Abstract: Thermoelectric enhanced hybrid heat pump systems are provided herein. A compressor increases the pressure of refrigerant within tubing. A first heat exchanger is downstream of the compressor and changes enthalpy of first fluid flow through heat exchange with refrigerant. A second heat exchanger changes enthalpy of second fluid flow through heat exchange with refrigerant. A thermoelectric device is downstream of the first heat exchanger and reduces refrigerant temperature. Expansion valves are downstream of the thermoelectric device and first heat exchanger, respectively located on first and second sides of the thermoelectric device, and expand refrigerant and reduce refrigerant pressure while conserving refrigerant enthalpy. At least one valve reverses refrigerant flow within the tubing without changing compressor operation. A control system controls the thermoelectric device and at least one valve to switch the heat pump system from heating mode to cooling mode and from cooling mode to heating mode.

Abstract: A method is provided for controlling heating, ventilation and air conditioning (HVAC) equipment configured to control environmental conditions in confined areas of a facility. The method includes monitoring at least one of the HVAC equipment or the confined areas. The method includes detecting a failure of a first of the HVAC equipment to control an environmental condition in a first of the confined areas to a setpoint for the environmental condition, with the environmental condition including at least one of temperature, humidity or air quality. The method includes controlling at least one of the first or a second of the HVAC equipment to cause additional conditioned air to permeate to the first of the confined areas from an adjacent, second of the confined areas to move the environmental condition in the first of the confined areas closer to the setpoint to compensate for the failure, automatically as a direct result of detection of the failure.

Abstract: An example operation includes one or more of determining that an enclosed area at least partially encloses a transport; determining a variance between a first temperature within the enclosed area and a second temperature outside the enclosed area; and determining that a dangerous condition exists within the enclosed area, based on the variance.

Abstract: A method for providing personalized comfort to occupants of an environmentally conditioned space includes sensing a pre-adjustment pressure within a variable air volume diffuser, remotely adjusting a position an individually-adjustable directional outlet of the variable air volume diffuser, sensing a post-adjustment pressure within the variable air volume diffuser, and modifying the airflow through the variable air volume diffuser such that the post-adjustment pressure is equal to the pre-adjustment pressure. The variable air volume diffuser includes individually-adjustable directional outlets and a controller configured to regulate air pressure within the variable air volume diffuser when an individually adjustable directional outlet is adjusted. A user device in operative communication with the variable air volume diffuser includes a user interface to remotely adjust an adjustable directional outlet of the variable air volume diffuser to provide personalized comfort for the user.

Abstract: A temperature control system. The control system includes a flow sensor configured to monitor water flow through a valve, an actuator coupled to the valve, and a first controller configured to establish a setpoint for a second controller. The second controller monitors fluid flow through the valve and combines a weighted first command from the first controller and a weighted second command from the second controller to generate a control signal, wherein combining the weighted first command and the weighted second command is based on the reliability of the flow sensor. The second controller further controls the actuator based on the control signal.

Abstract: Systems, methods, and apparatus are provided for monitoring and improving air quality in single- and multi-zone indoor spaces. The system for monitoring and improving air quality includes a built structure that includes an indoor space with environmentally-controllable zones, an environmental control system, sensor arrays positioned within the environmentally-controllable zones, and a control circuit configured to monitor air and remediate air within the indoor space. Multiple zones in the indoor space may be bundled together in multiple remediation bundled-areas for remediation by separate air handling systems and/or processes. Additionally, multiple zones may be delineated within the indoor space for sensor installation processes.

Abstract: A system includes a concentration sensor, a flow sensor, and a controller. The concentration sensor is configured to measure a concentration of a contaminant in a cabin of an aircraft. The flow sensor is configured to measure a flow rate of air into the cabin. The controller is configured to determine whether a concentration measurement of the contaminant in the cabin exceeds a first concentration threshold. The controller is configured to, in response to determining that the concentration measurement does not exceed the first concentration threshold, control the flow rate of air into the cabin based on a flow rate setpoint. The controller is configured to, in response to determining that the concentration measurement exceeds the first concentration threshold, control the flow rate of air into the cabin based on a flow rate setpoint and a correction factor that is based on a flow sensor tolerance.

Abstract: An air-conditioning apparatus includes a fan configured to send air to an air-conditioned space, a fan motor configured to drive the fan, a duct having a plurality of air outlets, the air sent by the fan flowing through the duct, a detection unit configured to detect an air flow rate of the fan, a damper provided to each of the plurality of air outlets, and a fan motor control unit configured to control a rotation speed of the fan motor such that the air flow rate assumes a constant value relative to variations in an opening degree of the damper of a plurality of dampers.

Abstract: 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.

Abstract: An air conditioner interface is an interface to which an air conditioner, a manipulation terminal, and an external device are connected, the manipulation terminal being used by a user to manipulate the air conditioner, the external device having an air-conditioning function. The air conditioner interface includes a control unit that controls operation of the air conditioner and operation of the external device in accordance with an operating mode that is set to either a first operating mode to solely operate the air conditioner or a second operating mode to enable the air conditioner and the external device to operate simultaneously.

Abstract: A method for providing personalized comfort to occupants of an environmentally conditioned space includes sensing a pre-adjustment pressure within a variable air volume diffuser, remotely adjusting a position an individually-adjustable directional outlet of the variable air volume diffuser, sensing a post-adjustment pressure within the variable air volume diffuser, and modifying the airflow through the variable air volume diffuser such that the post-adjustment pressure is equal to the pre-adjustment pressure. The variable air volume diffuser includes individually-adjustable directional outlets and a controller configured to regulate air pressure within the variable air volume diffuser when an individually adjustable directional outlet is adjusted. A user device in operative communication with the variable air volume diffuser includes a user interface to remotely adjust an adjustable directional outlet of the variable air volume diffuser to provide personalized comfort for the user.

Abstract: Refrigerant leak detection systems as well as related climate control systems and methods are disclosed herein. In an embodiment, the refrigerant leak detection system includes a transmitter configured to emit an acoustic wave, and a receiver configured to detect the acoustic wave. The transmitter and the receiver are mounted within a space outside a conduit configured to carry a refrigerant of a climate control system. In addition, the refrigerant leak detection system includes a controller coupled to the transmitter and the receiver. The controller is configured to: determine a time of flight for the acoustic wave between the transmitter and the receiver, and determine whether a refrigerant is present in the space based on the time of flight.

Abstract: A premixed underground ventilated henhouse includes a gable, a sidewall, a roof and a floor. An inner chamber is further provided in the middle of the henhouse. A partition is hermetically provided between the sidewall and an inner wall. An air inlet plate is provided between the two inner walls. A plurality of fans and a plurality of air inlet windows are uniformly provided on an inner roof. A plurality of wet curtains and an air vent are provided on the sidewall. Air outlet slots are uniformly provided on the inner wall. An underground exhaust bunker is provided under the floor. A vent pipe and a fan are provided on one side of the underground exhaust bunker. An air outlet is provided at an upper end of the vent pipe.

Abstract: A system for controlling pressure of a sealed enclosure such as a glove box or containment vessel, including: a first control circuit configured to keep a current pressure value of the sealed enclosure within an operational pressure range, and configured to isolate the sealed enclosure and to transmit a primary alarm signal in event of current pressure value reaching one or other of primary limits of a degradation range; an independent secondary safety circuit separate from the primary circuit, the secondary safety circuit configured to isolate the sealed enclosure and to transmit a secondary alarm signal when the pressure of the sealed enclosure reaches one or other of secondary limits of an alarm range.

Abstract: Laboratory ventilation is integrated. The HVAC room controller requests changes in the exhaust set point of one or more fume hoods. By allowing the fume hoods to respond to such HVAC requests, the fume hood exhaust may be turned down to a point below the highest level that could be needed. The request may be used to turn the fume hood exhaust back up, so greater energy savings may be possible in non-peak demand operation of the HVAC system.

Abstract: An illustrative damper system includes a damper blade that is configured to be positioned within a duct, such as a bypass duct of an HVAC system. A shaft is in communication with the damper blade, a torsion spring is in communication with the shaft, and a force adjustment mechanism is in communication with the torsion spring. The shaft, the damper blade, and the torsion spring may be configured such that the shaft may affect movement of the damper blade about a rotation axis and the torsion spring may provide a bias force to the shaft for biasing the damper blade toward a desired position (e.g. closed position).

Abstract: The disclosure relates to an overpressure encapsulation system for explosion protection, comprising the following: a device (1), in particular a painting robot (1), an overpressure-encapsulated device housing (2) comprising a housing outlet (6) for discharging gas out of the device housing (2), a compressed air system (3, 4) for operating the device (1), said compressed air system (3, 4) being arranged within the device housing (2), a sensor assembly (7, 8, 9) for measuring at least one fluid variable (Q, PI, PA), and an analysis unit (11) which analyzes the fluid variable (Q, PI, PA) measured by the sensor assembly (7, 8, 9), in particular in order to detect a leakage of the device housing (2).

Abstract: A vent bypass system is created by forming a bypass hole through a vent cover door of two adjacent vent cover doors. A tube flange is extended from a bottom surface of the vent cover door, concentric with the bypass hole. A first vent cover door covers an entry vent and the second vent cover door covers an exit vent. One end of a flexible tube is secured to one of the two tube flanges and the other end of the flexible tube is secured to the other one of the two tube flanges. Air/gas blown into the room will bypass circulating through the room by going through the flexible tube from the entry vent to the exit vent. Any suitable means to connect the various vents can be used, such as, but not limited to any pipe, hose, tube, conduit, or the like.

Abstract: In some embodiments, an atmosphere conditioning device may include a housing which may form a cavity. An air inlet may be formed into the housing, and the air inlet may be in fluid communication with the cavity. A filter medium which may govern the entrance of atmosphere into the cavity may be coupled with the housing so that the filter medium may be in fluid communication with the cavity and the first air inlet. A first air outlet may be disposed on the first side of the housing, and the first air outlet may be in fluid communication with a first air motivator. The first air motivator may also be in fluid communication with the cavity and may motivate conditioned air, which has passed through the filter medium, from the cavity and out of the device through the first air outlet.

Abstract: HVAC module has an air inlet, an evaporator downstream of the blower and a heater downstream of the evaporator, and a rear mixing zone downstream of the evaporator and the heater, wherein a control valve prevents cold air from flowing back towards the hot air by regulating the pressure of the cold air. A method is devised to control anti-backflow control valve of such an HVAC module by the steps of reading pressure and temperatures at various points in the HVAC module; setting air flow and temperature discharge targets; calculating the resistance of the control valve and a bland valve; determining corresponding control valve and blend valve positions; and moving the control valve and blend valve to those corresponding positions.

Abstract: An air filter system and an air filter therefore are provided for use in a building with first and second zones separated by a wall-door system having a wall with a door therein. The gap between a lower edge of the door and the floor has an air flow permitting region. An air filter is mounted to extend substantially across the air flow permitting region. In a preferred embodiment the air filter extends across a lower edge of a door and filters air that passes below the lower door edge and a portion of the floor below the lower edge.

Abstract: A threat detection system includes a facility including at least three separate rooms located in the facility and a positive pressure zone located external to the facility. A ventilation system is coupled to the at least three separate rooms. A first room is located in the facility, wherein the first room includes a first room pressure zone that is negative with respect to the positive pressure zone external to the facility. A second room is located in the facility and connected to the first room, wherein the second room includes a second room pressure zone that is negative with respect to the first room pressure zone.

Abstract: A dual ventilation system is provided for a structure. The system has a suction tube assembly with an exhaust outlet in an upper end thereof and an exhaust fan therein. An intake vent or other intake means is in a lower portion of the structure in flow communication with the suction tube assembly. At least one channel is proximate a lower portion of the structure in flow communication with at least one lower interior portion of an exterior wall of the structure and in flow communication with the suction tube. In structures having a sump pump, the sump pump liner is in flow communication with the channel.

Abstract: A return fan control system for an HVAC system comprises a supply fan control loop, a return fan control loop and a building pressure control system. The supply fan control loop comprises a duct pressure controller arranged to control a supply fan to a duct pressure setpoint. The return plenum pressure control loop comprises a return plenum pressure controller arranged to automatically control a return fan to a return plenum pressure setpoint determined by a setpoint reset function. The building pressure control system is operable to control a building pressure. The building pressure control system may comprise a building pressure control loop and an outside air control loop cooperatively arranged to control an exhaust damper in response to an outside air intake.

Abstract: A method and apparatus for economically filtering air into swine farms and other animal enclosures are provided. Advantageously, the invention substantially reduces the risk to airborne transfer of disease into animal enclosures. In one embodiment, a method for providing clean air to an animal enclosure includes providing an animal enclosure having an animal containing volume for containing a plurality of animals, removing air from the internal volume via at least one exhaust fan, and filtering air being pulled into the enclosure by the at least one exhaust fan using a fully sealed filter, the fully sealed filter having a particle separation sufficiently efficient to prevent detection of live (PRRS-) virus downstream of the filter, using polymerase chain reaction (PCR) analysis of samples collected with a cyclonic aerosol collector.

Abstract: Systems and methods are disclosed for ventilating a building using a rooftop heating ventilating and air conditioning system that in one instance involve determining a first outdoor airflow into the system through a barometric relief damper; subtracting the first outdoor airflow from a minimum required outdoor airflow rate to arrive at second outdoor airflow; and setting an outdoor damper to provide an outdoor airflow through the outdoor damper that is greater than or substantially equal to the second outdoor airflow. Other systems and methods are disclosed.

Abstract: A passive ventilation stack for a room, building or the like comprises an interior space and first and second openings providing fluid communication between the interior space and a room to be ventilated, and the outside atmosphere. A control system is provided for varying the size of the openings, so as to cause natural heat exchange between relatively cool ventilation air entering the stack from outside and relatively warm air entering the stack from a room or building to be ventilated.

Abstract: A multi-pressure-quantity fan control system for a computer system is provided. The multi-pressure-quantity fan control system includes a controller. The controller provides a pressure-quantity control signal to a fan of the computer system, in order to set the fan to operate in one of a first pressure-quantity setting and a second pressure-quantity setting, wherein under a predetermined rotating speed, the fan has a first pressure-quantity curve for the first pressure-quantity setting and a second pressure-quantity curve for the second pressure-quantity setting.

Abstract: A vapor mitigation system includes at least one vacuum pipe constructed and arranged to collect vapors beneath the floor of a building and to vent the vapors and a blower coupled to the at least one vacuum pipe. The blower is constructed and arranged to create a vacuum under the floor of the building. The vapor mitigation system further includes a controller configured to dynamically control a level of power supplied to the blower. The controller adjusts the level of power supplied to the blower in response to one or more environmental measurements.

Abstract: Disclosed is a habitat assembly comprising a habitat structure for undertaking hot work. Air is supplied to the habitat by an air supply system, through a conduit. The air supply system comprises a fan or blower. Means for altering the temperature or humidity of the air supplied to habitat is positioned down stream of the fan or blower. The fan or blower both creates and maintain an overpressure within the habitat structure and pumps air through the means for altering the temperature or humidity. The means for altering temperature may comprise a heater and/or an air conditioning unit. Also disclosed in an air conditioning unit for a habitat assembly, adapted to facilitate emergency shut down.

Abstract: A fan system for a variable air volume heating and/or air conditioning unit comprising a fan array with a control system to eliminate surge at low operating flows and to maximize operating range. The fan control system includes a fan pressure sensor for determining the pressure rise across the fan array and a fan airflow sensor for determining the total airflow generated by the fan array. A surge controller is programmed to constantly monitor the calculated surge pressure as the fan speed control is modulating the fan speed in response to user demands. As airflow increases or decreases in response to changes in fan speed, so will the calculated surge pressure. The surge control turn fans on and off to ensure that the operating fans are running in their optimum fan speed ranges. Thus, the fans in the fan array are prevented from reaching the surge point.

Abstract: The current invention discloses a novel spray booth containing a plurality of spacers disposed on the walls or ceiling, and a plurality of fans attached to the spacers. A spacer allows a fan to be disposed at an angle and at a certain distance away from the wall or ceiling, allowing sufficient airflow for spraying or curing an object within the housing. Having fans emit airflow toward both the top and the sides of an object allows optimal coating and heating of the object. A ceiling fan may also be disposed within a plenum in the ceiling of the spray booth.

Abstract: An apparatus and method for adjusting air pressure of a room. The apparatus comprises an air receive duct (4) arranged to receive air from the room (2), an air distribution casing (5) connected to the receive duct (4), first and second air vents (6, 7) connected to the air distribution casing (5) and arranged to convey air coming from the receive duct (4) out of the apparatus (1), and a control means (8) arranged to adjust the flow resistance of the second air vent (7) in relation to that of the first air vent (6).

Abstract: A climate control apparatus for a cleanroom livestock building includes a supply air unit, comprising a supply air conveyor device, an exhaust air unit comprising an exhaust air conveyor device, a temperature sensor, an air pressure sensor, and a climate control unit. The climate control apparatus is adapted to reduce the volume of air conveyed by the exhaust air unit whenever the air pressure detected by the air pressure sensor falls below a predetermined lower air pressure limit value, increase the volume of air conveyed by the exhaust air unit whenever the air pressure detected by the air pressure sensor exceeds a predetermined upper air pressure limit value, and increase the volume of air conveyed with the supply air unit when the temperature detected by the temperature sensor exceeds a predetermined first upper temperature limit value.

Abstract: The door insert of the present invention balances air pressure in a closed environment. It includes a frame that defines a slot. A pair of tabs emanates from opposing sides of the frame to attach the frame to a door. Media, which has a plurality of apertures therethrough, resides in the slot. The frame, with media installed therein resides within a notch in an edge of a door. Air is permitted to flow through the door insert to balance the air pressure within an environment divided by the door. The frame is preferably ABS plastic and the media is preferably paper. The appearance of the frame and media may be modified to aesthetically match the decor of the door, door hardware and surrounding environment.

Abstract: There is described a method for controlling an exhaust system having at least two fans, a plenum chamber interconnecting the at least two fans, and a bypass air damper in the plenum chamber to allow bypass air to flow therethrough, the method comprising: monitoring pressure in the plenum chamber of the system; detecting a variation of the pressure beyond a predetermined range; and regulating operation of the exhaust system in response to the pressure variation in order to return the pressure to within the predetermined range.

Abstract: The present invention relates to a measure for minimizing an undesired passage of fluid from a first sector (1) to a second sector (2) separated by a non-fluid-tight separation (3), wherein a first pressure (P1-1) prevails in the first sector (1) and a lower second pressure (P2-1) than the first pressure (P1-1) prevails in the second sector (2). An intermediate chamber (4) which separates the two sectors (1, 2) from one another is arranged at the separation (3). A conveyor mechanism (5) is further provided which is designed to convey fluid from the intermediate chamber (4) to the first sector (1).

Abstract: A variable-air-volume system for modulating the speed of a supply fan by measuring a plurality of inlet static pressures within the inlet of a corresponding plurality of terminal boxes within the system; calculating a plurality of setpoint errors equal to the difference between the plurality of inlet static pressures and a corresponding plurality of terminal box setpoint pressures; selecting minimum setpoint error out of all of the calculated setpoint errors; and modulating the fan speed as a function of the minimum setpoint error. The system can also utilize a power adjustment factor to modify the terminal box set point pressures.

Abstract: Disclosed is a smoke control system provided in a high-rise building for separately supplying leakage air flow and supplementary air flow, including: a blowing means for supplying air into a building; a ventilating means having a leakage air flow supplying passage and a supplementary air flow supplying passage connected to the blowing means for introducing air; and an air supply damper connected to the leakage air flow supplying passage and the supplementary air flow supplying passage to supply air into each lobby of a building according to the leakage air flow and supplementary air flow.

Abstract: A return fan control system for an HVAC system comprises a supply fan control loop, a return fan control loop and a building pressure control system. The supply fan control loop comprises a duct pressure controller arranged to control a supply fan to a duct pressure setpoint. The return plenum pressure control loop comprises a return plenum pressure controller arranged to automatically control a return fan to a return plenum pressure setpoint determined by a setpoint reset function. The building pressure control system is operable to control a building pressure. The building pressure control system may comprise a building pressure control loop and an outside air control loop cooperatively arranged to control an exhaust damper in response to an outside air intake.

Abstract: A room pressure controlling system having a local exhaust valve, a supply air valve, a common exhaust air valve, controllers and a differential pressure sensor. The controller calculates a correction control output value for the valve operated as the room pressure controlling valve, which is either the supply air valve or the common exhaust air valve, based on a setting value and a room pressure measured by the differential pressure sensor. The controller evaluates whether or not the supply airflow rate and/or the exhaust airflow rate is changing, and if an airflow rate is changing, emphasizes rapid responsiveness of the room pressure control than a reduction in the frequency of actuation of the room pressure controlling valve, if the airflow rate is stable, the controller emphasizes the reduction in the frequency of actuation of the room pressure controlling valve than the rapid responsiveness of the room pressure control.

Abstract: Embodiments of the invention provide a system capable of reducing negative pressure. The system includes a make-up air system that can be configured and arranged to be installed within a structure, such as a building. The system can also include a pressure switch that is configured and arranged to sense a pressure within an exhaust duct coupled to an exhaust device. The pressure switch can also be configured to communicate an activation signal and a deactivation signal to the make-up air system. In some embodiments, communication of the activation and deactivation signals can be at least partially dependent on the pressure within the exhaust duct. Moreover, the pressure switch can be configured and arranged to be retroactively coupled to at least one of the exhaust duct and the exhaust device.

Abstract: An air filter system and an air filter therefor are provided for use in a building with first and second zones separated by a wall-door system having a wall with a door therein. Weatherstripping is mounted between side and upper edges of the door and a door frame in the wall and between the lower edge of the door and the threshold region of the floor to substantially seal against air flow between the door edges and the door frame and floor when the door is closed. An air flow permitting opening is provided in the wall-door system, sized to permit a controlled amount of airflow between the first and second zones when there is a pre-determined pressure differential between said zones. An air filter is mounted in such opening.

Abstract: An air-pressure-control system, the system comprising a system inlet, a system outlet, and a variable-speed fan configured to operate at a speed. A motor controller in communication with the fan is configured to control the speed of the fan. A differential-pressure transducer configured to monitor an air pressure at the system inlet and an air pressure at the system outlet. A closed-loop pressure controller in communication with the motor controller and differential-pressure transducer, wherein the pressure controller is configured to vary the speed of the fan based on the pressure differential between the inlet and outlet of the system, thereby controlling a pressure within a space. An ultraviolet kill chamber may be disposed between the inlet and outlet to expose airborne particulate to UV radiation. The system may also have a filter located within an air-flow path between the system inlet and system outlet.

Abstract: The present Invention relates to an overpressure-based system applied to protect vertical evacuation routes against smoke infiltration, that can be used in the objects such as hospitals or laboratories, where it is necessary to accurately maintain the pressure difference between two zones on a preset level, characterised in that the system's controlling & working unit 14 is connected with the upper fan's frequency converter 19 through the upper fan's controller 15, and, next, through the reversible upper fan 4, and this system's unit is also connected with the upper fan's frequency converter 20 through the lower fan's controller 16. and, next, with the reversible lower fan 5.

Abstract: An isolation damper for preventing the migration of air from a ventilated space includes a high differential pressure sealing chamber in the damper assembly that prevents the flow of air from the “clean” side of the damper assembly to the “dirty” side thereof. Pressurized air leaking out of the sealing chamber creates reverse flow leakage toward the dirty side which assures the clean side air is not contaminated by the dirty side air. Differential pressure between the sealing chamber and the dirty side is monitored with the differential pressure reported and alarmed externally if reductions in pressure indicate the sealing effect of the sealing chamber could be affected.

Abstract: A self-contained pre-manufactured roof top unit is used to circulate fresh air, heat or cool a building. The housing has a blower connected into a circulation system to circulate air into and out of the building. The unit has a pressure relief opening for connection into the building that is used to relieve air pressure buildup within the building. The pressure relief opening is part of a pressure relief passage that is independent of the blower and has an exhaust vent that opens and closes automatically in response to pressure differential between the building and ambient air.

Abstract: A self-contained air unit for installation on a roof top of a building has a pressure relief opening that is independent of the air circulation system of the unit. The air circulation system has a first blower and the pressure relief opening has a damper system that connects the pressure relief opening to ambient air through two passages. One of the passages contains a second blower to exhaust air from the air circulation system and from the independent pressure relief opening simultaneously. A two-stage pressure relief hood is provided for use with a self-contained air unit.

Abstract: The invention concerns a method of adjusting a room air in a first room wherein the room air is supplemented continuously or at recurring intervals of time by nitrogen or a nitrogen-bearing, carbon dioxide-poor gas mixture in such a way that the proportion of oxygen in the room air is less than 20.9% by volume and the proportion of carbon dioxide in the room air is less than 1% by volume, wherein at the same time at least a slight overpressure in relation to an outside atmosphere surrounding the room is set in the room.

Abstract: A building is disclosed, with which the air may be guided from a heat reservoir into an interspace, and/or from the interspace into the heat reservoir through conduits.