An access control system receives a trigger command for controlling a ventilation system; determines that the trigger command includes a lock trigger to hold an entrance door in a closed position; and induces a locking differential air pressure between opposite sides of the entrance door in response to the lock trigger, where the locking differential air pressure is sufficient to bias the entrance door to contact or to increase contact with a door frame in the closed position. The access control system may also determine that the trigger command includes an open assist trigger to ease an opening of the entrance door; and may induce an opening differential air pressure between the opposite sides of the entrance door in response to the open assist trigger, where the opening differential air pressure is sufficient to bias the entrance door to reduce contact with the door frame in the closed position.

Methods and systems for controlling ventilation in a building based on measurements of air pressure differences between inside and outside of the building envelope in order to prevent infiltration of pollutants in general. The system is particularly suited to prevent infiltration of radon from the ground. Air pressure is measured on both sides of the building envelope and the building's ventilation system is controlled in order to ensure that the air pressure inside the envelope is at least a minimum threshold higher than the air pressure on the outside of the building envelope.

A system for mitigating airborne pathogens from a livestock house is disclosed. In an embodiment, there is disclosed a cross-flow ventilation system, which is fluidly connected to a livestock house and configured to control the air quality and movement by introducing ambient air into at least one air filtration system that is attached to a side wall of the house; conditioning the air in the air filtration system by performing at least one step selected from filtering, cooling, disinfecting, or pressurizing the air; introducing the conditioned air into an air chamber; flowing the conditioned air from the air chamber into the house through at least one ventilation panel to the opposing sidewall with a laminar or substantially laminal flow of air; and removing the air from the house using an exhaust fan attached to a side wall opposite the side wall containing the air filtration system.

An access control system receives a trigger command for controlling a ventilation system; determines that the trigger command includes a lock trigger to hold an entrance door in a closed position; and induces a locking differential air pressure between opposite sides of the entrance door in response to the lock trigger, where the locking differential air pressure is sufficient to bias the entrance door to contact or to increase contact with a door frame in the closed position. The access control system may also determine that the trigger command includes an open assist trigger to ease an opening of the entrance door; and may induce an opening differential air pressure between the opposite sides of the entrance door in response to the open assist trigger, where the opening differential air pressure is sufficient to bias the entrance door to reduce contact with the door frame in the closed position.

An encapsulated cleanroom system comprising a processing chamber and a storage section in which the processing chamber is stored, wherein, during operation, the pressure in the storage section is lower or higher than the pressures in the processing chamber and exterior space. The system can simultaneously prevent the entry of outside gases into its processing chamber and the leakage of the gases inside the processing chamber to the exterior space.

An airflow control system of a work vehicle includes a controller having a memory and a processor. During an initialization phase, the controller is configured to instruct a blower to operate at an initialization capacity to provide an airflow from an external environment into an interior of a cab of the work vehicle. The controller is also configured to receive a first signal indicative of a pressure within the interior of the cab and to determine a restriction factor based at least in part on the first signal. In addition, during an operation phase, the controller is configured to receive a second signal indicative of the pressure within the interior of the cab and to determine an input flow rate of the airflow from the external environment into the interior of the cab based at least in part on the restriction factor and the second signal.

The present invention discloses a method for the air conditioning of closed environments (314), particularly for vertical farms, comprising the steps of: conditioning the air by means of an air treatment unit (301); distributing and taking the conditioned air into the closed environment (314) through a plurality of channels (303, 305, 306, 307, 308, 309) connected to said air treatment unit (301); generating a flow of conditioned air exiting, through a plurality of openings (316), from a first vertical wall (317) and taken in, through a plurality of openings (316), from the opposite vertical wall (315) of the closed environment (314); alternatively inverting the delivery direction of the conditioned air along a substantially parallel direction with respect to the floor of the closed environment (314) so as to hit the inside of the closed environment (314) alternatively from one direction and subsequently from the opposite direction of the two vertical walls (318a, 318b). The invention also discloses a system for implementing the described method.

An access control system receives a trigger command for controlling a ventilation system; determines that the trigger command includes a lock trigger to hold an entrance door in a closed position; and induces a locking differential air pressure between opposite sides of the entrance door in response to the lock trigger, where the locking differential air pressure is sufficient to bias the entrance door to contact or to increase contact with a door frame in the closed position. The access control system may also determine that the trigger command includes an open assist trigger to ease an opening of the entrance door; and may induce an opening differential air pressure between the opposite sides of the entrance door in response to the open assist trigger, where the opening differential air pressure is sufficient to bias the entrance door to reduce contact with the door frame in the closed position.

The present invention discloses a method for the air conditioning of closed environments (314), particularly for vertical farms, comprising the steps of:conditioning the air by means of an air treatment unit (301);distributing and taking the conditioned air into the closed environment (314) through a plurality of channels (303, 305, 306, 307, 308, 309) connected to said air treatment unit (301);generating a flow of conditioned air exiting, through a plurality of openings (316), from a first vertical wall (317) and taken in, through a plurality of openings (316), from the opposite vertical wall (315) of the closed environment (314);alternatively inverting the delivery direction of the conditioned air along a substantially parallel direction with respect to the floor of the closed environment (314) so as to hit the inside of the closed environment (314) alternatively from one direction and subsequently from the opposite direction of the two vertical walls (318a, 318b). The invention also discloses a system for implementing the described method.

A system includes a controller, a heating, ventilation, and air conditioning (HVAC) unit, first and second dampers, and first and second pressure sensors. The first damper is positioned at a first air duct that supplies air from an exterior of a premises. The second damper is positioned at a second air duct that supplies air from an interior of the premises. The first pressure sensor is configured to detect an air pressure exterior to the premises. The second pressure sensor is configured to detect an air pressure within the premises. The controller is configured to receive the detected exterior air pressure and the detected interior air pressure, and the controller is configured to change the air pressure within the premises by adjusting at least one of the first damper and the second damper based on the detected exterior and interior air pressures.