FIELD OF THE INVENTION:

The present invention relates to humidifier systems and more particularly to a cold evaporative humidifier system that monitors conditions of various performance parameters of the cold evaporative humidifier system and indicates the status of various components for improving overall performance of the cold evaporative humidifier system.

BACKGROUND OF THE INVENTION:

Humidifiers have been found to be very useful in raising the humidity of air present inside homes, particularly during periods of very dry weather or in winter, when outside air with low temperature is drawn inside a home, causing the relative humidity within the home to be lowered to an uncomfortable level. Under these circumstances, it is beneficial to introduce moisture into the air. Several types of humidifiers used for increasing humidity in a room or enclosures are well-known in the art. Examples of these include steam-type humidifiers, ultrasonic humidifiers, warm-air humidifiers and evaporative humidifiers. Evaporative humidifiers, also known as "cold" evaporative humidifier or "wick" humidifier, are well known in the prior art. Humidifiers are devices designed to increase humidity (moisture) of the air by emitting an invisible / visible cloud of cooled water vapor. The humidifier mentioned in the prior art generally includes a fan assembly and a wick assembly. The wick is a filter that absorbs water from the reservoir and provides a larger surface area for evaporation. The fan blows air or sucks air from the wick positioned in proximity, to aid in the evaporation of the water as disclosed in the prior art. It is noted that the manufacturers of such humidification system ship a packaging including few subassemblies to a customer. The customer has to assemble the components according to the instruction manuals. The components assembled in a standard frame of a humidifier are generally, media, tank, cables, pipes etc. During the assembly there are chances of error, for example, it is observed that many users assemble the media without removing the polythene cover provided on the media. In such case the system fails to give the designed performance. Cold evaporative systems in the prior art fail to give any indication or signal of improper installation of media or any other components of the system.

Attempts have been made in the prior art to monitor the status of the humidification media in the cold evaporative systems. For example, US patent no. 5,800,741 to Glenn et al. discloses an evaporative humidifier having a wick filter with color change indicator. The wick change indicator changes color after a period of use. As noted in the specification at Column 9, Lines 45-53, although the life of the wick filter is estimated to be approximately 6 weeks, the water supply can have an adverse effect on the color change indicator disclosed. Humidifiers in the prior art do not detect amount of un-used water occupied by the humidification wick, hence they fail to check performance or replacement of humidification wick. Humidifiers mainly apply electromechanical and mechanical switch based mechanisms for controlling the humidification process. However, the humidifiers in the prior art fail to consider the mechanical linkage tolerances involved and end up compromising accuracy of the system.

It has been observed that the humidifiers in the art fail to indicate the performance problems with humidification system. It is further observed that the humidifiers in the prior art mainly focus only one of the performance parameters at a time, for example, water content, life of media, breakdown of the appliance etc. Whereas after carefully studying the state of art of the evaporators, it can be understood that there are number of parameters that can affect the performance of the evaporative coolers. All of the performance measures, if monitored carefully can improve the overall performance of the system.

There is a need of a cold evaporative humidifier system that monitors availability of water in the sump/tank using temperature and/or relative humidity indicators. A cold evaporative humidifier system is further needed that can monitor the presence of humidification media in the humidifier system. A humidifier system is also needed that can provide indication of performance of the humidification media.

SUMMARY

A cold evaporative humidifier system for monitoring and indicating performance of the system is disclosed that has a control pane, at least two air temperature sensing elements, a PCBA, and a plurality of predefined modes of operation of the cold evaporative humidifier system. The control panel includes a plurality of LEDs and a plurality of buttons such that the LEDs indicate status of water level, and status of the humidification media in accordance with the present invention. The buttons are provided in the panel to switch on/off, the appliance, to select the desired speed setting. The buttons also facilitate resuming the operation of the system from a predefined mode of operation in which the system is stopped for some predefined reason.

The two air temperature sensing elements in the cold evaporative humidifier system monitor a wet air temperature and a dry air temperature. A dry air sensing element senses the temperature of the inlet air, and a wet air sensing element senses the temperature of the outlet air. A humidity sensing element along with the dry air temperature sensing element, monitors the RH % of the dry /inlet/ atmospheric air. The PCBA including a microprocessor is advantageously configured preferably by programming the microprocessor for determining various events that determine the status of system related to the water level, and the status of the humidification media in accordance with the inputs from the air temperature sensing elements. The cold evaporative humidifier system is operable in various predefined modes of operation that are advantageously defined in accordance with the status of the water level and the status of the humidification media of the system. A mode 'A' defines the normal mode of operation, a mode 'B' defines the status of moisture in the humidification media, a mode 'C identifies empty water tank and stops a motor, a mode 'D' identifies the humidification media on the verge of expiry, a mode Έ' identifies the humidification media if expired, and a mode 'F' identifying failure of the motor.

The dry air temperature sensing element is located in the path of dry air to measure the temperature of the inlet air for determining the temperature of the dry inlet air. The wet air temperature sensing element is positions in a path of the wet air for measuring temperature of humid outlet air. The control panel includes a mode C reset button and a mode E reset button.

The control panel includes a first LED having a blinking status in the mode 'B' for further indicating that the humidification media has started getting dry. The first LED is has a continuously glowing status indicating the mode 'C of operation for further indicating that the water tank is being empty and the motor has stopped.

The control panel includes a second LED having a blinking mode indicating the mode 'D' of operation for further indicating that the humidification media is about to expire. The second LED has a continuously ON state that indicates the mode 'E' of operation for further indicating that the humidification media has expired. The control panel includes a third LED having a continuously ON status which indicates the mode F of operation and further indicates failure of the motor, it is to be noted that the mode C also indicates an improper installation of the humidification media or absence of the humidification media.

The system of the present invention is smart system wherein a user is guided to take appropriate actions to have optimum performance from the system. The system monitoring is advantageously conducted by the temperature levels of the dry air and the wet air in the system and humidity of the dry air thereby inventing a relation of behavior of the system. The deviation in the system operation is advantageously implied to determine the status of the water level or the moisture content in the humidification media. Further, the temperature and the behavior of the system is used to determine if the humidification media is properly installed or not, or if the humidification is not installed in the system.

BRIEF DESCRIPTION OF DRAWINGS:

The above mentioned features, aspects and advantages of the present invention will be better understood with regard to following description, appended claims and accompanying drawings, wherein like reference numerals refer to similar parts throughout the several figures where:

FIG. 1A is a top perspective view of a preferred embodiment of a smart cold evaporative humidifier constructed in accordance with the present invention; FIG. IB is an exploded view of the smart cold evaporative humidifier of FIG. 1A;

FIG. 2 is a block diagram of a PCBA of the cold evaporative humidifier of FIG. 1 A;

FIG. 3 is a perspective view of a panel of the cold evaporative humidifier of FIG. 1 A;

FIGS. 4A-4B is a flow chart showing steps involved in an operational cycle of the cold evaporative humidifier of FIG. 1A; FIG. 5 is a temperature-time graph showing behaviour of the evaporative humidifier system of FIG. 1 A with time on an X axis and temperature on Y axis; and

FIG. 6 is a flow chart showing steps involved in an operational cycle in accordance with another embodiment of the present invention. DESCRIPTION OF THE INVENTION:

Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention. Referring to FIGS. 1A, and IB, a smart cold evaporative humidifier system 100 in accordance with a preferred embodiment of the present invention is described. The smart cold evaporative humidifier system 100 includes a casing 102, a humidification media 104, a fan 106, a motor 108, a temperature sensing element 1 10, a PCB assembly 112, a microprocessor 114 and a water tank 1 16. The smart cold evaporative humidifier system 100 also includes a control panel 1 17 having various indicators and controls. The humidification media 104, the fan 106, and the motor 108 are positioned at predefined locations along an axis-X, inside the casing 102, in accordance with the present invention. The temperature sensing element 110 is a dry air temperature sensing element in this one particular embodiment. This sensing element 110 monitors the temperature profile of dry air preferably of inlet and/or surrounding air temperature starting from Tl to T4.

The casing 102 defines the body of the smart cold evaporative humidifier system 100. The casing 102 includes a front cover 120, a rear cover 122 and a top cover 124. The front cover 120 includes a plurality of outlet vents 126 and the rear cover 122 includes a plurality of inlet vents 128. The top cover 124 is openable relative the body of casing 102. The top cover 124 has at least two positions. In a first position, the top cover 124 is closed. In a second position, the top cover 124 is opened. Referring from the front cover 120 to the rear cover 122, the media 104, the fan 106, and the motor 108 are positioned respectively along the axis-X. In this preferred embodiment, the most desired system specifications include capacity of the tank 1 16, water holding capacity of the humidification media 104, and a humidification rate thereof. The humidification rate is preferably considered at the standard conditions. The standard conditions are generally 20°C {+1-2) DBT (Dry bulb temperature) and 30% (+/- 3) RH (Relative humidity). For example, in the preferred embodiment, the useful capacity of the tank 1 16 of the smart cold evaporative humidifier system 100 is 2 liters, the water holding capacity of the media 104 is 400 ml, and the humidification rate of the system 100 is 200 ml/hour at standard conditions of 20°C DBT (Dry bulb temperature and 30% RH (Relative humidity).

Referring to FIGS. 2 and 3, a PCBA (Printed Circuit Board Assembly) 112 includes a mains input connector 202, a humidity sensing element 204, the dry air temperature sensing element 110, the microprocessor 1 14, and a humid/wet air temperature sensing element 208. The PCBA 1 12 also includes a mains cord 210, a plurality of LEDs, a plurality of reset buttons, and a power button 212.

The reset buttons include a mode C button 214 and a mode E button 216 in this one particular embodiment. A button 218 is provided which is a speed selection button. The PCBA 1 12 further includes a humid air temperature sensing connector 220 and a dry air temperature sensing connector 222 that connect the wet air sensing element and dry air sensing element respectively.

The PCBA 1 12 has a power ON/OFF LED 224, a speed LED 226, a first LED 228(mode B/C), a second LED 230 (mode D/E), and a third 232 LED (mode F) and a motor connector 234. The first LED 228 indicates operation in mode B or mode C. The second LED 230 indicates the operation in mode D or mode E. The third LED 232 indicates operation in accordance with mode F. In case of the first LED 228 and second LED 230, the indication is decided on the basis of the nature of continuous-lighting or blinking of the respective LEDs. The mains cord 210 has an end that is connected to the mains input connector 202. Mains input to the PCBA 112 are connected through the mains connector 202. It is understood here that the LEDs 224-232 are positioned on the panel 117 (Ref. FIG. 2) as illustrated. It is understood, however, that although a physical interface of the various buttons and LEDs is on the panel 117 (See FIG. 2), the buttons and LEDs logically define various parts of the PCBA 1 12.

The microprocessor 114 collects the signals from the predefined components of the smart cold evaporative humidifier system 100 to execute prewritten instruction codes stored into the memory. The microprocessor 114 compares signals from respective peripherals, and takes appropriate action in accordance with the logic in the code and execute the operation of the smart cold evaporative humidifier system 100. The microprocessor 114 includes a memory and a plurality of embedded programs. The plurality of embedded programs facilitates execution of different steps. However, it is understood that features and specifications of microprocessor 1 14 may vary in other alternative embodiments defined by the intended use and/or specification. The microprocessor 114 collects a plurality of feedback data from sensory elements, for example, 204, 208 and 110 to generate a series of feedback with assistance from embedded programs to execute the predefined operations such that humidity sensing element 204 measures %RH of the dry air at the inlet vents 128, the wet temperature sensing element 208 measures the DBT of the wet air at outlet vents 126, and the dry air temperature sensing element 110 measures the DBT of the dry air at the inlet vents 128.

A motor connector 234 is preferably provided with a plurality of motor-wires. The humid air temperature sensing connector 220 is connected with the humid air sensing element 208. The dry air temperature sensing connector 222 is connected with the dry air sensing element 110. The dry air temperature sensing element 1 10 is advantageously positioned in the path of the dry air that enters in the system 100. The dry temperature sensing element 110, in this one preferred embodiment is positioned between the inlet vents 128 and the fan 106. Alternatively, in another embodiment, the sensing element 1 10 is positionable after the fan 106 and before the humidification media 104. The dry air temperature sensing element 1 10 measures the temperature of the inlet air to the smart cold evaporative humidifier system 100. The inlet air to the humidifier system 100. is relatively dry as compared to the outlet air.

The wet air temperature sensing element 208 is advantageously positioned in the path of the moist/wet air. In this preferred embodiment, the humid/wet air temperature sensing element 208 is placed after the humidification media 104, in the air path of the humid air. The wet air temperature sensing element 208 is used to measure the outlet air temperature of the smart cold evaporative humidifier system 100. It is to be noted that the outlet air is relatively wet /moist with respect to the inlet air. The end of the mains cord 210 is connected to mains input connector 202. The mains cord 210 performs function of connecting the system 100 with the supply mains. It is to be noted that the air at the inlet vents 128 is relatively dry with respect to the outlet air at outlet vents 126 when the system 100 runs in accordance with a- mode A disclosed in the present invention.

The power ON/OFF LED 224 indicates if the appliance is switched ON/OFF, for example, while the smart cold evaporative humidifier system 100 is operating, the LED 224 is ON. In this embodiment, there are at least two LEDs that indicate the speed and the smart cold evaporative humidifier system 100 has two speed settings. The number of speed LEDs may vary with the possible speed settings for the smart cold evaporative humidifier system The status of the LEDs (228, 230,232) is related to the mode of operation of the smart cold evaporative humidifier system 100. For example, if the mode B is in operation, then the first LED 228 blinks, however, if the mode C is in operation then the first LED 228 remains continuously ON, if the mode D is in operation, then the second LED 230 blinks, if mode E is in operation then the second LED 230 remains continuously ON, if mode F is applicable then the third LED 232 remains continuously ON.

In the present embodiment the flow of air is from Rear Cover 122 towards Front Cover 120 with the rotation of motor 108 in clockwise direction when viewed from Front Cover 120. Alternatively, the system 100 can also work when the motor 108 rotates in opposite direction i.e anti-clockwise when viewed from the Front cover 120. Under such., condition, the air will flow from Front cover 120 towards the Rear Cover 122. The positions of the sensing element 110 and 208 will have to be interchanged and the sensing element 204 will also have to be placed along new position of 1 10.

Referring to FIGS. 4A-4B, steps involved in the operation of the microprocessor 1 14 in accordance with the present invention are described. The operation of the system 100 starts in a first mode A in a first step 400. In the step 400, a counter is reset to a values zero and the control goes to a next step. In a second step 402, if the time is equal to a predefined time tl, for example, tl=300 seconds, then the control goes to a next step 404, where the temperatures of inlet air and outlet air are noted. If the time t in the step 402 is less than the predefined limit tl then the control is passed to step 406 where the value of t is reset such that t = t + 60, and the control goes to step 408. Now in the step 408 where the Tdry and T _we t are recorded after the delay, for example, 1 minute (60 seconds) of step 406, and the control further goes to step 402 again. In the next step 404, Tdry and T _we t are recorded by the microprocessor 1 14 and the control is shifted to a next step 410. In the step 410, Tdry and T _wet are compared for a further decision. If (T _wet < Tdry) is "N" then the control goes to a next step 412 wherein mode C is executed in a plurality of steps. Whereas, if (T _wet < Tdry ) is Ύ', the control goes to another step 414. In the step 412, the mode C is executed in accordance with the present invention wherein the microprocessor 114 activates the first LED 228 which starts lighting continuously and the motor 108 is stopped immediately. The continuous lighting of first LED 228 is an indication that the water tank 1 16 and the humidification media 104 are completely dry.

Now, in the step 414, a value M is alculated wherein M= [(T _we t/ _C - T _we t/ _p )/2] where wet c is the current temperature of the wet air at outlet vents 126, and T _wet y _p is the temperature of the immediately previous temperature measurement cycle having temperatures T _wet and Tdry. It is understood that the M is the slope of the temperature profile for mode B. In a next step 416, if M >X1 is 'Υ' then the control goes to step 418 where mode B is executed. In step 418 the LED 228 starts blinking and then control goes to step 419. If (M >X1) is "N" then the control directly passes to step 419. In the step 416, XI is a predefined value, for example, XI =0.06. Value of XI depends upon the system parameters like water holding capacity of the humidifying media 104 and also upon the humidification rate of the system 100. The value XI i.e 0.06 is decided in the preferred embodiment. However, it can be any other value depending upon the operating conditions and desired value of system performance. It is, understood, however that the predefined value of XI which 0.06 is changeable during the microprocessor programming in accordance with the present invention. In step 419, if [(T _dry - T _wet > 3.5) = Ύ'] then mode A is executed in step 420 and the control is passed to step 422 where after predetermine time t (for example, t = 120 seconds) control goes to step 404. If [(T _dry - T _wet > 3.5) = ' '], the control goes to step 424. In step 424, if (Tdry - Twet > =3.0) is 'Y' then mode D is executed in step 426, where LED 230 starts blinking and the control goes to step 422. In the step 424, if (Tdry - Twet > = 3.0) is 'N' then the control goes to step 428 wherein the mode E is executed in which LED 230 is switched ON and the motor is switched OFF.

The predefined value 3.5 is determined to arrive at a decision of the change of the humidification media 104 during the operation of the system 100. With a good humidification media 104, the drop in DBT of the wet air at the outlet vents 126 is approximately 7°C at operating conditions of 30°C and 50%RH of the dry air at inlet vents 128. Assuming, a minimum of 50% drop in performance of the system 100 which is 7°C to 3.5°C the value 3.5 is decided in the preferred embodiment. However, it can be any other value depending upon the operating conditions and desired value of system performance. It is, understood, however that the predefined value 3.5 is changeable during the microprocessor programming in accordance with the present invention.

In step 426, LED 230 starts blinking to indicate that the life of humidification media 104 is coming to an end. In step 428, the LED 230 is switched ON to indicate that the performance of the humidification media 104 has dropped significantly, which further signifies that the media 104 needs to be changed with a new approximately identical media 104 with immediate effect. The motor 108 is stopped by the microprocessor 1 14 in this step 428.

Referring to FIG. 5, an operational behaviour of a smart cold evaporative humidifier system 100 is shown. The initial temperature of the wet air (out let air) is very close to that of the dry air (inlet air), for example, Tl . As the operation starts, the wet air temperature gradually drops until the temperature drops to a value, for example, T2. The difference (delta) between Tl and T2 generally depends upon the percentage RH (relative humidity), DBT Tl, amount of the air flow, and the thermal efficiency of the overall system 100. The slope of the line T1-T2 is negative and further until the point T2' the system 100 advantageously runs in mode A of the present invention wherein the quantity of the water in the tank 1 16 is sufficient and the condition of the media 104 is good.

When the wet air temperature at the outlet vents 126 starts rising from T2' to T4, the slope of the line T2'-T4 is substantially higher than that of the slop of line T2-T2'. The system 100 now operates in the mode B in accordance with the present invention wherein the LED 228 starts blinking to indicate the user to refill the tank 1 16 before the system 100 enters in the mode C which is indicated by the point T4 on the line T2'-T4. The point T4 signifies the mode C wherein the motor is immediately stopped by the microprocessor 114 and the LED 228 is turned continuously ON. T2 slowly tends to increase in a completely close /sealed room due to at least two reasons. Firstly, as the surrounding room temperature starts dropping with operation of the evaporator and secondly, due to the increase in surrounding air %RH with the use of cold evaporative humidifier. The slope of this increase in T2 is much smaller than in mode B. If the room is very big and there is ventilation of the air then T2' is same as T2. When the water in the media 104 starts reducing, it is observed that the temperature

(DBT) of the wet air starts rising until it reaches a predefined value T3 which is slightly higher than the surrounding temperature at that instant which is T4. After continuous use, Tl drops to T4 which is the temperature of the surrounding of the humidifi cation system under consideration. Whereas T5 is a theoretical value which is equal to Tl. This phenomenon is advantageously exploited in the system of the present invention to monitor the performance of the smart cold evaporative humidifier system 100 as well as to monitor the level of water, installation status of the humidification media 104, life of the humidification media 104 and the like as illustrated in the present invention with FIGS. (1-5). For example, in an experiment using the present system 100, it is observed that, if the inlet temperature is 30°C Dry Bulb Temperature (DBT) and the RH (relative humidity) is 30% then the T2 can typically be as low as 23°C.

Referring to FIG. 1 to 5, in operation, a user plugs the smart cold evaporative humidifier system 100 to the power supply. The user presses the power ON-OFF switch. Now the motor 108 runs and operation starts. The motor 108 turns ON so as to rotate the fan 106. The dry air from the surrounding is sucked by the blades of the fan 106. Before passing through the fan 106, the dry air passes over the dry temperature sensing element 110 and the humidity sensing element 204 installed in the path. The air then passes through the humidification media 104 which provides a larger surface of contact between the dry air and' the water absorbed into the humidification media 104 by the means of capillary action. The dry bulb temperature (DBT) of the dry air drops as the air inside the system 100 picks u the moisture from the water in the humidification media 104.

In a first normal mode A, the operation of system 100 is executed in at least two phases. It is to be noted that initially the water tank 1 16 is full, and the humidification media 104 is completely soaked with water. Air starts flowing through the inlet vents 128 of the rear cover 122. The dry temperature sensing element 110 senses the dry air temperature (Tdry) and the humidity sensing element 204 senses the %RH as the air flows through the rear cover 122, before getting into the fan 106. Air continuously advantageously passes through the fan 106. Now the air temperature starts building to 0.2 to 0.5°C depending upon the various parameters associated with the fan such as speed (RPM) of the fan 106, air flow, fan blade profile, and the fan blade friction. Dry air passes through the humidification media 104 which is soaked with water. The first phase starts with the switched ON position of the system until the humidification media 104 is soaked with water. In a second phase, the dry air picks up the moisture as the dry air flows through the humidification media 104. Now the air gradually becomes humid and the temperature (Dry bulb temperature) drops down (Refer line T1-T2 of FIG. 5). The drop may generally vary from 2°C to 6°C at standard DBT of 20°C and 30% RH , depending upon the constraints of the system 100. The humid air temperature at the outlet vents 126 starts dropping and the humidity starts to increase. The outlet-air temperature and the humidity are saturated after initial running of few minutes which can be up to approximately five minutes.

The microprocessor 114 notes the difference in the dry air and humid air temperature based upon the signal provided by the temperature sensing elements 1 10 and 208. After soaking operation in phase 1, the delta increases (Refer line T1-T2 of FIG. 5) during initial running of the smart cold evaporative humidifier system 100 and then gradually gets stable (Refer line T2-T2' of FIG. 5). The temperature delta being in healthy condition, the microprocessor 114, compares the value with the predefined value (Refer FIGS. 4A-B). Since the detected value is higher than the defined value, the microprocessor 114 allows the smart cold evaporative humidifier system 100 to run un-interrupted.

The operation of the smart cold evaporative humidifier system 100, in a mode B (Refer line T2'-T4 of FIG. 5) where the humidification media 104 is about to dry is discussed. In such a situation, the water tank 116 is almost empty. Ultimately the humidification media 104 is on the verge of getting dry, however, the motor 108 is still running. In the mode B, the second phase, the dry air is passed through the humidification media 104 which is gradually becoming dry. Since the humidification media 104 is getting dry, the moisture picked-up by the air reduces and the drop in dry bulb temperature also reduces. In other words, the outlet air temperature at the outlet vents 126 starts rising, however, the outlet temperature is still lower than the dry air temperature at the inlet (Refer line T2'-T4 of FIG. 5). Since the delta between dry and humid air is less than the predefined value, but the temperature of the humid air is lower than the dry inlet air, alternatively if the slope, of the line T2'-T4 (Ref. Fig. 5) is greater than XI which typically is 0.06 then the LED 228 on the control panel 117 starts blinking which indicates that the humidification media 104 is getting dry since the water tank 116 should be refilled. Now the user adds water into the water tank 1 16, and on filling sufficient quantity of water, the LED 228 stops blinking and the humidifier system 100 starts running in the second phase of the mode A and leads an uninterrupted operation.

In one more mode C, the humidification media 104 is completely dry and the water tank 116 is empty. Although the humidification media 104 is dry, the motor 108 is running and hence the dry air passes through the humidification media 104 which is also dry. Since the humidification media 104 is dry, the air flowing through the humidification media 104 fails to pick-up any moisture and also the dry bulb temperatures increases. As a result the flowing air continues to remain dry. The diy bulb temperature of the air increases due to friction over the fan blades. Since outlet air temperature is higher or equal to the inlet air temperature, depending upon the location of sensing element 110 before or after the fan 106, the microprocessor 114 gives signal and the LED 228 starts continuously glowing. The microprocessor 114 stops the motor 108 and the operation of the humidifier system 100 is stopped. The user needs to add water and to reset the humidifier system 100 by pressing reset button 214. Now the phase two of the mode A comes into action and the uninterrupted operation takes place. In one more mode D, the humidification media performance starts deteriorating, however, even if the water tank 116 is full of water. It is to be noted that even if the water in the tank 116 is sufficient, the system 100 operates in mode D because the drop in the temperature is less than the predefined value 3.50 which has been defined in accordance with the operating conditions of 30°C DBT and 50% RH of the dry air at the inlet vents 128. Now the humidification media 104 is also wet and motor 108 is running normally. The drop in DBT of the wet air as compared to DBT of the dry air is lower than that was achieved in the second phase of the first mode A. The microprocessor 1 14 detects the difference in drop of DBT of the wet air, and gives a signal to the LED 230 which starts blinking. The blinking of LED 230 is an indication to the user to replace the humidification media 104. If this continues further, the drop in DBT of the wet air further reduces that leads to another mode E. whereas, if the user changes the humidification media 104, the system 100 starts operating normally as per the phase two of the mode A.

Now in the mode E, the performance of the humidification media continues to deteriorate in a situation where the water tank 116 even if full of water and humidification media 104 is also wet. When the motor 108 runs in normal mode of operation of the humidifier system 100, the drop in DBT of the wet air as compared to the DBT of dry air is lower than previously achieved when the system 100 was running in accordance with mode D. The microprocessor 114 detects the difference in drop of DBT of the wet air. The microprocessor 114 gives signal to the LED 230 which starts to glow. This is an indication to the user to replace the humidification media 104 on immediate basis. Power to the motor is disconnected by microprocessor 114 and the appliance stops functioning. After changing the humidification media 104, user preferably needs to unlock the humidifier system 100 by pressing the reset button 216 and the system 100 starts operating afresh.

In another mode F, while the humidifier system 100 is working in a normal mode of operation as per mode A or in mode B or in mode D, the microprocessor 1 14 monitors the power consumed by the humidifier system 100. If the power consumed by the humidifier system 100 is approximately equal to the standby power of the humidifier system 100, the microprocessor 1 14 gives the signal to the LED 232; and the LED 232 starts glowing. This is an indication of a failure of the motor 108 of the humidifier system 100.

A case of an improper installation of the humidification media 104 is advantageously considered in the operation of the present invention. For example, if the protective packaging material provided over the media 104 is not removed from the humidification media 104 before installing it into the system 100 or if the humidification media 104 is absent in the system 100, the operation of the system takes place as per mode C. If the humidification media 104 is not installed, then the dry air never comes in contact with the water and the dry air fails to pick up the moisture. Under such conditions, the temperature status is same as that of in the mode C. If a protective cover on the humidification media 104 is not removed then the water is not absorbed by the media 104, the dry air is blocked and the fan 106 keeps rotating without much air flow. There is very small amount of air that flows out of the system 100. The dry air does not pick up any moisture. The wet air temperature sensing element 208 and the dry air temperature sensing element 110 behave in a similar way as in mode C.

Hence if the protective cover from the humidification media 104 is not removed or the humidification media is not installed then the dry air does not get in contact with the water and hence there is no evaporation of water. This leads the system 100 to operate in the mode C.

To fill water in the tank 116, the user has to pull the water tank 116 slightly outward and fill the tank 116 till a predefined mark. Then the user has to push the tank 116 back to the normal position. The humidification media 104 is removable and replaceable.

In a preferred method of changing the humidification media 104, the user has to first disconnect the appliance from the mains. In a next step, open the top cover 124. In the next step, pull from top the humidification media frame with the help of the hand grip and change the humidification media. Now in the next step, the frame is pushed in the normal position, and top cover 124 is locked. In a next step, reset button 216 is required to be pressed. Now the humidifier system 100 starts working afresh.

It is to be noted that in operational use of the system 100, the user has to only switch the product ON/OFF button 212 and select the operating speed by pressing button 218. The first reset button 214 is required to re-activate the system 100 and to enable the motor 108 to run after the user has added water in the water tank 116 in accordance with mode C. The first reset button 214 is preferably pressed when the system 100 operates in the Mode C. In the mode C, the user notices that the LED 228 is ON and in accordance with the present invention refills the tank 116, and then presses the first reset button 214 that informs the system 100 to start afresh.

The second reset button 216 is preferably pressed when the system 100 operates in the Mode E. In the mode E, the user notices that the LED 230 is ON, and in accordance with the present invention changes the humidification media 104 with a new approximately identical media 104, and then presses the second reset button 216 that informs the system 100 to start afresh. It is to be noted that the second reset button 216 is required to re-activate the system 100 and enable the motor 108 to run after the user has changed the new humidification media 104. The button 218 allows selection of the speed of the fan 106. The button 218 is preferably a press button that runs the motor 108 at least two predefined speeds. For example, the default speed of the motor 108 is speed- 1, if the user presses the button 218 then the speed-2 is selected, on further pressing the button 218 again speed- 1 is selected.

Button 214 is to be used when the system 100 is in the mode C and the LED 228 is ON. Now the user may take corrective action to improve the performance of the system 100. The preferred steps to be performed by the user include switching off the system 100. In a next step, the user unplugs the power cable. Then the water tank 116 is pulled outward, but the tank 116 still remains attached to the system 100. Then water is filled in the tank 116. The user pushes the tank to 116 the original position. The user inserts the power plug in a socket and the power is switched ON. The system 100 remembers previous mode in which the system 100 was switched off while being in mode C. Now the system 100 continues to remain in mode C. The user presses the button 214 so that the motor 108 is switched ON, the system 100 starts operating in normal condition and starts at step 400 of as shown in FIG. 4A. When the system 100 operates in accordance with the mode B, the user adds water into the water tank 116 and restarts the system 100. In the mode B the user need not to press any reset button 214-216 on the panel 117. The system 100 resumes mode B.

When the LED 230 is ON, the system 100 operates in accordance with mode E. In such a situation the user is supposed to replace the existing media 104 with another approximately identical media 104. The user opens the top cover 124 to remove and replace the media 104. After assembling the new media 104 the user presses the power ON button after which the system 100 resumes the operation in the previous mode E. Then the user presses button 216 which informs the microprocessor 114 to start the operation in the preferred mode A. When the LED 230 is blinking, the system 100 operates in mode D. Blinking of LED 230 indicates that the media 104 has started deteriorating. The user replaces the media 104 and restarts the system 100 which resumes the mode D. In the mode D, the user needs not to press any reset button 214-216 on the panel 117. When the LED 232 is ON the system 100 operates in mode F. Now the user needs to make a call to a predefined call center to fix the problem. The system 100 enters into different modes (A-F) depending upon the operating circumstances like the level of water or condition, humidification media 104 or condition of the motor 108 and the like.

Those who are skilled in the art will understand that that principal of the humidifier system 100 is to monitor a temperature and % RH of the air near inlet and temperature at outlet recorded by microcontroller 114 reflects the reduced efficiency of humidifier system 100. The humidifier system 100 of the present invention controls the process of humidification by monitoring the air temperature variations in proximity to outlet vent 126 of the system. Alternatively, process of humidification is also monitored by recording the variation of air temperature and/or a percent relative humidity (% RH) at an air outlet and / or inlet either alone or in combination.

For example, the system has a useful tank of capacity is 2 liters, water holding capacity of the media 104 is 400 ml, and the humidification rate of the system 100 is 200 ml/hour at standard conditions of 20°C DBT (Dry bulb temperature) and 30% RH (Relative humidity). The specifications and the standard conditions imply that the system 100 can run for 10 hours if the system is operated at a humidification. rate of 200 ml/hour in healthy conditions. Thereafter, the system 100 switches to the mode B and operates for approximately two hours provided that the system 100 continues to run at the humidification rate of 200 ml/hour. If the system runs further, the system 100 is switched to mode C which leads to stopping the operation of the system. During the usage of the humidifier system 100, a user needs to add water into the water tank 116 and also needs to change the humidification media 104 as per the condition of the media 104. It is also recommended to clean the water tank 116 periodically. The humidifier system 100 is designed to help the user to do all of these operations in a simpler and hygienically safe way. The water tank 116 is slidably accessible by the user for filling the water. To add the water to the tank 1 16, the user needs to pull the water tank 116 slightly outward using the handle feature provided to facilitate this operation. The user can easily add the water into the water tank 116. After adding the water to the maximum recommended level, the user just needs to push back the water tank 116 back to the original position. The humidification media 104 is advantageously removable and replaceable. To change the humidification media 104, the user needs to unlock the top cover 124 at the left end when viewed from front of the appliance. The top cover 124 is required to rotate in clockwise direction about the body to access the humidification media 104. The humidification media 104 then can be lifted by holding the hand grip and can be conveniently taken out. The new humidification media 104 is then positioned in the predefined location. The top cover 124 then can be locked back in original position.

To clean the water tank 1 16, the humidification media 104 is removed and the water tank 116 is pulled out. The water tank 116 can be cleaned, dried and then put back again in the original position. The humidification media 104 is then put back in place followed by locking the top cover 124. It is recommended to un-plug the power cord 210 from the supply mains to carry out even any one of the above operations.

The smart evaporative humidifier system 100 monitors the temperature difference (delta) of the dry air and the wet air to judge a plurality of performance parameters of the humidifier system 100. The smart cold evaporative humidifier system 100 of the present invention monitors the condition so that the humidifier system 100 is operated at the optimum level of operations. The user can see the status of the water level. Further, the user is addressed with the performance of the humidification media 104. The humidifier panel informs the user to refill water in the tank with a prior intimation. Also the user is informed about the replacement of the humidification media 104. There is a smart provision of the switching off the humidifier system 100 on expiry of the humidification media 104. The humidifier is designed to avoid running at any time with no water in the tank 1 16. Beside the water tank 116 being dry and the humidification media being dry, mode C is also able to detect, if the protective transportation packaging material on the humidification media 104 is removed before installing it into the system. Mode C is also able to detect if the humidification media is installed into the system or not. By execution of the mode F, if the motor 108 is dead or open circuit then the power drawn by the system 100 is approximately equal to the standby power. This indication is provided by switching on the LED 232. The invention can be used in cold evaporation technology or a water wash system or the dessert coolers which are most popular in hot and dry countries not limited to any demographic location.

In another embodiment, the system of the present invention has only one sensing element that monitors T _we t only. In this alternative embodiment, Tdry and inlet % RH is not monitored; however, the system 100 advantageously operates on the basis of the T _wet values only. In this embodiment, the life of the humidification media 104 or the time of replacement of the humidification media 104 is not addressed.

As shown in FIG. 6, in accordance with yet another embodiment, in a first step 600 the user starts the operation of the system 100. In a second step 602, the timer is reset to a value zero. In the next step 604, a delay of a predefined amount of time is executed, for example, 120 seconds. In the step 606, the outlet air temperature T _we t is noted which is recorded as T _wet p. In a next step 608, a second time delay is executed in the system 100 by the microprocessor 114, for example, delay of 120 seconds. In a next step 610, the temperature is noted which is termed as T _we t _C . However the T _wet /c can be T _we t _P for subsequent cycle after repeating step 608. In a next step 612, a value of M is calculated such that M= [( Twet c - T _{wet p} )/2]. In a next step 614, if M is equal to zero then the control goes to a next step 616 where the mode C is activated. In step 614, if M=0 is 'N' then the control goes to a next step 622. In step 616, Mode C is activated whereinthe LED 228 is switched on and the motor is stopped. The program stops in a step 618. The lighting LED 228 indicates that the humidification media 104 is completely dry and the tank 1 16 should be filled with water.

In the step 622, if M>X1 is Y, where XI is a predefined value, then the control goes to a next step 624 where the mode B is activated. In this embodiment XI = 0.06 which is decided. In the step, 624, the LED 228 blinks thereby indicating that the humidification media 104 is now getting dry and the level of the water in the tank 116 is now decreasing below a predefined level. After executing the step 624, the control goes back to the step 608 and the operation continues. Now in the step 622, if M>X1 is 'N' , then the control goes to a step 626 where mode A is activated after which, the control goes to the step 608 and the operation continues.

The drop in DBT of the wet / humid / moist air at the outlet of the system 100 depends upon the DBT of the dry air at the inlet of the system 100, the %RH of the dry air at the inlet of the system 100, amount of air flow through the inlet vents 128 and upon the thermal efficiency of the system 100. For example, in the this embodiment, the drop in DBT of the wet air is seen to be 7° Celsius with DBT at inlet being 30° Celsius and %RH being 50.

In the given embodiment if the DBT of the wet air drops by more than 3.5° C and assuming the , performance greater than 50% of the reference value to be the limiting value to change the humidification media, the system 100 is said to be in mode A. If the drop in DBT of the wet air is less than 3.5, then the system 100 is in mode D and further if the drop reduces to lower then 3, then the system is in mode E. If the drop in DBT of the wet air starts to reduce in succession measurement cycle, then the system 100 is in mode B.

The embodiments of the invention shown and discussed herein are merely illustrative of modes of application of the present invention. Reference to details in this discussion is not intended to limit the scope of the claims to these details, or to the figures used to illustrate the invention.