on a first air intake of the main evaporator. Fresh air passing through the air supply channel and the air exhausting device and is dehumidified by the main evaporator and then flows into the indoor so that the main evaporator of a PTAC is used as a dehumidifier in the dehumidification process, but without needing to increase a separate dehumidification system. So, the structure of the present disclosure can reduce the manufacturing cost of the PTAC.

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 HVAC system includes an air handling unit (AHU), a heat recovery device, and a controller. The controller is configured to determine an average heating or cooling demand of one or more zones served by the AHU, determine if a heating or cooling capacity is available at the heat recovery device, where the capacity available at the heat recovery device is a heating or cooling capacity to heat or cool the air from an outdoor environment with air extracted from the one or more zones served by the AHU, determine a heat recovery command setpoint based on the determined average heating or cooling demand and the determined available heating or cooling capacity, and send a signal indicative of the determined heat recovery command setpoint to at least one of the AHU and the heat recovery device.

A heat exchange ventilator includes: a partition wall that has a bypass opening allowing an exhaust air duct upstream of a total heat exchanger to communicate with the exhaust air duct between the total heat exchanger and a humidifier, and separates the exhaust air duct upstream of the total heat exchanger and a supply air duct downstream of the total heat exchanger; a bypass damper that opens and closes the bypass opening; and a controller that performs control to open the bypass opening by the bypass damper at a first time, and close the bypass opening by the bypass damper at a second time.

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.

An energy recovery ventilator includes first and second blowers, a pressure transducer and a controller. The first blower is configured to direct a first air stream into a first zone of an enclosure. A second blower configured to direct a second air stream into a second zone of the enclosure. A pressure transducer is configured to determine internal air pressure within the enclosure. A controller is configured to control the first blower and/or the second blower in response to the internal air pressure. A method includes fabricating a rooftop unit and an ERV housing, the rooftop unit comprising an economizer, the ERV housing comprising first and second blowers and a pressure transducer. The method further includes coupling the ERV housing to the economizer and coupling a controller to the pressure transducer, the controller configured to control the first and/or second blowers in response to the internal air pressure.

A smart ventilation system which performs the ventilation of indoors, increases the air quality in closed spaces and maintains air quality, which is positioned over a window and includes: a ventilation module on a main body, which is attached to the window so as to control the air passage between indoors and outdoors; indoor and outdoor sensor groups which measure the air values indoors and outdoors, respectively; and an electronic card which analyzes the sensor values and engages one or more of an air intake fan group, an air outlet fan group, a dehumidifier, and a humidifier as a result of the analysis. A device provides the necessary energy from the adaptor and water reservoir.

An apparatus is provided and arranged with an air control system to alternately direct a first and a second airflow to a first and a second energy-absorbing body in order to achieve a heat and moisture transfer between the two airflows. The energy exchange bodies alternate between recovery and release modes such that when one energy exchange body is in the release mode the other is in the recovery mode. Each of the first and second energy absorbing bodies is divided into a first latent energy recovery portion which includes a moisture absorbent material so that it is arranged to absorb latent energy and a second sensible energy recovery portion which is substantially free from moisture absorbent material so as to absorb primarily sensible energy. The second portion is arranged to supply heat to freezing air entering the energy absorbing body to prevent condensation and frosting damage to the first portion.

A ventilation unit for decentralised room ventilation systems, in which unit at least one reversible fan and a heat reservoir element are supplemented by an electrostatic precipitator for air purification. In addition, a filter assembly is provided for a ventilation system, in particular for a decentralised room ventilation system, having an air duct with an electrostatic precipitator through which an air stream to be purified is forced, with the precipitator extending over a predetermined section of the air duct. The filter assembly has, in the predetermined electrostatic-precipitator section of the air duct, at least one heat reservoir element impinged by the air stream, the electrostatic precipitator and the heat reservoir element thus being spatially restricted relative to one another.

A system for purifying and pre-conditioning intake air in an air conditioning unit comprises an energy exchange unit having an air inlet, an air outlet, a primary air flow running from the air inlet to the air outlet, and an active energy exchanging element or elements, and at least one spray washer having at least one nozzle, the spray washer positioned between the air inlet and the next active element, wherein the at least one spray washer is configured to dispense droplets of a fluid into the intake air from the at least one nozzle. A method for purifying and pre-conditioning intake air in an air conditioning unit is also described.