Abstract: An indoor air quality (IAQ) system for a building includes an IAQ sensor that is located within the building and that is configured to measure an IAQ parameter. The IAQ parameter is one of: an amount of particulate of at least a predetermined size present in air; an amount of volatile organic compounds (VOCs) present in air; and an amount of carbon dioxide present in air. A mitigation module is configured to: selectively turn on a mitigation device based on a comparison of the IAQ parameter with a first ON threshold and a second ON threshold; and selectively turn off the mitigation device based on a comparison of the IAQ parameter with an OFF threshold. A clean module is configured to determine a clean value for the IAQ parameter. A thresholds module is configured to, based on the clean value, determine the first ON threshold and the OFF threshold.

Abstract: A display case for preserving and displaying objects in a protected environment. The display case includes: a display space, delimited by separating walls including a lower plane, side walls and a ceiling; and means for adjusting and controlling air climate in the display space. The means for adjusting and controlling include: a hygrometric probe for detecting the relative humidity inside the display space: a control unit, connected to the hygrometric probe and a first relative humidity control electrolytic membrane, located in a first opening formed in one of the separating walls, activated by the control unit.

Abstract: A system and methods for the storage, and preservation of mechanical assets, including collectable automobiles, small airplanes and watercraft in a storage unit. The storage unit includes a plurality of asset modules. The volume of each asset module is variable. The atmosphere of each asset module may be controlled by a control system. Control of the atmosphere of each asset module includes control of parameters including the type of gas each atmosphere is composed of and the temperature, the pressure and relative humidity of each atmosphere. These parameters may be monitored and controlled from a remote location.

Abstract: A data center cooling system includes an evaporative cooling system. The evaporative cooling system includes fans configured to circulate outside air at ambient conditions through an entry zone of a data center, and atomizers positioned upstream of the entry zone configured to spray atomized water into the circulating outside air. The atomized water evaporates in an evaporation zone and cools the outside air to produce cooled air, which is directed through racks of computers positioned downstream of the evaporation zone.

Abstract: A vehicular air-handling system includes a blower assembly for a vehicle having a fan and a return-air baffle operable between a fresh-air position. The fan is in communication with a fresh-air duct and a recirculating position and the fan is at least partially in communication with a recirculating duct. A noise-attenuating end of the recirculating duct is positioned below an instrument panel of the vehicle and oriented substantially perpendicular to a portion of a floor below the instrument panel, wherein noise from the fan drawing air through the recirculating duct is directed into the floor below the instrument panel.

Abstract: A method is provided for supplying air conditioned air to a residence or building interior. The method entails positioning a heat and mass exchanger to discharge conditioned air into the residence or building interior. Further, a rotatable desiccant wheel dehumidifier in positioned in fluid communication with the heat and mass exchanger. Supply air is received and treated in the dehumidifier, thereby supplying dry air to the heat and mass exchanger and exhausting hot humid air. The heat and mass exchanger is positioned and configured to receive dry air from the dehumidifier and supply cooler dry air to the residence or building interior, or other target environment. A system is also provided for operating the air supplying or air conditioning method.

Abstract: A container test system includes a test chamber in which a container may be located for testing, for instance, for assessing insulative properties of a container. In the test chamber, the outside of the container is thermally treated, temperature of the air outside the container is measured, and temperature of a liquid inside the container is measured. A related testing method is also disclosed.

Abstract: An apparatus is configured to receive an incoming air stream from within an enclosure and to exhaust an outgoing air stream into the enclosure, the incoming and outgoing air streams flowing in a flow direction. The apparatus comprises an evaporator, a compressor, a condenser, and a heat exchanger. The heat exchanger has a heat extraction portion and a heat depositing portion, wherein the heat extraction portion is disposed in an air stream outside of the enclosure and wherein the heat depositing portion is disposed downstream of the evaporator with respect to the flow direction. A method includes receiving an incoming air stream from within an enclosure in a dryer apparatus, the apparatus including an evaporator, a compressor, and a condenser. A heat exchanger is operably connected to the dryer apparatus to transfer sensible heat from an air stream outside of the enclosure to a location downstream of the evaporator.

Abstract: A commercial plant cultivation system generates a controlled environment in which plants can be grown. A grow enclosure generate a controlled environment and can be either a mobile or fixed structure. A plurality of growing panels and a plurality of lighting fixtures are slidably mounted on a grow system support structure positioned within the grow enclosure. The plurality of growing panels can be positioned in either a vertical or horizontal configuration depending on the type of plants being grown. A nutrient delivery system is in fluid communication with the plurality of growing panels to deliver a nutrient solution to the plants. The nutrient solution is dispersed to the roots of the plants through a plurality of supply tubes positioned within each of the plurality of growing panels. Excess nutrient solution is collected and passed through a rock box in order to replenish nutrients and minerals.

Abstract: A system for multi-stage control of humidity in fluid flow supplied to at least one information technology apparatus includes a sensor, a first stage apparatus configured to vary humidity levels in the fluid flow, and a second stage apparatus positioned downstream of the first stage apparatus along the fluid flow to further vary humidity levels in the fluid flow. The system also includes a controller configured to receive environmental condition information from the sensor, to determine whether the information indicates that the humidity level is outside of a predetermined range, and to manipulate an operation of at least one of the first stage apparatus and the second stage apparatus to vary the humidity level in the fluid flow in response to the information indicating that the humidity level is outside of the predetermined range.

Abstract: Methods and systems are provided for controlling a defrost unit for a vehicle. A prediction is performed as to whether condensation has formed against a surface of the vehicle. The defrost unit is automatically activated when it is predicted that the condensation has formed against the surface. Another prediction is made as to whether condensation has dissipated from the surface while the defrost unit is operating. The defrost unit is automatically deactivated when it is predicted that the condensation has dissipated.

Abstract: An air conditioning system of a vehicle including a controller and sensors in communication with the controller. The sensors include an interior temperature sensor for determining the temperature of the vehicle interior and an inner surface temperature sensor for determining the temperature of the inner surface of the vehicle's windshield. The controller determines a dew-point for the vehicle interior based on the sensed interior temperature. The controller adjusts the dew-point or the inner surface temperature based on a correction value, and performs a defogging operation when the temperature of the inner surface of the windshield is less than the dew-point, wherein the dew-point or the inner surface temperature is adjusted.

Abstract: A method for controlling a vehicle HVAC system to automatically defog a windshield glass and to prevent fogging or condensation of the windshield glass. In-cabin air temperature and relative humidity are measured and used to determine a dewpoint. Further, ambient or outside temperature is measured. If windshield wipers are being used or if the cabin air temperature is less than a predetermined temperature, the ambient air temperature value is used as a glass temperature, otherwise the glass temperature is determined from the ambient air temperature and vehicle speed. A fog margin, which is a measure of the likelihood of fog formation, is based upon the difference between dewpoint and the windshield glass temperature. The fog margin is used to control the HVAC system to anticipate and respond to potential fogging conditions.

Abstract: A climate control system and method for optimizing energy consumption in a hybrid electric vehicle (HEV) is provided. By varying evaporator temperatures based on occupant settings and environmental conditions, electric compressor speed can be optimized to provide the necessary cooling capacities resulting in energy savings. Determining the impact that increasing or decreasing engine cooling fan speed has on the overall energy consumption of the climate control system without affecting target discharge air temperature provides for energy saving opportunities. Optimizing energy consumption according to the provided strategy provides for improved fuel economy without sacrificing passenger comfort.

Abstract: The present invention provides an energy efficient air conditioner that can provide a continuous supply of air at dew point that is several degrees Celsius below zero, without requiring a defrost cycle. The air conditioner in accordance to present invention comprises a plurality of cooling coils with interconnecting refrigerant piping, refrigeration circuit consisting of compressor and condenser coils, control circuit and one or more electric motor driven centrifugal fan. The present invention uses two cooling systems. The first cooling system having single coil cools the air to a temperature just above zero deg. C., say four deg. C. so that the second stage gets a steady supply of cold air. The second stage has two coils, each being half the size of the first stage coil, thus taking half the air from it so that all the air from stage 1 passes through stage 2. In operation, only one coil of the second stage is active arid chills the air going through it to say minus 14 Deg. C.

Abstract: A system and method of operating a vehicle air conditioning system having an engine driven, fixed capacity refrigerant compressor and a compressor clutch is disclosed. The method may comprises setting a preliminary evaporator air temperature target; charging a cold storage apparatus in the vehicle air conditioning system; determining if the cold storage apparatus has reached a predetermined threshold; if the cold storage apparatus has reached a predetermined threshold, determining a new evaporator air temperature target by: determining a maximum allowable dewpoint evaporator air temperature for maintaining a passenger compartment humidity below a predetermined value; determining a maximum allowable mode evaporator air temperature based on a mode to which the vehicle air conditioning system is set; and setting the evaporator air temperature target to the lower of the dewpoint evaporator air temperature and the mode evaporator air temperature.

Abstract: A system for controlling air-conditioning of a vehicle includes an input, an offset generator module, and an evaporator temperature control module. The input receives an input temperature. The offset generator module receives a psychrometric parameter of air inside the vehicle and generates offsets based on the input temperature and the psychrometric parameter. The evaporator temperature control module generates a target evaporator temperature based on the offsets.

Abstract: An optoelectronic detector and method of using same. In order to avoid any condensation on a surface, it has been known to heat such a surface. However, heating an optoelectronic detector will create a stronger hissing noise due to the greater dark current that is caused thereby. The invention is intended to avoid any condensation on an optoelectronic detector without airtight encapsulation. To this end, the detector is cooled and equipped with a sensor for the determination of a current value of one of the variables ambient humidity and ambient dew point temperature and a control unit that is connected with the sensor and designed to control the cooling device in dependence of such a value. By taking into account the ambient humidity or, respectively, the dew point temperature in the control of the cooling device, condensation on the detector can be avoided. An airtight encapsulation of the detector and the cooling device is not required.

Abstract: Systems and methods are provided for controlling humidity in gases exposed to batteries, which can be applied to humidity control in climate control gases in battery packs, for example those used in electric vehicles.

Abstract: A system and method for controlling a fan unit are described and shown. The system may comprise an electronic controller, an indoor sensor responsive to at least one characteristic of interior air, and an outdoor sensor responsive to at least one characteristic of exterior air. The electronic controller may cause at least one fan of a window fan to be activated when interior air meets certain criteria relative to a set point and exterior air meets certain criteria relative to interior air. The method may comprise the steps of measuring at least one characteristic of exterior air, at least one characteristic of interior air, and activating an intake fan when the interior air meets certain criteria relative to a set point and the exterior air meets certain criteria relative to the interior air. The fan unit may optionally include a selectively activated compressor and selectively provide air conditioning.

Abstract: A cooling system for a data center in which equipment racks are disposed has a cooling unit and a controller coupled to the cooling unit. The cooling system includes temperature sensors at or near the cooling unit's air return inlet, at or near the cooling unit's air supply outlet, and at or near the equipment racks air inlet(s). The controller measures these temperatures. A relative humidity sensor is located at or near the air return inlet of the cooling unit. The relative humidity where the relative humidity sensor is located is measured by the controller using the relative humidity sensor. The controller calculates the dew point temperature from the temperature sensor and relative humidity. Using this dew point, which is essentially constant throughout the space being conditioned, and the temperatures from the other locations, the controller then calculates the relative humidity at each location.

Abstract: Methods of providing dehumidification control in unoccupied spaces are disclosed. An illustrative method can include the steps of providing a controller having an away mode of operation adapted to provide dehumidification within the interior space of a building or room, providing one or more system components adapted to control the humidity and/or temperature within the interior space, initiating the away mode of operation within the controller, and operating the one or more system components for at least one cycle to reduce the humidity within the interior space.

Abstract: Methods of providing dehumidification control in unoccupied spaces are disclosed. An illustrative method can include the steps of providing a controller having an away mode of operation adapted to provide dehumidification within the interior space of a building or room, providing one or more system components adapted to control the humidity and/or temperature within the interior space, initiating the away mode of operation within the controller, and operating the one or more system components for at least one cycle to reduce the humidity within the interior space.

Abstract: A method for air conditioning a motor vehicle, in which, in a heating mode, the passenger compartment of the motor vehicle is heated via a passenger compartment heat exchanger (5) through heat pump operation of a refrigerating circuit (1). To prevent fogging of the windows of the motor vehicle from the outset, the temperature and humidity in the passenger compartment are recorded by measurement technology, and when the temperature is in a predefined range and the atmospheric humidity reaches a defined threshold, the mass flow of refrigerant in the circuit is throttled upstream of the passenger compartment heat exchanger (5), in such a manner that the moisture contained in the air stream passing the passenger compartment heat exchanger (5) is at least substantially condensed at the passenger compartment heat exchanger (5), and the moisture which has already condensed at the heat exchanger (5) remains at the heat exchanger (5).

Abstract: A dehumidifier system is connected to an interior space of a building through supply and return ducts, either directly and/or through an HVAC system. Controllable dampers can be used to select how the dehumidifier system is connected to the interior space and the HVAC system. The dehumidifier determines the dew point of the ambient air from temperature and relative humidity measurements taken at location(s) of relative humidity and temperature sensors. Based on the determined dew point, the dehumidifier system determines whether to operate. The temperature and relative humidity sensors can be located in the interior space or within the dehumidifier, where they project into the air stream flowing through the dehumidifier. The dehumidifier system operates in response in part to blower calls to the HVAC system and controls the HVAC system and a ventilation system to distribute the dehumidified air and outside air throughout the building.

Abstract: A method and apparatus for controlling a vehicle HVAC system to automatically defog a windshield glass and to prevent fogging or condensation of the windshield glass. The ambient air temperature and vehicle speed are measured and used to determine a windshield glass temperature. The in-cabin air temperature and relative humidity are measured and used to determine a dewpoint. An dewpoint margin is calculated to compensate for sensor accuracy and fog predictability. A fog margin, which is based upon calculated windshield glass temperature and dewpoint, is calculated and used, in conjunction with the dewpoint margin, to control the HVAC system to anticipate potential fogging conditions and to scale the intensity of the HVAC system response based upon the severity of fogging conditions.

Abstract: The present invention provides systems and methods of controlling local environment. In one embodiment, incoming air enters a contactor such the Direct Contact Cooler-Condenser (DCCC) where the air contacts water distributed on the contact media. After passing through the DCCC, the air is saturated at a temperature equal or close to that of the water. Depending on the state of the incoming air, in the DCCC will be humidified or dehumidified to yield saturated air at the desired humidity ratio. In one embodiment, a blower draws air through the DCCC and blows into the heater. The heater heats the air to the desired dry-bulb temperature. Before exiting, the air may pass through a filter.

Abstract: A window glass dew-point compartment interior absolute humidity Xrmax is acquired, and a temporary compartment interior set absolute humidity Xset (temporary Xset) is determined from a compartment interior set temperature Tset. A smaller one of Xrmax and (temporary Xset) is used as a compartment interior set absolute humidity Xset. An outlet air required absolute humidity Xao required to obtain Xset is calculated taking into account the humidity of exterior air introduced into the passenger compartment. Using Xao and an outlet air required temperature Tao required to obtain Tset, a control temperature Tea for controlling a compressor is determined.

Abstract: A method for humidifying and controlling the temperature of a process gas stream comprising the steps of super-saturating and heating the process gas stream with steam until it reaches a first pre-set temperature; cooling the process gas stream until it reaches a second pre-set temperature; removing excess condensed water from the process gas stream; and heating the process gas stream until it reaches a third pre-set temperature. An apparatus for implementing this method is also disclosed.

Abstract: A vehicle air conditioner has an air conditioning unit and an air conditioning control unit. The air conditioning unit has a FACE blowout port, a DEF blowout port, an upper blowout port. The air conditioning control unit estimates an outside windshield temperature and determines an outside dew point temperature. The control unit also controls the upper blowout port to stop blowing or not based on the estimated outside windshield temperature and the outside dew point temperature in a face mode to prevent the windshield from fogging.

Abstract: A device and method for automatically preventing misting of the windscreen of a vehicle, wherein a number of sensors determine ambient conditions capable of misting the windscreen, and, upon such ambient conditions occurring, an electronic central control unit automatically activates the air-conditioning system of the vehicle to prevent the windscreen from misting. The device has and the method utilizes a radiant mean temperature sensor arranged inside the vehicle passenger compartment to measure temperature inside the passenger compartment. The radiant mean temperature sensor (4) has a field of view including at least part of the windscreen.

Abstract: A method for humidifying and controlling the temperature of a process gas stream comprising the steps of super-saturating and heating the process gas stream with steam until it reaches a first pre-set temperature; cooling the process gas stream until it reaches a second pre-set temperature; removing excess condensed water from the process gas stream; and heating the process gas stream until it reaches a third pre-set temperature. An apparatus for implementing this method is also disclosed.

Abstract: The present invention provides systems and methods of controlling local environment. In one embodiment, incoming air enters a contactor such the Direct Contact Cooler-Condenser (DCCC) where the air contacts water distributed on the contact media. After passing through the DCCC, the air is saturated at a temperature equal or close to that of the water. Depending on the state of the incoming air, in the DCCC will be humidified or dehumidified to yield saturated air at the desired humidity ratio. In one embodiment, a blower draws air through the DCCC and blows into the heater. The heater heats the air to the desired dry-bulb temperature. Before exiting, the air may pass through a filter.

Abstract: Methods and apparatus for controlling a climate control system for an enclosure, including a controller for operating a cooling system and a humidification system. The cooling system is operated to maintain the temperature of the air within the enclosure at a specified value, and the humidification system is operated to maintain the humidity of the air within the enclosure at a specified value. Provisions are made to help ensure that the humidification system does not provide water to the air during periods when the minimum value of the temperature of the air provided by the cooling system is below the dew point temperature of the air.

Abstract: The invention concerns a method using a system (10) for heating or cooling air in a motor vehicle passenger compartment provided with a windscreen, by input into the passenger compartment air which has passed through an exchanger (12) comprised in a refrigerant loop. The invention is characterized in that it comprises steps which consist in measuring the temperature of the air leaving the exchanger (12), measuring the humidity of the air leaving the exchanger (12), determining the dew point of the air leaving the exchanger (12) based on said temperature and humidity, determining the windscreen temperature, comparing the dew point with the windscreen temperature and stopping the heating of air in the passenger compartment when the dew point is higher than the windscreen temperature.

Abstract: Outside air is treated to remove moisture before it enters the conditioned air space of a store or other building containing refrigeration furniture. The sensible air temperature and relative humidity measurements are taken to allow microprocessor calculations of the wet bulb temperature. A pair of unequal sized compressors of the HVAC system are then cycled in stages for peak efficiency and minimum compressor horsepower usage for low cost operation and minimal energy consumption both of the HVAC system and the refrigeration furniture. The wet bulb temperature is converged by the microprocessor which iterates a known polynomial approximately every 6 seconds to derive the wet bulb temperature. A time delay circuitry set at approximately 30 minutes prevents unnecessary staging of the compressors.

Abstract: Methods and apparatus for controlling a climate control system for an enclosure are described. The invention includes a controller for operating a cooling system and a humidification system. The cooling system is operated to maintain the temperature of the air within the enclosure at a specified value, and the humidification system is operated to maintain the humidity of the air within the enclosure at a specified value. Provisions are made to help ensure that the humidification system does not provide water to the air during periods when the minimum value of the temperature of the air provided by the cooling system is below the dew point temperature of the air.

Abstract: An improved vehicle climate control system in which the passenger compartment temperature and humidity are controlled without requiring a humidity sensor. The control is based on the recognition that the air temperature at the evaporator outlet represents the dew point of the air supplied to the passenger compartment, and may be specified based on the desired passenger compartment air temperature to achieve a desired relative humidity in the vehicle once the desired passenger compartment temperature has been achieved. In a first mechanization, the desired relative humidity is predetermined, and the corresponding values of evaporator outlet air temperature are determined as a function of the desired passenger compartment temperature.

Abstract: A temperature-humidity controller for a semiconductor equipment comprises a housing; an inlet pipe for introducing processing air, which has a discharging portion for flowing the air into an inner portion of the housing; a water supplying means for supplying water into the inner portion of the housing so as to contact with the processing air from the discharging portion of the inlet pipe thereby simultaneously performing dehumidifying and humidifying processes; a cooling means for cooling the water at a dew point; a heating means for heating the air at a desired temperature, which is dehumidified and humidified by the water supplying means; an outlet pipe for supplying the heated air to the semiconductor equipment.

Abstract: A method of controlling the temperature of intake air provided from outside air passing through an air-feed system only utilizes an especially low heating of the intake air while at the same time safely avoiding the formation of ice in the intake air, in order to avoid efficiency losses. A temperature setpoint formed by the sum of the dew point of the outside air and an additive margin of safety is preselected for the intake air. A temperature setpoint of not more than the sum of 0° C. and the margin of safety is advantageously preselected. A temperature-control device for carrying out the method and a gas turbine having the temperature-control device are also provided.

Abstract: An air conditioning system (10) for a passenger compartment of a motor vehicle having a windscreen comprises a first heat exchanger (14) positionable outside the passenger compartment; a second heat exchanger (18) positionable inside the passenger compartment; an expansion device (16) positioned in a first fluid passage (22) between the heat exchangers; an electronically controlled variable stroke compressor (12) for pumping fluid into the second fluid passage and either in a first direction (X) or in a second direction (Y); reverse flow means (32) in the second fluid passage for controlling the direction of the flow of fluid; first sensing means (36, 40) providing a first output signal indicative of the dewpoint temperature of the air leaving the second heat exchanger; second sensing means (53; 44,46,48) providing a second output signal indicative of the temperature of the windscreen; and control means (26,30) electrically connected to the first and second sensing means and to the compressor for receiving th

Abstract: A method is provided of determining windshield fog secondary for automatically controlling a heating, ventilation and air conditioning (HVAC) system of a vehicle. The method includes the steps of determining whether rain is occurring on a windshield of a vehicle, determining a windshield parameter as a function of the rain occurring and determining a temperature difference based on temperature within a cabin of the vehicle and ambient temperature. The method also includes the steps of determining a fog boundary based on the windshield parameter and temperature difference, determining a relative humidity based on the windshield parameter and the temperature difference and fog boundary and determining a fog probability based on the fog boundary relative humidity and a nominal base relative humidity for rain conditions. The method further includes the steps of determining anti-fog actions to be taken based on the fog probability and taking the anti-fog actions determined to control the HVAC system.

Abstract: In a main controller for use in an air conditioner for controlling temperature/humidity of an intaken outside air, a controlling line setter (18) sets each of control lines (J.sub.1 -J.sub.5) on a psychrometric chart table (13), in which an aimed temperature/humidity line (Lo) is formed by connecting an upper limit state point (Ps) and a lower limit state point (Pw) of condition air from each of the outside air state points (G.sub.1 -G.sub.5) to the aimed temperature/humidity line (Lo). The controlling line (J.sub.1 -J.sub.5) is formed by connecting necessary lines selected from a main heating line (H.sub.L) showing the heating operation of a main heater (H), an adiabatic humidifying line (W.sub.L) showing the humidifying operation of an adiabatic humidifying device (W), a cooling line (C.sub.L) showing the cooling operation of a cooler (C) and an auxiliary heating line (RH.sub.

Abstract: A temperature and humidity control apparatus includes a humidity control section for controlling humidity when a flow rate of a low temperature fluid in a cooling dehumidifier composed of a heat exchanger is determined; a heater control section for controlling temperature when a flow rate of a high temperature fluid in a heater; and a predicting device for predicting an amount of temperature change caused by an operation of the cooling dehumidifier. The amount of predicted temperature change is canceled when the flow rate of the high temperature fluid in the heater is determined in the heater control section, and the flow rate of the high temperature fluid in the heater is determined so that the setting temperature can be realized.

Abstract: A method and a system for regulating the mixed air in a heating/air-conditioning unit (1) of a motor vehicle in which fresh air and/or recirculated air are fed to a heating/air-conditioning unit (1) which controls the feeding of fresh air and/or recirculated air in the passenger compartment of the vehicle. In a method for optimizing the consumption of energy for such heating/air-conditioning systems, the feed of fresh air and/or recirculated air is so adjusted that the temperature of the dew point of the air within the vehicle is less than the temperature on the inside of a window of the vehicle.

Abstract: A method of operating an HVAC system having an HVAC control and a humidity limiting control. The method comprises the steps of: determining a relative humidity limit for a space; monitoring relative humidity in the space; comparing the relative humidity to the relative humidity limit; operating the conventional HVAC control if the space humidity does not exceed the humidity limit; and integrating the HVAC control and dehumidification controls if the space conditions require humidity limiting action.

Abstract: An air-conditioning apparatus for use in a vehicle includes bypass means for forming a bypass duct to allow the air which has passed through an evaporator to bypass an heater core, opening/closing means for opening and closing the bypass duct, and refrigerant control means for switching between a supply state in which refrigerant is supplied to the evaporator to a stop state in which the supply of the refrigerant to the evaporator is stopped based on a temperature of air having just passed through the evaporator. When it is determined that a physical amount relating to the temperature of the air introduced into a casing is greater than a predetermined amount and when the control state of the refrigerant control means is switched from the stop state to the supply state, the bypass duct is closed for a first predetermined time period by control means with the opening/closing means. In this way, it is possible to prevent the foggy air from being generated.