Abstract: The invention generally relates to ventilation systems and methods, and more particularly to selectively configurable climate control systems and methods for use in data centers and the like. A device includes a support element and a plurality of ducts connected to the support element. The device also includes a manifold in fluid communication with each one of the plurality of ducts and a plurality of valves. Each respective one of the plurality of valves is associated with a respective one of the plurality of ducts. Moreover, there is at least one actuator operatively connected to the plurality of valves, which is structured and arranged to individually actuate each one of the plurality of valves.

Abstract: A fan type temperature control method and device are provided. The device includes a fan unit including a plurality of fans and cooling an apparatus to be cooled, power supplies (v1,v2) supplying power for the fans in the fan unit, and a fan control unit which controls the fans as follows: when temperature t of the apparatus is lower than critical temperature t1 of a first temperature detect switch (k01), all fans stop; when t is higher than t1 and lower than critical temperature t2 of a second temperature detect switch (k02), all fans rotate at half speed; when t is higher than t2 while lower than critical temperature t3 of a third temperature detect switch (k03), a first fan part (M1) rotates at full speed and a second fan part (M2) stops; when t is higher than t3, all fans rotate at full speed.

Abstract: A critical parameter monitoring system for improving the safety of personnel working in a remotely located hazardous location possibly containing combustible materials include an oxygen and a temperature sensor carried by the personnel. The sensors are connected to a centrally located processor which displays the oxygen level and temperature present at the sensors and issues a warning when the measured parameters exceed preset levels. The monitoring system may be a part of a breathing apparatus which supplies air and voice communications from the centralized location to personnel working in a vessel purged with an inert gas. The measured oxygen level may also be used to conserve the quantity of inert gas used in the purging process while preserving the safety of the workers.

Abstract: The present invention provides an air cleansing system that removes the polluted air and controls the air temperature. This system may by optionally integrated with other systems including security, surveillance, smoke alarms and the like.

Abstract: A mixer assembly for an air-conditioning system comprising a recirculation air line, connectable to a vehicle region to be air-conditioned, to remove recirculation air from the region, and an air-conditioning air line, connectable to an air-conditioning unit to remove conditioned air from the air-conditioning unit. A first mixing region, for mixing the recirculation air with the conditioned air, is connected to the two air lines. A second mixing region, for mixing the first mixing region air with recirculation air, is connected to the recirculation air line and the first mixing region. Also, a first supply line is connected to the first mixing region to supply air from the first mixing region to a first partial region of the vehicle region, and a second supply line is connected to the second mixing region to supply air from the second mixing region to a second partial region of the vehicle region.

Abstract: A ventilation system utilizing fans to bring air into a building and/or exhaust air out of the building powered at least in part by solar panels that can be quickly and easily mounted on the building, such as on roof vents, windows, and the like adjacent to the fans. A sensor may be operatively connected to a controller or logic circuit to measure environmental factors to determine whether to activate the fans. The ventilation system is configured to be a modular device with versatile fasteners for easy installment in windows, attics, or roof tops.

Abstract: Disclosed herein is a hybrid ventilation apparatus capable of both natural and forced ventilation. In the case of a natural ventilation mode, a worm gear is rotated in a normal direction by drive force of a drive unit under control of a control unit so that a pressing member engages with a rotation guide protrusion and rotates a damper, thus opening a flow passage, and then the worm gear is reversely rotated by drive force of the drive unit to return the pressing member to its original position, thus allowing a user to rotate a roller upwards and downwards and rotate the damper so that the degree of opening of the flow passage can be adjusted. Thereby, rapid inflow of outdoor air can be blocked, and a cold graft phenomenon, in which the temperature of indoor air rapidly drops, can be prevented.

Abstract: A system for air destratification, circulation, and/or purification including an intake positioned proximate a ceiling of a space formed by a floor, a plurality of walls and the ceiling; an exhaust, positioned proximate the ceiling and separate from the intake; a fan structure comprising a motor mechanically coupled with fan blades; a first duct for coupling the intake to the fan structure; a second duct for coupling the exhaust to the fan structure; and at least one attachment for supporting the fan structure such that no additional stress is applied to the ceiling from the fan structure; wherein the fan structure moves air from the intake to the exhaust via the first and second ducts. The system may be capable of fitting within a single ceiling tile of a T-bar ceiling.

Abstract: At least one aspect of the invention is directed to a ventilation device. The ventilation device includes a frame configured to be mounted to a barrier, and a plurality of air moving devices configured to be coupled to the frame and configured to draw air from a first side of the barrier to a second side of the barrier. The ventilation unit further includes a control device coupled to the plurality of air moving devices and configured to detect an out of tolerance condition of one of the plurality of air moving devices and control another one of the plurality of air moving devices to increase airflow though the another one of the plurality of air moving devices in response to the out of tolerance condition.

Abstract: A constructed enclosure, adjacent to an interior habitable space, uses a microprocessor-based control unit to operate enclosure openings to provide a multi-layer insulation barrier containing or creating heat, or providing a radiant barrier, isolating by open air, a thermal insulating layer from warm exterior surfaces, maximizing insulation values. The enclosed space, through the use of openings, which in one embodiment are windows, skylights and dampers connected to louvers, is heated by radiant exposure or cooled by natural air flow or exhaust fan. Return air is heated upstream from a forced air heating unit by traversing ductwork heated by the enclosure and by direct solar exposure from enclosure windows. Enclosure openings to the habitable interior spaces create air displacement drawing warm air out of the interior and fresh air in through exterior windows. The energy efficient system is tailored for immediate climate specific conditions.

Abstract: A vapor mitigation system includes at least one vacuum pipe configured to collect vapors beneath a floor of a building, and a blower coupled to the at least one vacuum pipe. The blower is configured to create a vacuum under the floor of the building. The vapor mitigation system includes a controller configured to control a speed of the blower. The controller adjusts the speed of the blower in response to a level of vacuum created under the floor of the building.

Abstract: A method and apparatus for solar fan controller have been disclosed. In one version a solar fan controller (SFC) uses inputs about temperature, humidity, weather, and fan status to control a fan.

Abstract: A heat and energy recovery ventilation unit for a building, having an inside and an outside. The unit including a main body having a fresh air inlet and an indoor air outlet on one side and a fresh air outlet and an indoor air inlet on the other side and having an air to air heat exchanger within the main body and connected to each of said inlets and outlets to define respective air flow passageways for each of said indoor air and said fresh air, the heat exchanger permitting heat and energy exchange between said indoor air and said fresh air. Also included is a first variable speed blower and a second variable speed blower and at least one electronic air flow sensor to measure at least one of the air flows the air flow sensor producing at least one electronic signal related to the sensed air flow.

Abstract: The first temperature measurer measures an first air temperature in a first place and transmits a measurement result to a system controller. The second temperature measurer measures an second air temperature in a second place and transmits a measurement result to the system controller. The sucker sucks air from the first place into a duet installed in the building. The discharger discharges the air taken from the first place via the duct into the second place. The system controller determines whether it is necessary to adjust an air temperature difference between the first and second places based on the first air temperature and the second air temperature. If the system controller determines that the adjustment is necessary, the system controller orders the sucker and discharger to start operation.

Abstract: An example apparatus is provided and may comprise a housing, an electronic blade system, and a plurality of airflow management components. The housing may have an upper chamber and a lower chamber. The electronic blade system may be located between the upper chamber and the lower chamber. The plurality of airflow management components may be configured to be removable and to manage airflow in the housing.

Abstract: Apparatuses and methods are described for adjusting air flow in a forced-air delivery system.

Abstract: Airflow rates within a ventilation system are controlled using motor speed or torque and motor electric current or pressure. Fan speed or torque may be varied to compensate for differing restriction in ductwork, and may provide a constant airflow rate over a range of varying airflow restriction. Air handlers or air conditioning units may be mass produced in common configurations, and installed in different buildings or structures with different ductwork configurations. Methods operate a fan motor at a present speed or torque, sample speed or torque, sample current of the fan motor or pressure within the ventilation system, calculate a present airflow rate within the ventilation system, calculate a new input setting using the present airflow rate and a target airflow rate, change the speed or torque to the new input setting, and repeat these steps to converge on the target airflow rate, often avoiding overshoot.

Abstract: A system and method for providing a substantially constant volume exhaust or ventilation air terminal system is shown for controlling exhaust and/or return airflow rates in a system having a central fan or ventilator. The system and method permits zone-by-zone or area-by-area airflow regulation or control in non-demand areas in response to a demand or call for ventilation in demand areas. In one embodiment, the system employs at least one constant airflow controller or regulator situated in a damper. In one embodiment, a terminal houses a plurality of sub-ducts each having an airflow regulator. At least one of the sub-ducts has a damper. When the damper is open, a maximum airflow through the terminal is a sum of maximum airflow permitted by the regulators.

Abstract: An exemplary server system includes a server cabinet, a number of racks received in the server cabinet, a number of servers mounted in the racks, and a heat dissipation device. The server cabinet includes a top plate, a bottom plate, and two end plates between the top and bottom plates. Each end plate defines an opening at a top end thereof and a plurality of apertures at a bottom end thereof. The servers are stacked between the end plates of the server cabinet with a channel defined therebetween. The heat dissipation device includes an intake fan arranged under the racks with air intakes thereof facing the apertures and air outlets thereof facing the channel, and two drawing fans respectively arranged at the openings of the two end plates for exhausting heated air of the server cabinet to the exterior.

Abstract: A power system enclosure is provided. The power system enclosure includes a box, and a ventilation system. The ventilation system includes an enclosure inlet, and an enclosure exhaust. The enclosure inlet and the enclosure exhaust are disposed outside the box. The enclosure inlet is connected to the box to allow entry of air. The enclosure exhaust includes an enclosure exhaust, and one or more gas detectors. The exhaust duct is connected to the box to route gases from the box. The gas detectors are disposed in the enclosure exhaust to detect and generate a signal indicative of a presence of carbon monoxide in the gases.

Abstract: Radon detection or sensing is provided within a building automation system for a site (e.g., building or campus). As such, one or more short-term and/or long-term radon levels may be detected or monitored. The radon levels are monitored from a remote location. The building automation system may be programmed to automatically respond to a specific (e.g., unsafe) radon level and/or a change in one or more radon levels, or combinations thereof, in order to mitigate or reduce the monitored or detected radon levels. Trending, pattern comparison between radon level and other measured information, automated response, interaction or response between different radon sensors, or combinations thereof may be provided by integrating one or more radon sensors into a building automation system.

Abstract: In a system and method of controlling particulate count in a clean room having a number of compartments/zones in series, in response to a first level of energy consumption by speed adjustable fans supplying a first volume of air per unit of time to the clean room, differential air pressures are established in the clean room compartment/zone-by-compartment/zone in series from a first compartment/zone which has a requirement for the highest air pressure to a last compartment/zone which has a requirement for the lowest air pressure. In response to a second level of energy consumption by the speed adjustable fans supplying a second volume of air per unit of time to the clean room, the same differential air pressures are substantially maintained in the clean room.

Abstract: Provided is a damper structure for an enclosed derrick, which can constantly compensate and maintain a pressure of an inner space of an enclosed derrick structure. The damper structure for the enclosed derrick includes: one or more communication ducts installed in a side of the enclosed derrick; and one or more open/close dampers coupled to the communication ducts to open or close the communication ducts, whereby air is selectively supplied to or exhausted from the enclosed derrick.

Abstract: The invention is related to a method and an apparatus for controlling a ventilating system or an air conditioning system of buildings. This controlling is used predominantly in industrial real estates and serves for the establishment and maintenance of the desired room conditions. The method for controlling a ventilating system or an air conditioning system according to the invention uses the air density as the essential parameter for the controlling. The air density depends on the temperature, the air humidity and the air pressure. The air density difference between the introduced air and the room air is kept small.

Abstract: Building vents and the associated vent stacks are an emerging security challenge. The vents may run the entire length of a building, providing a direct and substantially unobstructed path for gases and devices to be introduced into a building's interior. A security apparatus for the vent(s) of a structure may include a housing that may be positioned on a vent opening, such as a vent stack, and a gas monitoring apparatus and a motion detector. The gas monitoring apparatus may be used to detect a volatile gas in the vicinity of the housing and generate an alarm or signal when a gas is detected. The motion detector may sense the removal of the security apparatus from a vent and trigger an alarm.

Abstract: Systems and methods of controlling a heating, ventilating, and air conditioning system are provided that operate according to signals returned from return air temperature sensors as well as the supply air temperature sensors. Using predetermined temperature setpoints, return temperature information, and supply temperature information, the HVAC system is configured to maintain the temperature of a room first, by the use of its cooling valve, and second and only when the capacity of the cooling valve has peaked, by use of the fan. The presently disclosed improved HVAC system operates more efficiently by avoiding unit loading hopping and minimizing power consumption.

Abstract: A method for reducing airborne contamination within a home includes installing an air-pressure control system within a window of the home, and drawing air from outside the home through the system inlet and an airflow path through the system. As it passes through the airflow path, a germicidal radiation chamber with a UV light source sterilizes the air. Additionally, filter(s) may clean the drawn air by removing particulates from the air as it passes through the filter. The method may then introduce the sterilized/cleaned air into the home through the system outlet. The sterilized/cleaned air may displace an equal volume of contaminated air within the home.

Abstract: The present invention discloses a plenum module with compartmentalized interior that is subdivided, and partitioned into separate chambers by a set of wall panels.

Abstract: The invention relates to a method for reducing a chimney draught in an upstream connected exhaust gas cleaning system consisting in immersing a chimney tube (1; 1?) provided with the open top part thereof in a bath in such a way that a liquid (condensate) collected therein forms a liquid barrier closing the exhaust gas input end of the chimney tube with respect to environment. In order to remove the exhaust gases from the upstream connected exhaust gas cleaning system, at least one part of the chimney tube cross section is exposed by lowering the liquid level under the edge thereof. Said lowering of the liquid level can be carried out by lowering the bath.

Abstract: An improved method and system for flue gas recirculation (FGR) from the ID Fan located downstream of a scrubber (or other Air Quality Control Equipment including cyclones, baghouses, etc., hereafter “AQC equipment”) back to the scrubber (or other AQC Equipment) inlet to maintain the minimum required flue gas throughput during low-load conditions, thereby eliminating the need for a separate booster fan. A flue gas recirculation duct is connected from downstream of the ID Fan to the inlet of the scrubber (or other AQC Equipment). A variable flow restrictor is placed in the duct downstream of the ID Fan for controlling pressure of the recirculated flue gas. The flow restrictor is controlled in accordance to a function of boiler load or flue gas flow to produce the required backpressure that enables the flue gas to flow through the recirculation duct back to the inlet of the scrubber (or other AQC Equipment) at low loads.

Abstract: An energy-reducing method and apparatus for retrofitting a constant volume HVAC system, with or without an economizer, that provides heating, cooling, and ventilation to occupants within a building space. The present invention includes the introduction of a programmable logic controller and variable frequency drive (VFD) that takes control of the existing fan, heating, cooling, and optional economizer operation. The controller is programmed for the reduction of fan speed in the heating and cooling modes. The reduction of the fan speed in the ventilation mode when the 100% operation is not needed saves significant energy of the existing constant volume HVAC system where the fan motor is designed to run 100% of the time. The fan speed may be further reduced upon a reduction in sensed occupancy levels of the space, such as with a CO2 sensor. Additionally, the fan speed may be reduced in the heating and/or cooling mode to further reduce energy consumption.

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: An intelligent energy saving ventilation control system capable of drastically reducing power consumption of the system. The system includes suction and exhaust ducts having a predetermined shape, a pre-filter disposed at an entry region of the suction duct, and a composite filter disposed behind the pre-filter. The system includes a fan motor disposed between the suction and exhaust ducts to linearly control an internal suction pressure in the suction duct; a turning angle motor for controlling a turning angle of the composite filter; an outdoor air sensor for measuring freshness of outdoor air, converting the measured result into an electrical signal, and outputting the signal; and a control unit for controlling operations of the turning angle motor and the fan motor in order to control an aperture angle of the composite filter and an internal pressure in the suction duct.

Abstract: In a rack system and a ventilation apparatus, the rack system includes a closed rack, a chassis and a cooling device. The chassis is installed in the closed rack; the cooling device is contained in the closed rack and disposed adjacent and parallel to the chassis; the cooling device and the chassis jointly separate an interior space of the closed rack into a cold air channel and a hot air channel; the cooling device has an air outlet and an air inlet, and the air outlet is corresponsive to the cold air channel, and the air inlet is corresponsive to the hot air channel. The cold air channel and the hot air channel can uniformly dissipate the heat generated by stacked servers inside the chassis, so that the rack system has high energy efficiency.

Abstract: A whole house ventilation control system is disclosed for a house HVAC system including a thermostat, supply and return air plenums and an HVAC fan. The thermostat selectively controls the HVAC system to maintain the desired temperature and resulting in a variable operating cycle period between successive on times. A fresh air intake duct is between an exterior intake vent and the return air plenum. A stale air exhaust duct is between the return air plenum and an exterior exhaust vent. The control system comprises a controllable intake damper in the fresh air intake duct and a controllable exhaust damper in the stale air exhaust duct. A controller is operatively connected to the house HVAC fan and the controllable dampers. The controller stores a desired fresh air exchange rate and is further adapted to predict an upcoming cycle period for a next successive operating cycle and calculating a fresh air vent timer responsive to the desired fresh air exchange rate and the predicted upcoming cycle period.

Abstract: A scrubber configuration for controlling carbon dioxide levels in a shipping container containing respiring produce is disclosed. The scrubber is made up of a curtain which includes a gas-selective membrane having a CO2/O2 selectivity ratio greater than 1:1, said curtain being positioned close to and parallel with the rear wall of said container which includes a door, said curtain forming an air-tight seal dividing the interior of the container into a plenum chamber between said membrane and the (rear wall) door, and the remainder of the container in which the produce is placed. The structure also includes an air intake means for conveying fresh air from outside the container into the plenum chamber; and an air output means for conveying air from the plenum chamber to the outside of the container. A method for controlling the carbon dioxide levels inside a shipping container is also disclosed.

Abstract: A method for controlling a ventilation system for the ventilation of an enclosure. The ventilation system includes two or more ventilation units, which each selectively and repeatedly can be controlled to establish an air flow to and/or from the enclosure. The method includes the steps of: determining information regarding operational conditions of one or more of the two or more ventilation units by measuring the air flow through or the pressure differential across the ventilation units, generating operation control data for one or more of the ventilation units from information regarding operational conditions determined for at least one other of the ventilation units, and controlling the operation of one or more of the two or more ventilation units by applying the generated operation control data. The invention further relates to a ventilation system for ventilating an enclosure.

Abstract: A ventilation system utilizing fans to bring air into a building and exhaust air out of the building using solar panels that can be quickly and easily mounted on the building, such as on roof vents, windows, and the like, with quick application fasteners adjacent to the fans. A sensor may be operatively connected to a controller or logic circuit to measure environmental factors to determine whether to activate the fans. The ventilation system is configured to be a modular device with versatile fasteners for easy installment in windows or attics without the need for modification of the building, such as cutting holes.

Abstract: An air conditioner and a method of controlling the same are disclosed herein. The method of controlling the air conditioner includes receiving an electric power rate information, and distributing an internal air from a first indoor room to a second indoor room to reduce a temperature difference between a plurality of indoor rooms. During periods of peak power rates, costs associated with operating the air conditioner may be reduced by limiting operation of the indoor and outdoor units, while adjusting the temperatures of the indoor rooms by distributing air among the plurality of the indoor rooms.

Abstract: This invention integrates energy saving lighting with energy saving HVAC (Heating, Ventilating and Air Conditioning). This system is termed by the inventor “ILAC” (Integrated Lighting and Air Conditioning). An ILAC system includes light fixtures mounted in a ceiling and, emitting lamp heat into a plenum and visible light into a room. A central computer controls both lighting and HVAC systems. In a COOL mode an HVAC unit cools the room through a supply air duct and return air duct, and the lamp heat exits the plenum through an exhaust duct. In a HEAT mode the HVAC heats the room through the same supply air duct, a ceiling-to-plenum duct carries the heated room air into the plenum, and an HVAC return air duct carries room and plenum heat back into the HVAC unit that uses less power to heat the lamp-warmed return air. In a thermostat-controlled OFF mode, warm room air convects through the ceiling duct into the plenum and exhausts through a plenum exhaust duct along with lamp-heated plenum air.

Abstract: In a one embodiment, a system includes an air conditioning unit having an enclosure, a heat exchanger disposed in the enclosure, and a plurality of louvers coupled to the enclosure. The plurality of louvers is configured to move between an open position and a closed position, and the closed position is configured to protect the heat exchanger from an environment external to the enclosure.

Abstract: The invention generally relates to ventilation systems and methods, and more particularly to selectively configurable climate control systems and methods for use in data centers and the like. A device includes a support element and a plurality of ducts connected to the support element. The device also includes a manifold in fluid communication with each one of the plurality of ducts and a plurality of valves. Each respective one of the plurality of valves is associated with a respective one of the plurality of ducts. Moreover, there is at least one actuator operatively connected to the plurality of valves, which is structured and arranged to individually actuate each one of the plurality of valves.

Abstract: A system cools a desired region, such as a walk-in cooler, by taking cool ambient outdoor air and delivering that air into the desired region. The system uses an outdoor temperature sensor so that any time the outdoor temperature falls below a desired degree, the thermostat can turn on fans and open backdraft dampers to bring in cold air. This process by-passes existing coolers, compressors and the like of an existing system, saving the user the high cost associated with conventional walk-in coolers.

Abstract: The present invention relates to a system (100) for ventilating a defined space (102), such as for example an enclosed or at least partly enclosed basement, crawlspace or attic. The system (100) comprises a control unit (110) connected to at least one inside sensor (104), at least one outside sensor (106) and a controllable fan (108), the control unit (110) being configured to operate the controllable fan (102) if the absolute humidity (AHout) outside of the defined space (102) is lower or equal to the absolute humidity (AHin) within the defined space (102), and the temperature (Tin) within the defined space (102) is above a predetermined temperature when the temperature (Tin) outside of the defined space (102) is below the temperature (Tin) within the defined space (102). Advantages of the invention include energy efficient ventilation of the defined space and a high level of protecting from moisture related problems.

Abstract: An economizer having a first air inlet, a second air inlet and an air outlet, a method of operating an economizer and a heating, ventilation and air conditioning (HVAC) system employing the economizer. In one embodiment, the economizer includes: (1) a first damper blade assembly in fluid communication with the first air inlet and the air outlet and having a first plurality of damper blades configured to move in parallel and (2) a second damper blade assembly in fluid communication with the second air inlet and the air outlet and having a second plurality of damper blades configured to move in opposition.

Abstract: The invention relates to a safety controller for an actuating drive (2.1, 2.2, 2.3) for controlling a gas flow or a liquid flow in an open-loop or closed-loop manner by means of a flap (3.1, 3.2, 3.3) or a valve, in particular in the field of heating, ventilation, and air conditioning (HVAC) systems, fire-protection systems, and/or room protection systems. A safety circuit (9.1, 9.2, 9.3) is implemented to ensure the energy supply in a safety operating mode if an electricity supply circuit (8.1, 8.2, 8.3) drops off or is lost. A control value output circuit (1.1, 1.2, 1.3) detects status signals, in particular signals of a sensor (11.1, 11.2, 11.3), and/or status parameters of a system and/or a specifiable setting of an adjustment device that can be actuated manually. The safety control value is set to one of at least two different control values (SW1, SW2, . . . ) depending on the status signals so that the safety position of the flap is determined adaptively.

Abstract: Fire-extinguishing system in an air filter system has an inlet chamber and an outlet chamber with a filter wall therebetween. The system includes a first and second sensor, a first and second fire extinguisher, and a control unit, the first sensor and the first extinguisher being disposed in the inlet chamber, the second extinguisher in an outlet chamber and the second sensor being disposed in an outlet of the outlet chamber. The control unit is connected to the first and second sensors, and to the first and second extinguishers. The control unit records a first and second fire-detection signal in the inlet chamber and the outlet, respectively; compares the first and second signals to an associated threshold value for fire; determines at which location within the inlet and outlet chamber the fire is burning, depending on the comparison; selects which of the first and at least one second extinguisher is located near the determined position, and activates one or more selected extinguishers.

Abstract: The present invention provides an air cleansing system that removes the polluted air and controls the air temperature. This system may be optionally integrated with other systems including security, surveillance, smoke alarms and the like.

Abstract: An apparatus for heating, ventilation and/or air conditioning of an interior space includes a heat exchanger core and a heating/cooling device in fluid connection with the heat exchanger core. A recirculation port is arranged between a supply air chamber and an outside air chamber. A damper is adapted to move between a first position in which the damper blocks the recirculation port and a second position in which the recirculation port is unblocked. When the damper is in the second position, at least a portion of supply air is guided to flow from the supply air chamber through the outside air chamber to the heat exchanger core so as to defrost the heat exchanger core.

Abstract: Methods and apparatus for controlling an economizer in a ventilation system based upon moisture related properties of a first input air source and a second input air source to minimize energy for conditioning air in a structure.