Abstract: A building loses or gains heat through its envelope based on the differential between the indoor and outdoor temperatures. The losses or gains are due to conduction and infiltration. Conventionally, these effects are typically estimated by performing an on-site energy audit. However, total thermal conductivity, conduction, and infiltration can be determined empirically. The number of air changes per hour are empirically measured using a CO2 concentration monitoring device, which enables the infiltration component of total thermal conductivity to be measured directly. The conduction component of thermal conductivity can then be determined by subtracting the infiltration component from the building's total thermal conductivity.

Abstract: Appropriate ventilation for a building space while maintaining building comfort includes tracking one or more interior environmental conditions within the building space and one or more exterior environmental conditions outside of the building space during operation of the HVAC system. An environmental model for the building space is learned over time based at least in part on these tracked environmental conditions, where the environmental model predicts an environmental state of the building space in response to operation of the HVAC system under various interior and exterior environmental conditions. A maximum allowed ventilation rate that can be achieved without causing the HVAC system to compromise on any of one or more comfort conditions of the building space is predicted using the environmental model. The outdoor air ventilation damper of the HVAC system is then controlled to provide an appropriate ventilation up to or at the predicted maximum allowed ventilation rate.

Abstract: A system and related method are disclosed for controlling condensation in a space. The system includes a fan and one or more sensors for sensing environmental conditions such as temperature and relative humidity associated with the space and/or objects within the space. For instance, the sensors may sense a surface temperature of an object within the room. The system also includes a controller capable of receiving measurements from the sensor(s) and controlling the fan based on the sensed information. The system may additionally include a heater and/or a damper for transferring outside air into the space, either of which may be controlled by the controller based on the measurements.

Abstract: Implementations are directed to a smart filter apparatus including an air filter, a sensor supported by the air filter and sensitive to a pathogen, and a control unit in data communication with the sensor and operable to perform operations including receiving, from the sensor, an indication of the pathogen present in air incident on the sensor, generating, by the control unit, a pathogen alert response, and providing, by the control unit, the pathogen alert response.

Abstract: Disclosed herein are a method of controlling operations of an air conditioner by analyzing a user's behavior pattern, and an air conditioner, the present disclosure according to an embodiment includes an air blower configured to discharge air, a camera configured to acquire images of a space in which an indoor unit of the air conditioner is disposed, and a control unit configured to extract features from the image acquired by the camera, to generate image descriptions, and to control the air conditioner using parameters generated in response to the image descriptions.

Abstract: A forced air handling system includes an automated monitoring system. A method of operating the automated monitoring system includes initiating a calibration mode of operation via a controller. A plurality of dampers may then close via the controller. Once closed, a duct in communication with the plurality of dampers may be pressurized. A first air flow measuring exiting each one of the plurality of dampers may be obtained by a flow sensor. The duct is then depressurized and a second airflow measurement is taken, via the controller, exiting each one of the plurality of dampers. The controller calculates a statistical difference between the first and second airflow measurements.

Abstract: 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.

Abstract: A HEPA/VOC air handling system is disclosed. It has a HEPA air filtration unit and an air handling unit. The HEPA air filtration unit has a fresh air intake, an inside air intake, a pre-filter unit, a HEPA air filter, and HEPA fan. The HEPA fan draws fresh air and inside air into a HEPA chamber to form combined air that moderates the fresh air toward the inside air's temperature and humidity to inhibit shocking or damaging the components in the HEPA air filtration unit. The combined air passes through the pre-filter unit and then the HEPA air filter to form HEPA filtered combined air.

Abstract: Embodiments of a sensor device, method and system employ a multiplicity of environmental sensors as a single monitoring and alerting mechanism, operable to provide a profile of any contaminant in terms of various gases and particles in the atmosphere, quantified in terms of relative concentrations. In various embodiments, the sensor device can comprise hardware and firmware elements, including an electronic control system, a case, a shield and a cover. The environmental sensors can be secured as part of the electronic control system and the shield can be formed so as to facilitate proper channeling of air and sound for effective operation.

Abstract: Embodiments of a sensor device, method and system employ a multiplicity of environmental sensors as a single monitoring and alerting mechanism, operable to provide a profile of any contaminant in terms of various gases and particles in the atmosphere, quantified in terms of relative concentrations. In various embodiments, the sensor device can comprise hardware and firmware elements, including an electronic control system, a case, a shield and a cover. The environmental sensors can be secured as part of the electronic control system and the shield can be formed so as to facilitate proper channeling of air and sound for effective operation.

Abstract: A ducting system has a first upstream location is to be connected to a first source of air. A downstream location in the duct is to be connected to a second source of air. The upstream location has a first valve, and the downstream location has a second valve. An end location of the duct is to be connected to a sink. A control for the valves achieves a desired pressure and temperature of air at the end location. The first temperature sensor is located at a position intermediate the upstream location and the downstream location. A second temperature sensor is located at a position intermediate the downstream location and the end location. A control is programmed to determine the health of the first and second valves based upon a difference between temperatures sensed by the first and second sensors. An air use system and a method are also disclosed.

Abstract: The present invention relates to a blower. A blower according to one embodiment of the present invention comprises: an upper fan for generating a first airflow, which is suctioned through an upper suction part and is then discharged; a lower fan disposed under the upper fan to generate a second airflow, which is suctioned through a lower suction part and is then discharged; an airflow changing device disposed between the upper fan and the lower fan to generate a third airflow by joining the first airflow and the second airflow; and a control part for controlling the rotation speed of each of the upper fan and the lower fan to adjust the discharge direction of the third airflow.

Abstract: An air conditioner and a control method thereof perform cooling through an outlet if room temperature or room humidity is high to reduce the room temperature or the room humidity, and closing the outlet to perform cooling at low velocity through an outlet hole if room temperature or room humidity reaches a predetermined value so that a user can little feel the wind velocity of cooling of the air conditioner, while maintaining indoor space at pleasant temperature or humidity. By performing cooling at low velocity through the outlet hole formed in the lower portion of the air conditioner, it is possible to cool the lower area of indoor space at pleasant temperature when a user is asleep.

Abstract: Smoke and/or soot damage to an interior of a property, such as a residential building or home, may be mitigated. A controller is in communication with a heating, ventilation, and air conditioning (HVAC) system of the property. The controller is configured to receive an alert and/or intelligent home telematics data generated based upon a potential presence of smoke in a location associated with the property, either exterior or interior to the property. In response to receiving the alert and/or intelligent home telematics data, the controller is further configured deactivate an air circulation function of the HVAC system to mitigate smoke or fire damage to the property. The intelligent home telematics data may be generated by various smoke, fire, audio, visual, infrared, motion, and/or other smart sensors mounted about the interior and/or exterior of the property.

Abstract: An embodiment of the present invention relates to a flow generating device comprising: a main body comprising a first suction part and a second suction part disposed at sides opposite to each other, a first inner discharge part through which air suctioned into the first suction part passes, a second inner discharge part through which air suctioned into the second suction part passes, and at least one outer discharge part through which air passing through the first inner discharge part and air passing through the second inner discharge part are discharged to the outside; a first fan disposed between the first suction part and the first inner discharge part; and a second fan disposed between the second suction part and the second inner discharge part.

Abstract: A circulator blower controller for a circulator blower of a heating, ventilation, and air conditioning (HVAC) system of a building includes an interface configured to receive a demand signal with an operating mode from a thermostat. A switching circuit selectively connects power to a tap of a motor of the circulator blower. A data store configured to store a mapping from a speed to the tap. For each tap, a processor observes power consumed by the circulator blower while power is connected to the tap by the switching circuit. The processor determines the mapping by sorting the taps based on observed power consumption. The processor selects a first speed based on the demand signal from the thermostat. The processor identifies a first tap from the mapping based on the first speed and generates the tap selection signal to control the switching circuit to connect power to the first tap.

Abstract: An air handling unit includes a rain hood configured to receive an air flow from an external environment surrounding the rain hood, and a sensor disposed within the rain hood and configured to monitor air flow parameters indicative of a flow rate of the air flow.

Abstract: A system includes an inlet to collect air from outside a building; an air filter coupled to the inlet; a baffle to receive air from the inlet; an actuator coupled to the baffle; one or more sensors exposed to air from the air filter to determine air quality; a controller coupled to the one or more sensors and the actuator, the controller closing the baffle if air quality is below a threshold; and an outlet positioned after the baffle to deliver air to the building.

Abstract: A flow generator according to an embodiment of the present invention includes an upper fan configured to suction upper air and generate a first airflow, an upper fan housing configured to accommodate the upper fan from a lower side thereof and comprising a first discharge part through which the suctioned upper air is discharged, a lower fan configured to suction lower air and generate a second airflow, a lower fan housing configured to accommodate the lower fan from an upper side thereof and comprising a second discharge part through which the suctioned lower air is discharged, an air guide disposed between the upper fan and the lower fan to guide generation of a third airflow in which the first airflow and the second airflow are mixed with each other, and a control unit configured to control a rotational speed of the lower fan or the upper fan to adjust a discharge direction of the third airflow, wherein the first discharge part is disposed to face the second discharge part with respect to the flow guide par

Abstract: A system and related method are disclosed for controlling condensation in a space. The system includes a fan and one or more sensors for sensing environmental conditions such as temperature and relative humidity associated with the space and/or objects within the space. For instance, the sensors may sense a surface temperature of an object within the room. The system also includes a controller capable of receiving measurements from the sensor(s) and controlling the fan based on the sensed information. The system may additionally include a heater and/or a damper for transferring outside air into the space, either of which may be controlled by the controller based on the measurements.

Abstract: Disclosed is a system and method for managing the comfort of building occupants. The system utilizes a model-based approach for targeting occupant comfort levels. The system allows for voting input from building occupants regarding their respective comfort. Additionally, the system provides a user interface to gather occupant input and use said input as a parameter in a comfort model.

Abstract: A workstation cooling system includes a radiant panel configured to be disposed in a workstation. The workstation cooling system also includes a water supply conduit configured to provide a cooling water flow to an inlet of the radiant panel and a water return conduit configured to receive the cooling water flow from an outlet of the radiant panel. The workstation cooling system additionally includes a control valve configured to receive control signals to adjust the cooling water flow provided to the radiant panel to enable the radiant panel to absorb heat to maintain a target temperature of the workstation.

Abstract: An HVAC register airflow control system and an air flow control method are provided. A housing of the system is in fluid communication with an air source for supplying an airflow. The housing includes an air outlet to the enclosed space. A detection sensor detects occupancy information of the enclosed space. A controller generates a control signal based on the occupancy information and controls the shape change of a damper made of a shape memory material. The damper is controlled to switch between a first operative configuration for preventing the airflow from entering the enclosed space and a second operative configured for permitting the airflow to enter the enclosed space.

Abstract: Disclosed is an intelligent heating, ventilation, and air conditioning (“HVAC”) system. Located within an architectural structure, the HVAC system incorporates an airborne contaminant-flow calculator. When sensors (or a human operator) detect an “incident” (e.g., a contaminant is detected or an unexpected breach occurs in the structure that may be associated with the introduction of a contaminant), the HVAC system recalculates airflows for the structure. If the newly recalculated airflow so warrants, the HVAC system protects the structure's occupants from the airborne contaminant by changing the airflow through the structure (e.g., the HVAC system closes a shutter in the air ducts, turns up a fan, or redirects airflow to a standby filtration system). The HVAC system's calculator uses a closed-form solution for calculating the airflow in order to present its results in a timely fashion.

Abstract: An apparatus includes a computer enclosure with a first fan, a second fan, a fan controller, and an input for receiving a signal from a microphone indicating an amount of noise at a target location. The apparatus further includes a first actuator coupled to the first fan for adjusting an axial position of the first fan, wherein the controller controls the operation of the first actuator to position the first fan to reduce the noise indicated by the signal from the microphone with the first and second fans in operation. The microphone senses sound pressure and the controller automatically adjusts a position of one or more fans using an actuator to change the distance from the fan to the microphone, which may be co-located with a user, to provide destructive interference at the location of the microphone.

Abstract: 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.

Abstract: The present invention includes a plurality of fan motors, first and second inverters for individually driving the fan motors, respectively, and one and a common control unit that performs a control arithmetic for each of the fan motors and generates an individual driving signal given to each of the inverters.

Abstract: An indoor air quality control system, including a plurality of fixed detectors, an unmanned vehicle platform and a cloud computing platform. The fixed detectors detect the indoor air quality at respective designated positions in an indoor area. The unmanned vehicle platform moves along a designated route in the indoor area. When an index corresponding to the indoor air quality at a designated position reaches an air pollution warning value, a processing unit of the unmanned vehicle platform controls the unmanned vehicle platform to move towards a corresponding one of the designated positions and controls an air cleaning device on the unmanned vehicle platform to perform air cleaning. The cloud computing platform receives the indoor air quality detected by the respective fixed detectors and the mobile air quality detected by a mobile detector on the unmanned vehicle platform over the Internet.

Abstract: Disclosed herein are volatile organic compound monitoring or detection systems and methods, including systems having both a reference air intake component and at least one air sample intake line. In certain embodiments, the systems provide for continuously repeating cycles of testing and calibration/recalibration. Further implementations relate to systems having two or more intake lines that can be positioned to take air samples at distances ranging from 5 feet to 200 feet or more apart.

Abstract: A venue occupant comfort system, comprises a processor that stores computer executable components stored in memory. A plurality of sensors sense ambient conditions associated with exterior and interior conditions of a venue. A context component infers or determines context of an occupant of the venue. A crowd estimation component infers, based at least in part on mining social networks, size of crowd expected at the venue. A comfort model component implicitly and explicitly trained on occupant comfort related data analyzes information from the plurality of sensors, the crowd estimation component and context component. A comfort controller adjusts environmental conditions of the venue based at least in part on output of the comfort model component. The adjustments to venue environment can optionally be differentiated by zone.

Abstract: A method and system for testing airtightness of a building envelope (10). An air flow generator (21) is provided that is switchable between at least two different flow rates (Q0,Q1). The air flow generator (21) is repeatedly switched between a first flow rate (Q0) and a second flow rate (Q1) for modulating the building pressure (P1) as a function of time (t) between respective equilibrium pressure values at the first flow rate (Q0) and the second flow rate (Q1). The relative building pressure (?P) is measured by a differential pressure transducer (31) and recorded as a function of time (t). A pressure modulation amplitude (?Pmodulation) is calculated for providing a measure of the airtightness.

Abstract: A secondary controller that controls a secondary device and is used with a primary controller that controls a primary device. The secondary controller detects primary control signals sent to or from the primary controller, and controls the secondary device based on the detection such that the secondary device does not operate when the primary device is operating, or so that the secondary device operates in a relatively lesser capacity when the primary device is operating. Also described is an outdoor air cooling and ventilation apparatus for supplying outdoor air to an indoor space, which may optionally be used with the secondary controller.

Abstract: A facility for performing setpoint adjustment-based duty cycling techniques by adjusting the setpoint of a device or component is described. The facility reduces energy consumption for a system, such as an HVAC system, or device by adjusting or modulating an associated setpoint or temperature setting. The facility modulates the setpoint between a base setpoint value and another setpoint value based on a mode of the system. When the system is in a cooling mode, the facility modulates the temperature between the base setpoint value and a higher setpoint value. When the system is in heating mode, the facility modulates the temperature between the base setpoint value and a lower setpoint value. The facility may modulate the setpoint between the two setpoint values based on an offset value or a fixed setpoint value.

Abstract: An indoor environment model creation device is configured to create an indoor environment model of an indoor space in which air-conditioning equipment configured to condition air, an indoor humidity sensor configured to measure an indoor humidity of the indoor space, and a CO2 sensor configured to measure a CO2 concentration in the indoor space are installed. The indoor environment model includes a plurality of physics models in which heat, moisture, and CO2 concentration parameters are included. The indoor environment model creation device includes: a data storage unit configured to store operation data of the air-conditioning equipment in a learning target period as learning-use input data, and store measurement data measured by the CO2 sensor and the humidity sensor; and a model parameter learning unit configured to comprehensively learn the plurality of physics models with use of the learning-use input data and the measurement data, which are stored in the data storage unit.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency by computing the power consumed in various configurations and selecting the configuration requiring minimum power to operate.

Abstract: A cooling system circulates cooling air through information technology (IT) modules within a large scale information handling system (IHS). An air handling unit (AHU) directs cooling air through an IT module. The AHU is in communication with a controller. The controller is also in communication with an ambient condition interface to determine a level of a contaminant in outside air. The controller further: determines whether the level of the contaminant exceeds a threshold; and in response to determining that the level of the contaminant exceeds the threshold, configures the AHU to perform a mechanical cooling mode that excludes the outside air by recirculating air within an IT module via the AHU. In response to the level of contaminants not exceeding the threshold and other detected ambient conditions are favorable to using outside air to cool the IHS, the controller configures the AHU to use outside air.

Abstract: A method for air purification is disclosed, comprising directing air through a particle removal filter that acts to filter the air for particle phase pollutants to thereby produce particulate filtered air; and directing an amount of the particulate filtered air through a gas removal filter that acts to filter the particulate filtered air for gas phase pollutants to thereby produce gas filtered air; the particle removal filter with the first blower and the gas removal filter with the second blower are housed in different enclosures and they are allowed to operate in a way that; the two different units are selectable to operate separately without connection in a first mode, and to operate together connectively in a second mode; when the two different units are selected to operate together connectively in the second mode, the amount of particulate filtered air directed through the gas removal filter is based on a concentration of particle phase pollutants in the air.

Abstract: An air conditioning system includes a climatic beam located in a room. The climatic beam includes a first portion and a second portion, and a divider located along a length of the climatic beam to separate the first portion from the second portion. The climatic beam further includes a coil supplied with a flow of fluid. A fresh air duct is connected to the first portion to provide a flow of fresh air into the first portion, and a fan is located at the second portion and is configured to draw a flow of primary air across the coil and into the second portion. A beam exit allows a flow of the fresh air and the primary air into the room.

Abstract: Described herein is an air handling unit that includes canopies for compressor fans and exhaust fans located on a top thereof, which canopies provide for noise abatement and a canopy to assist in keeping precipitation out. The canopies further include louvers that can be controlled to provide for even further noise abatement and precipitation control.

Abstract: A method for controlling a climate control system is disclosed. In one example, the climate control system includes an air mixing valve that is adjusted in response to a energy conversion device load demand. The method may provide improved climate control in a vehicle cabin during high energy conversion device load conditions.

Abstract: Methods and systems for modifying resources equipped to manage loss events and processing associated therewith based on an analysis of real-time data. An insurance provider can maintain historical data that indicates resources usage data for managing previously-occurring loss events. The insurance provider can receive real-time first-party and third-party loss event data from a variety of sources, the loss event data being associated with a recent or forecasted loss event. The insurance provider can compare the received loss event data to the historical data to determine that resources configured to manage insurance claim processing resulting from the loss event may need to be modified. In embodiments, the resources may be hardware or software resources, a workforce, physical goods or supplies, or other resources. The insurance provider can facilitate the appropriate resource modification by interfacing with various components and entities.

Abstract: A computer-implemented method, a computer program product and a device for the condition monitoring of a component or system, such as for an aircraft or spacecraft. The method includes: providing an optimized decision tree, the nodes of which contain attributes of an input vector, the leaves of which each contain a classification function and the connections of which between the nodes are weighted; providing an input vector derived from a data signal; implementing a condition monitoring in which the condition of the component or system is determined using the weighted decision tree and on the basis of the input vector. In addition to an item of information concerning which of the classification functions of the decision tree best corresponds to the input vector, an additional item of information concerning the probability with which the other classes of the decision tree correspond to the examined input vector is calculated and output.

Abstract: While cooling operation is continued, a compressor is stopped when a detection temperature Tm reaches a control temperature Tc that is a lower temperature than a set temperature Ts only by a bias temperature ?Tb, and rotation of a turbofan is stopped if a human body is not present in a room R, or the rotation of the turbofan is continued and a value of the detection temperature Tm is corrected to a correction detection temperature Ta that is a lower temperature than the detection temperature Tm only by a predetermined temperature correction amount ?Tm. While the correction detection temperature Ta is a temperature that is equal to or lower than the set temperature Ts (the control temperature Tc for prevention of hunting) (Ta=Tm??Tm?Tc), the rotation of the turbofan is continued as long as a person is present in the room R, and thermo ON is resumed if the correction detection temperature Ta exceeds the set temperature Ts (Ta>Ts).

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: A measuring device of air flow rate for an air conditioning system which accurately measures the flow rate of cooling air blowing out of the openings of some rectangular units and in which the locations of the openings can be changed according to the location of equipment. The measuring system includes a plurality of panels constituting a floor surface, ceiling surface, or wall surface, a rectangular vent unit with openings located in place of a given one of the panels, a space with a given height formed by pillars on the back sides of the rectangular vent unit and the panels, and an air conditioner for supplying cooking air to the space. The cooling air from the space passes through the openings. A measuring means for measuring the flow rate of cooling air passing through the openings is located in a rib which forms the openings.

Abstract: A ventilation system for a building in some cases includes a main HVAC blower for moving temperature-conditioned air through the building plus a smaller ventilation blower for providing fresh air. A controller regulates the ventilation blower's speed to provide a target ventilation flow rate regardless of changes in the pressure differential between the indoor and outdoor air. To ensure that the target rate is appropriate for a particular building, the target flow rate is determined based on a ventilation setting that reflects a specified number of bedrooms and a specified amount of floor space of the building.

Abstract: An installation for cooling an electronic device includes an air conditioner having an air outlet for blowing cooling air to a room; a first detector adjacent to the air outlet of the air conditioner, for detecting a temperature of the cooling air; a rack accommodating the electronic device, the rack having an air inlet for receiving the cooling air from the air conditioner and an air outlet for exhausting air to the room; a second detector adjacent to the air inlet of the rack, for detecting a temperature of air received through the air inlet of the rack; and a controller for acquiring the temperatures detected by the first and the second detectors, and controlling a quantity of the cooling air blown from the air outlet of the air conditioner so as to decrease a difference between the temperatures detected by the first and the second detectors.

Abstract: An air conditioning controller includes a supply air temperature controller controlling a temperature of supply air provided to an air conditioner so a supply air temperature measurement value matches a supply air temperature setting value; a total air volume device measuring/calculating a total supply air volume value that is the total of the air volumes to each individual variable air volume unit; a supply air volume controller controlling an air volume of supply air to the air conditioner, depending on the total air volume value; an air volume insufficiency evaluator evaluating if the air volume is insufficient by comparing the total air volume value to a total air volume lower limit value; and a supply air temperature setter changing the supply air temperature setting value in a direction that the variable air volume unit increase the air volume, when there is an evaluation that the air volume is insufficient.

Abstract: A method performed by a zone controller for a zone of a building for improving energy efficiency in a heating, ventilation, and air conditioning (HVAC) system is provided. The method includes operating in a ventilation mode. A temperature of the zone and outside air conditions for the building are monitored. A determination is made regarding whether to switch from the ventilation mode to an economizing mode based on a first set point for the temperature of the zone and based on the outside air conditions. The first set point is determined based on a second set point for the temperature that is different from the first set point. A determination is made regarding whether to activate the HVAC system based on the second set point.

Abstract: A system and method of heating or cooling a room of a building provides supplemental warmer or cooler air to the room with an inline duct supplemental heating and cooling device mounted along an air duct that supplies the room with air from a main furnace and/or cooling unit associated with the building. A thermostat is used to set a desired temperature for the room, and a controller of the supplemental heating and cooling device is in communication with the thermostat, and activates an electric heater and/or fan as appropriate to warm or cool the room as needed. When the device is used to cool the room, the fan may be operated to draw cooled air through the duct from the main cooling unit and/or from other areas in the building that are linked via ductwork.