In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and an EEV coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine an occurrence of a first event, initiate a closure of the EEV, initiate operation of the compressor at a completion of the air conditioning cycle to pump down a refrigerant to the outdoor coil, and cease operation of the compressor when a low-pressure switch is tripped.

An air conditioning system includes: an air conditioner configured to supply air-conditioning air; and an air conditioner control device configured to control the air conditioner. The air conditioner includes: an outside air passage, through which outside air flows; a return air passage, through which return air flows; an outside air heat exchanger; a return air heat exchanger; an outside air vaporizing humidifier configured to humidity the outside air by utilizing evaporation of water; and a return air vaporizing humidifier configured to humidify the return air by utilizing evaporation of water. The air conditioner control device includes a first vaporizing cooler configured to operate at least one of the humidifiers to perform vaporization cooling of the air-conditioning air while preventing the air-conditioning air from exchanging heat with a heat exchange medium.

An HVAC system is described having components of a variable refrigerant flow (VRF) outdoor compressor unit connected to an indoor fan coil unit. The indoor fan coil unit supplies air to ducts that condition a plurality of zones. Each zone has a volume modulating air damper that can maintain a predetermined volume of air flowing through it. As the dampers for some zones vary between open and close positions, the air pressure in the ducts changes. The volume modulating dampers compensate for these pressure changes, ensuring that only the predetermine volume of air is passing into the zones. By regulating the volume of into each zone, the volume modulating air dampers can restrict the air volume through the fan coil causing the outdoor unit to reduce compressor speed, thereby saving energy.

An HVAC system is described having components of a variable refrigerant flow (VRF) outdoor compressor unit connected to an indoor fan coil unit. The indoor fan coil unit supplies air to ducts that condition a plurality of zones. Each zone has a volume modulating air damper that can maintain a predetermined volume of air flowing through it. As the dampers for some zones vary between open and close positions, the air pressure in the ducts changes. The volume modulating dampers compensate for these pressure changes, ensuring that only the predetermine volume of air is passing into the zones. By regulating the volume of into each zone, the volume modulating air dampers can restrict the air volume through the fan coil causing the outdoor unit to reduce compressor speed, thereby saving energy.

A heating unit for a heating, ventilation and/or air conditioning (HVAC) system may have a first airflow path through the heating unit, a second airflow path through the heating unit, and a heater assembly having a first heating coil positioned within the first airflow path, a second heating coil positioned within the second airflow path, and a coil divider separating the first heating coil and the second heating coil.

A heating, ventilation, and air conditioning (HVAC) system includes a vapor compression cycle comprising a microchannel heat exchanger. A fluid is configured to circulate within the vapor compression cycle in a first direction during a first mode and is configured to circulate within the vapor compression cycle in a second, opposite direction during a second mode. A receiver is integrally formed with the microchannel heat exchanger.

The present disclosure involves a free cooling temperature conditioning system having an air handling assembly having a first cooling coil. The first cooling coil includes an intake port receiving coolant at a first temperature and further includes an output port for the coolant at a second temperature. The air handing assembly receives return air flow from a space being temperature conditioned, where the return air flows over the first cooling coil to condition the return air to supply air. The air handing assembly delivers the supply air into the space being temperature conditioned. The conditioning system also includes a controller configured to maintain a temperature difference between the second temperature and the first temperature.

An air movement system for plant cultivation. In an embodiment, the system comprises an air conditioner configured to receive a gas mixture of air and carbon dioxide, regulate a temperature of the gas mixture, and output the gas mixture at the regulated temperature. In addition, the system may comprise a first bladeless fan configured to receive the gas mixture output by the air conditioner and supply the gas mixture as an air flow to a first crop area at a velocity towards an air intake, and at least one second bladeless fan configured to assist the air flow from the first crop area to a second crop area so as to maintain the velocity towards the air intake.

An air treatment device having a flexible air hose, duct or gooseneck member. The air hose, duct or gooseneck member permits an inlet end thereof to be positioned in proximity to a patient so that a negative pressure can be created around the patient so that air can sucked or vacuumed into the system whereupon it is treated as the air flows through the system.

A heating, ventilation, and/or air conditioning (HVAC) unit may include a supply fan section having a supply fan disposed therein to force a supply air flow through a discharge plenum of the HVAC unit. The HVAC unit may also include an economizer positioned adjacent the supply fan section to receive an outdoor air flow and direct the outdoor air flow into the supply fan section.