Abstract: A fogger array, permanent wash down filters, and a digital controller for use in a heating, ventilating and air conditioning system having sensors and controls, the heating, ventilating and air conditioning system having a return air and a supply air plenum, the return air plenum is baffled to the outside, an outside air source with baffles, a mixed air plenum, the mixed air plenum connected by baffles to the outside air source and the return air plenum, characterized by the fogger array located in the mixed air plenum, the permanent wash down filters located in the supply air plenum proximate the mixed air plenum, the permanent wash down filters located in the supply air plenum proximate the fogger array, the digital controller controlling the sensors and controls to the heating, ventilating and air conditioning system and fogger array.
Abstract: A housing, particularly of a vehicle headlamp, has aeration of its interior housing space via at least one hole for admission and/or exiting of air flows, wherein a switch apparatus, that changes a cross section of flow as a function of humidity of the air, is positioned in the at least one hole to move automatically from a closed position into an open position and vice versa. A method for aerating the interior space of the housing involves air entering the interior housing space via at least one air admission hole and exiting the interior housing space via at least one air exit hole, with aeration occurring only if condensation is present in the interior housing space and if a humidity of the entering air is lower than a humidity of the air in the interior housing space.
Abstract: A combination miniature golf club bag and humidor for cigars positioned centrally in the golf bag. The humidor carryall in the form of a miniature golf bag may be decoratively displayed when not in use, but all the while storing and humidifying cigars contained therein.
Abstract: A highly reliable electronic apparatus free from condensation in the cabinet of the apparatus. The electronic apparatus has printed circuit boards on which heat emitting semiconductor devices are mounted and a fan. The electronic apparatus further comprises a hygrometer for measuring the relative humidity and dew-point temperature of the cooling air that is introduced into the cabinet through an opening, a surface temperature sensor for sensing the temperature of the surface of the semiconductor devices, an internal temperature sensor for sensing the internal temperature of the semiconductor device, dehumidifier and heater means made up of a heat pump and an outdoor unit, and a controller for controlling the dehumidifier means and the heater means so that the relative humidity is less than 100% and the dew-point temperature is less than the surface temperature of the semiconductor devices.
Abstract: The electric lock system combines an electric lock with an energy control unit such that when a guest key is used in the lock, the lock communicates with the energy control unit to move from an unsold state to a sold state. Optionally, the guest key has information which tells the lock when the guest will leave and the lock communicates to the energy control unit to move from the sold state to an unsold state. Another option, includes a motion detector and door switch which allows the lock to detect the presence of the guest in the room and allows the lock to further employ an occupied and unoccupied state. The combination of the electric lock system and the energy control unit provides energy savings in the heating and cooling of the room.
Abstract: An overhead installed communication system includes a cabinet body which includes an electronic circuit device and a door which is supported by the cabinet body through a hinge so that the door can be opened and closed. The system is installed overhead and external cables are introduced into the system. A box is provided inside the door, and the box is sealed in a condition where a lid is closed. A connector is provided in the box, electric wires extending from the electronic circuit device are connected to the connector and the external cables are connected to the connector after being introduced into the system.
October 15, 1997
Date of Patent:
July 27, 1999
Naoya Yamazaki, Yasushi Kojima, Hisato Sato
Abstract: A controller for an HVAC system incoporates humidity and carbon monoxide measurements in its control of the system. System cycling may be inhibited by high humidity. A portion of the system may be turned off by high carbon monoxide concentration.
Abstract: A controller for a climate control system has a relative humidity sensor as well as a dry-bulb temperature sensor within the enclosure. The humidity value is used in conjunction with the dry-bulb temperature to generate an apparent temperature error signal which is a function of both the dry-bulb temperature and the relative humidity values. This permits robust control of both enclosure temperature and enclosure moisture content without abnormal cycling of the climate control system. Instead of using a sensor which directly measures the apparent temperature, the apparent temperature can be synthesized from the relative humidity and dry-bulb temperature within the enclosure. Alternately, the sensed and set point apparent temperature values can be synthesized from any two thermodynamic properties of the moist air within the enclosure.
Abstract: A method and thermostat for controlling comfort in an area with temperature altering equipment, but no specific humidity altering equipment. An on-off thermostat which mechanically combines temperature and humidity measurements in a predetermined ratio based on a user's perception of comfort. The thermostat does not require an anticipator when used with an air conditioner in a warm and humid climate.
Abstract: At the time of dehumidifying operation, a motor-operated expansion valve is controlled so that evaporation of a refrigerant will be completed in an auxiliary indoor heat exchanger which constitutes an indoor heat exchanger together with a main indoor heat exchanger. A louver is operated to form an air passage through which air discharged from the outlet port of an indoor unit flows to the inlet port. Owing to the formation of such an air passage from the outlet to the inlet port of the indoor unit, dehumidification is performed with outlet air kept from reaching the living space in the room.
Abstract: There is disclosed a peristaltic pump which comprises a flexible tube for the passage of a fluid having an inlet and an outlet and a roller assembly comprising a number of rollers and a rotatable support, the rollers being mounted on and extending substantially perpendicularly outward from the rotatable support and the tube being stretched over the roller assembly so that it extends substantially perpendicularly to the rollers and through substantially 360.degree. around the roller assembly and where the tube contacts a roller it is compressed against that roller, the arrangement being such that in use where the tube is compressed against a roller it is occluded and rotation of the roller assembly causes each roller to contact and thereby occlude successive parts of the tube forcing fluid contained in the tube and trapped between the occlusions to be moved along the tube from the inlet towards the outlet.
Abstract: The invention is directed to an apparatus for determining the mist concentration in a humidified air flow of a ventilating device, preferably a ventilating or air-conditioning installation. It is characterized by a plurality of moisture precipitation elements (12) having different geometrical dimensions which are arranged in the air flow (2) and are provided with a moisture sensor device (9). The invention is further directed to an air washer for humidifying an air flow in a ventilating installation.
August 31, 1993
Date of Patent:
March 7, 1995
LTG Lufttechnische Gesellschaft mit beschrankter Haftung
Abstract: An automatic control method for an air conditioner which can optimize the indoor temperature and humidity, wherein an adequate dehumidifying operation is performed by recognizing the humidity according to the weather based on the outdoor temperature changes preceived by the outdoor temperature sensor for a certain time period, which provides comfortable surroundings and increases the efficiency of the air conditioner as well by preventing apparatus freeze resulting from a prolonged dehumidifying operation under low temperatures.
Abstract: The present invention provides a process for decreasing the relative humidity of a gaseous or vaporous process stream, while increasing the temperature thereof. A preferred embodiment of the process of the present invention is implemented using a bleed valve, a positive displacement blower located downstream therefrom, and a control mechanism for opening and closing the bleed valve. When opened, the bleed valve preferably permits ambient air to admix with the gaseous process feed stream to form the blower feed stream. Increased blower gas throughput results in a lower magnitude gas temperature increase across the blower. The control mechanism used in the practice of the present invention involves monitoring the temperature of the blower effluent (or the gaseous feed to a downstream unit operation), and controlling operation of the bleed valve in accordance with that temperature reading.
Abstract: The present ventilating system is used for homes and buildings located in cold climate areas. The system includes a heat exchanger for extracting heat from the inside air discharged to the exterior and transferring said heat to the outside air admitted into the building. Blowers circulate air through the two paths of the heat exchanger and a motorized damper on the outside air path closes or opens the same. An integrated circuit and the following sensors serve to operate the system as follows: sensors detect the concentration of air contaminants, the humidity and the negative pressure of the air inside the building, while an outside air temperature sensor is also provided. When the level of air contaminants is above an adjustable preset level, the system operates in an inside air upgrading mode, namely air is circulated in both paths of the air exchanger; the same mode is used where humidity level is found to be excessive.
Abstract: Method and apparatus for controlling the dew point in a reaction vessel in which a dew point reading is converted to an electric current signal which is coordinated with a preselected dew point range and translated into a frequency which is transmitted to a device that regulates the addition of liquid water to the reaction vessel.
Abstract: The humidity of a heated space is regulated by varying the amount of moisture transferred from the combustion gases of the furnace used to heat the space. A porous heat sink element is arranged to move through the path of the combustion gases and one or more reclaim-air paths. The heat sink member can take any of a variety of forms; it can reciprocate back and forth along a track, or it can be configured as a rotating wheel ("heat wheel"). The amount of moisture transferred from the combustion gases to the reclaim air is governed by a humidity signal. If the humidity signal calls for a change in humidity, one of several parameters is varied to provide for a greater or lesser transfer of moisture from the combustion gases to the reclaim air.
Abstract: A spray booth for applying a coating to a substrate includes an outer chamber (12) containing a fluid therein having a predetermined first temperature and/or humidity and an inner chamber (14) in fluid communication with the outer chamber (12). The inner chamber (14) contains the fluid therein at a higher predetermined second humidity and/or temperature. The inner chamber (14) includes a fan (42) for recirculating a flow of the fluid at the second predetermined temperature and/or humidity therethrough and filters (34,36,44,46) for removing airborne comtaminants. A temperature and/or humidity control device (58) exhausts a predetermined amount of the fluid from the inner chamber (14) out of the inner (14) and outer chambers (12) said exhausted fluid being essentially free of toxic contaminants, the exhaust of the fluid drawing fluid from the outer chamber (22) into the inner chamber (14) to lower the temperature and/or humidity in the inner chamber (14).
Abstract: A cooling apparatus for cooling a given device which is incorporated in a computer or similar electronic equipment and generates heat by circulating a liquid coolant through the device of interest. A secondary cooling liquid exchanges heat with a primary cooling liquid in a heat exchanger and then flows into the device of the equipment. When the difference in temperature between the secondary cooling liquid and the interior of the equipment decreases beyond a predetermined value, a heat exchanging mechanism is caused to stop operating. On the increase of the difference in temperature beyond the predetermined value, the heat exchanging mechanism is caused to begin operating again. Alternatively, the operation of a secondary cooling liquid feeding mechanism may be interrupted and then set up again on the basis for the above-mentioned difference in temperature.
Abstract: There is provided a magnetic recording device including recording mediums and an airtight enclosure containing the recording mediums therein and having a fine breathing hole created therethrough communicating with the outside thereof, wherein at least two types of moisture adsorbents composed of a one way type moisture adsorbent which adsorbs moisture and a reversible type moisture adsorbent which adsorbs moisture in high humidity and conversely discharges the same in low humidity are disposed in the cabinet and used in combination. There is also provided the same device except wherein gas adsorbents and moisture adsorbents are used in combination.
Abstract: A humidity generating method and apparatus which utilizes a source of air which can be supplied to a saturator and to a drier for supplying wet and dry air streams. Control means are provided to control a cyclical supplying of alternating timed quantities of wet and dry air streams to a chamber to provide a mixed air stream having a desired relative humidity.
Abstract: There is described an analyzer for determining analytes of a body liquid, in which stacks of test elements are stored prior to use. To control the level of humidity in which the stacks are stored, first and second compartments are provided with access openings connecting them to the stack-storage area. A mechanism is provided for selectively closing off and opening up the access openings, and for actively forcing air to flow from either of the compartments into the storage area. One of the compartments has a supply of water, and the other has a desiccant.
Abstract: In a television receiver which is installed in a high-humidity environment such as a bath room, a main body of a television receiver and a dehumidifier are placed in a container case provided with a waterproof structure, and a drain pipe is connected to the dehumidifier for discharging water generated in the dehumidification operation to the outside of the container case.
Abstract: Apparatus for regulating the humidity inside a semi-sealed, partly air-permeable container for a magnetic disk drive. An opening provided in the semi-sealed container is sealed by an insulated humidity regulating element which includes a hydrogen ion conductor (which may be a solid electrolyte) and porous film-like first and second electrodes that are bonded to respective surfaces of both sides of the hydrogen ion conductor. A DC voltage is impressed across both electrodes to regulate the humidity.
Abstract: A method of controlling climate in an interior of a vehicle, which method comprises the steps of measuring air temperature in the vehicle interior and outside of the vehicle, measuring relative humidity in the vehicle interior and outside of the vehicle, and controlling air flow from outside of the vehicle into the vehicle interior in accordance with the measured temperatures and humidities.
December 16, 1988
Date of Patent:
June 12, 1990
Robert Bosch GmbH
Horst Fedter, Werner Grunwald, Peter Nolting
Abstract: An air control device, having a panel which opens and closes in response to changes in environmental conditions in a building, preferably is sized to replace a ceiling tile in a conventional drop ceiling. The air control device may be responsive, for example, to a change in temperature of the air space above a conventional drop ceiling, raising the panel when the temperature drops to near freezing, allowing air from below the drop ceiling to commingle with air above the drop ceiling. A support in rolling contact with the underside of the panel maintains the panel open, the support including a fusible fire link which fails or fractures in the event of a fire, thus allowing the panel to fall, insuring that the fire rating of the ceiling is not compromised.
Abstract: A humidifying system for maintaining the moisture content of the paper at a preferred level in an electrostatic plotter. The plotter has a paper supply compartment rotatably holding a horizontal roll of plotting paper where the paper passes from the roll and through the supply compartment to a separate printing compartment. There is a powered piezoelectric humidifier for supplying cool water vapor at an outlet opening thereof. An adjustable humidistat is disposed in the paper supply compartment and operatively connected to turn the humidifier on and off as a function of the humidity in the paper supply compartment. A plastic pipe manifold is horizontally disposed across the inside of the paper supply compartment. The manifold has a closed end and an opposite end connected to the outlet opening of the humidifier. The manifold has a plurality of spaced outlet holes through sidewalls thereof along the length thereof for water vapor introduced into the manifold by the humidifier to emerge therefrom.
Abstract: A magnetic disc device includes a moisture removing mechanism within an enclosure of the device. The mechanism employs a reversible desiccating agent which is capable of not only absorbing moisture but also discharging moisture depending on the surrounding conditions. The reversible desiccating agent cyclically absorbs and discharges moisture in response to a change in temperature and a change in humidity due to the intrusion of the moisture from outside the enclosure. The moisture removing mechanism can be used for a long period of time with a small amount of desiccating agent. Thus, it is possible to make the moisture removing mechanism small and to provide it with long life.
October 29, 1987
Date of Patent:
May 16, 1989
Mitsubishi Denki Kabushiki Kaisha
Masatoshi Kakuda, Chiaki Kawamura, Hiroshi Baba
Abstract: A dehumidifier includes a humidistat switch to provide power to the compressor and fan when the ambient humidity exceeds a given level. The power to the compressor is also controlled by a thermostat switch and a timer. When the dehumidifier is operating in an environment that is below a given temperature, the compressor is periodically turned off for a short interval to melt any ice that has formed on the compressor coils.
Abstract: An air conditioning system is disclosed which employs an air washer for treating variable volumes of air moving through the air washer per unit of time. The air washer includes a moisture eliminator that is provided with means for changing its effective face area in response to changes in the volume of air moving through the air washer per unit of time.
August 4, 1986
Date of Patent:
March 15, 1988
R. J. Reynolds Tobacco Co.
Richard P. Lortie, Philippe H. Vercaemert, Douglas L. Gunnell
Abstract: A system for controlling the temperature and humidity of an enclosure such as a museum display case continuously extracts air from the enclosure, increases its humidity, cools it to a controlled temperature, at which point its humidity is 100%. The air is then heated and returned to the enclosure. By selection of the controlled temperature the relative humidity of the returned air may be determined.
Abstract: A vaporizing humidifier includes a portion for providing stepwise increases and decreases in vapor output capacity in response to the duration of a vapor demand signal, for matching the vapor output to the demand therefore.
Abstract: The humidity within a chamber is controlled by injecting pulses of steam therein, the duty cycle of the steam pulse input being increased when the humidity of the chamber is lower than desired and decreased when the humidity of the chamber is higher than desired. Each steam pulse is generated by injecting a pulse of water through a small inlet tube into a steam generator comprising a tank surrounded by a band heater, the tank being preheated to a high temperature such that the water quickly turns to steam as it is injected. The steam is then vented into the aforementioned chamber. A detector, mounted within the chamber, produces a signal of magnitude proportional to the relative humidity in the chamber and this signal is input to a control circuit for producing a pulse width modulated control signal of duty cycle varying with the difference between the magnitude of the humidity sensor signal and an adjustable set point signal.
Abstract: A disk drive is provided with a vent tube which is long (i.e., 20 inches) compared to its bore (i.e., 0.013 inch) to minimize diffusion of water vapor into the drive without seriously affecting pressure gradients along the length. Minimum bore diameters are given for specified lengths of vent tube. Conveniently, a desiccant is employed with a heater to absorb water vapor admitted to the drive and to expel water vapor when the drive is operated. A thermally-operated valve is also employed to expel water vapor when the drive operates. The desiccant may be employed in a chamber separated from the disk chamber, whereupon pressure valves are provided to adjust the pressures in the drive.
Abstract: A control system for an electrically energized humidifier used with a hot-air furnace including an electric time-delay circuit and control means for manually adjusting the time delay. Each time the thermostat for the system energizes the furnace the humidifier is energized for the predetermined time delay or until the furnace is de-energized, whichever occurs first. The time delay is manually adjusted so that it is longer than the energization cycle of the furnace in warm weather and shorter than the energization cycle of the furnace in cold weather. It is also manually adjusted so that in cold weather at the maximum energization cycle, the humifidier does not produce condensation within the building. The relative humidity of the conditioned air thus decreases proportionately to increases in the atmospheric temperature.
Abstract: A method for production of a moisture sensor comprising forming a moisture sensitive polymer film on a substrate, disposing a patterned masking material on said moisture sensitive polymer film, and etching said moisture sensitive film by means of an oxygen plasma, whereby a desired fine pattern of the moisture sensitive film is formed with fair accuracy and reproducibility.
Abstract: A computer cooling system has a mixing valve which supplies coolant to the computer and receives hot return coolant from the computer and also chilled return coolant from a chiller intermediate the computer and the mixing valve. The mixing valve mixes the hot return coolant with the chilled return coolant to adjust the cooling system temperature. Control circuitry senses, or estimates, the dew point temperature of the computer room environment, compares it with the cooling system temperature, and adjusts the mixing valve to maintain the cooling system temperature a few degrees above the dew point temperature. A condensation sensor comprises of a light emitting diode (LED), reflective tape applied about a cooling system supply conduit, and a phototransistor is disclosed. Light from the LED is fully reflected by the reflective tape to the phototransistor in dry conditions, but only partially reflected when condensation forms on the tape.
Abstract: A device for determining the concentration of condensable vapor in a flowing gas stream which includes a gas evacuation conduit for receiving a sample of gas from the stream, a gas condenser in the evacuation conduit for condensing out essentially all of the condensable vapors in the sample and a gas flowmeter connected to the gas discharge of the gas condenser for determining the flow of the dry gas sample exiting the condenser. A pump is provided for withdrawing a sample of gas from the flowing gas stream and for conveying this sample at a constant, known volumetric flow through conduit and to the gas condenser and the flowmeter and a control means operatively connected to the flowmeter determines the condensable vapor concentration by comparing the flow of the dry gas sample with the known volumetric flow fed to the condenser.
Abstract: An auxiliary air cooling unit cools and dehumidifies air entering an air-conditioned building. The auxiliary unit operates in response to increased temperature and/or moisture content of the outside air to prevent air of undesirably high moisture content from entering the building. As the auxiliary unit operates selectively during periods of increased cooling load, it avoids or reduces problems of over-cooling of the air in the building by the main air-conditioning unit and reduces the need for periods of inefficient reduced-power operation of the main unit.
Abstract: Air conditioning apparatus for conditioning the air supplied to a vehicle passenger space is provided which includes an air conditioning air cooling evaporator and an air heater unit arranged in series. An evaporator bypass duct extends in bypassing relationship to the evaporator and a heater bypass duct extends in bypassing relationship to the heater. To control the temperature of the air conditioned by the apparatus two temperature mixing air flaps are provided, one air flap controlling the proportion of air flow through the evaporator and its bypass duct and the other air flap controlling the proportion of air through the heater and its bypass duct.
April 17, 1981
Date of Patent:
June 12, 1984
Suddeutsche Kuhlerfabrik Julius Fr. Behr GmbH & Co. KG
Abstract: A variable thermostat-type air conditioning system for an automotive vehicle passenger compartment has a dehumidification switch. When a driver depresses the dehumidification switch the compressor begins to operate as if the temperature-adjusting lever were set to the extreme COOL end. Therefore, it is possible to dehumidify or cool the passenger compartment without adjusting the temperature-adjusting lever which is already set to an appropriate lever position. The air-conditioning system according to the present invention comprises a temperature-sensitive element, a variable resistor linked to the temperature-adjusting lever, the dehumidification switch to short the variable resistor, and a thermocontrol amplifier, in addition to a standard compressor, evaporator, etc.
Abstract: Apparatus for controlling humidity comprises a humidity sensing circuit including a humidity sensing element the electrostatic capacitance of which varies in accordance with the ambient relative humidity, and an air-conditioning system responsive to the sensed humidity. The humidity sensing element is charged and discharged repeatedly in accordance with a pulse train signal, and a period required for the voltage across the sensing element is measured during charging by a comparison between the voltage and a reference voltage. The pulse width or the reference voltage may be changed to select a desired reference humidity. A hysteresis characteristic may be given to render the operation of the circuit stable. When an SCR is controlled by the output signal of the humidity sensing circuit, the frequency of the pulse train signal is selected to be greater than four times the frequency of the voltage applied to the SCR.
Abstract: A humidifier adapted to be associated with a grand piano to facilitate the control of humidity conditions and which also can be used to humidify any small enclosed area. The humidifier includes a tank having a supply of water therein, a heating element and evaporator pads disposed at the top of the tank and a unique supporting assembly for the tank to support the tank from the top of the braces or posts in a grand piano or between the rim and an adjacent brace or posts or between the rims with the supporting structure including support rods and clips or telescoping tube assemblies. A distribution shield or baffle having depending skirts is disposed above the tank and supported from the support rods or tubes and extends throughout the length and width of the tank so that it will spread moisture more evenly in relation to the components of the piano.
Abstract: A humidity-measuring device used with an air conditioner provided with an interior heat exchanger and refrigerant pipe which comprises:a first sensor which is provided at an inlet of the interior heat exchanger and produces a first output signal denoting a temperature of air streams drawn into the interior heat exchanger;a heat conductor positioned in a state extending to the inlet at one end of that portion of the refrigerant pipe, through which the refrigerant flows with a low pressure;a second sensor which is disposed in that portion of the heat conductor which faces the inlet and produces a second output signal; anda system controller which is provided with a memory for storing data on the air humidity corresponding to the first and second output signals, and measures the humidity of the sucked air from the data stored in the memory in accordance with the first and second output signals from the first and second sensors.
Abstract: A control system for a humidifier, associated with a hot air furnace, that attains a high level of relative humidity without causing any condensation on the building interior by varying the level of operation of the humidifier as a function of the rate of heat loss from the building. Since the duty cycle of the furnace is a function of the rate of the heat loss, the system generates a digital signal related to the duty cycle and uses that signal to interrogate a digital memory storing a program of desired humidities for various duty cycles to output an instantaneous desired humidity signal which is compared with a measured humidity signal to develop an on/off control signal for the humidifier.
Abstract: In a magnetic memory device wherein a magnetic recording medium is rotated in a substantially closed chamber, there are provided a throttle between the inside and outside of the chamber, a first air fliter for filtering air flowing through the throttle to prevent moisture from entering into the chamber by diffusion, a container containing a desiccating agent and communicated with the chamber, and a second air filter located between the desiccating agent container and the chamber. In a modified embodiment, another throttle is also provided between the desiccating agent container and the substantially closed chamber.
October 1, 1979
Date of Patent:
December 22, 1981
Nippon Telegraph & Telephone Public Corporation
Abstract: The electrical energy flowing between a power source and a furnace blower motor is sensed for controlling the operation of a humidifier. A removable current sensor is connected without damaging or disfiguring the connecting lead being sensed. A solid state switch operatively connects the humidifier to a power source in response to the sensed current and is electrically isolated from the current sensor. The control circuit provides a time delay in the energization and the de-energization of the humidifier and is responsive to the current flow in the sensed lead.
Abstract: The rotary drum humidifier is mounted in an opening in the horizontal supply duct of a forced warm air furnace. The humidifier has a built-in manual humidity control wherein an adjustable thermostat is connected in series in the electrical humidifier motor circuit. The thermostat completes the electrical circuit on rising temperature in the duct and senses the peaks and valleys of the modulating duct temperature caused by the furnace heating cycle. When the control knob of the thermostat is set on "high", the humidifier will operate at a greater percentage of the furnace heating cycle and when set on "low" the humidifier will operate at a lesser percentage of the furnace heating cycle.
Abstract: A solid state electronic controller for humidification devices employs an electronic humidity sensor to create an electronic signal proportional to the humidity in the space to be controlled, and massages or processes this proportional signal to create a cyclic series of time-proportioned control signals to cause the operation of the humidification devices in each cycle for a period proportional to the difference between the sensed humidity and the desired humidity.