1. Field of the Invention
This application relates generally to evaporative coolers and more particularly to an evaporative cooler paired to a programmable controller system which is coupled to a wireless remote sensor unit which collects outside environmental data.
2. Brief Description of the Prior Art
Wireless transmission of data, and specifically environmental data such as temperature and humidity, has seen much in the way of prior art. The main use of this data has been in weather recording and reporting. An example of this prior art is U.S. Pat. No. 6,597,990, which discloses a weather detector and alarm. This use of prior art only reports and displays the transmitted data, whereas this invention also uses the data for process control. Evaporative coolers, also known as swamp coolers are best suited to dry desert climates like that found in the southwestern United States. Evaporative coolers (
There are two significant problems with the prior art of evaporative coolers. The first is their high water usage, and the second is inability to respond to changing environmental conditions, creating a condition of high humidity inside the building being cooled.
Prior art evaporative coolers of the type commercially available are generally controlled by a simple rotary six position switch (
There have been a number of attempts in the prior art to solve the problem of controlling evaporative cooler through the use of thermostats. Exemplary of the prior art are U.S. Pat. Nos. 4,232,531, 4,580,403, 4,673,028, and 4,4775,100. While providing an improvement over manual control, the use of line voltage thermostats have their own drawbacks. U.S. Pat. No. 4,4775,100 discloses a wide range of plus or minus 20 degrees Fahrenheit to prevent rapid cycling of the evaporative cooler, which allows hot outside air to enter the building. Since simple thermostat control turns on the water pump and blower fan at the same time, this will blow hot outside air into the building until the pads are properly wet. U.S. Pat. No. 5,031,412 has solved some of these problems by incorporating into a digital electronic controller, a thermostat and a real time clock. The clock allows for a cycle of pre-wetting the pads before starting the blower, and for starting and stopping the evaporative cooler at specific times of the day, such as morning or evening when outside temperatures are cooler. It is still unable to adapt to changing environmental conditions and may cause high interior humidity levels leading to personal discomfort, and possibly building damage, if left uncorrected.
In accordance with the present invention, the above and other problems are solved by the use of a microprocessor based logic system, with temperature and humidity sensors in the evaporative cooler controller, and the addition of an outside sensor that wirelessly reports external temperature, humidity and barometric pressure back to the controller. The addition of the microprocessor and the extra sensors allows better control of the interior temperature and humidity by responding to changing environmental conditions both inside and outside.
For example, a typical problem associated with evaporative coolers is that when left operating unattended and the outside humidity increases, such as during a rain shower, the interior humidity can increase to the point of condensation, causing damage with repeated occurrences. This problem is solved by comparing the interior and exterior temperature and humidity using sensors. The end user is able to adjust the interior and exterior temperature and humidity settings to their comfort level and the microprocessor will compare them to current readings. If the outside humidity level increases above the set level, such as during a rain shower, the water pump will be automatically shut off but rain cooled air will continue to be circulated. If the interior humidity goes above the pre-set level, the water pump will again be shut off and drier air is circulated. Another example is that in the regions where evaporative coolers are most useful, there is usually a large difference in temperature between daytime and nighttime. The night air is much cooler and usually does not need additional cooling. The external temperature sensor measures this value and the controller will again turn off the water pump and continue to circulate the cooler air inside the building.
The addition of a real time clock and adjustable start and stop timers allows for further control such as when the building is unoccupied. The real time clock is augmented with a receiver to use NIST radio transmitted time signals or GPS signals to set the time, with the user only setting the time zone, which would be maintained in the EEprom memory. Usually after a cool night, a building will retain its cooler temperature for a few hours. The start and stop timers allow the cooling system to be shut down until shortly before the building is expected to be occupied, and then automatically start to cool the building to a comfortable temperature.
Another advantage is the microprocessor logic control of the fan speed. If for example the actual temperature is more than five degrees above the user set temperature, the automatic control will enable the fan on the high speed. When for example the difference between the actual temperature and the user set temperature decreases below five degrees the fan will be automatically switched to a lower speed.
Microprocessor control of the pre-wet feature for wetting the cooling pads allows the system to use this feature only when necessary such as when starting the system or restarting the water pump after an automatic shutdown. It is not necessary when switching between fan modes.
The end user has programmable control of the interior and exterior temperature and humidity settings and the start and stop times, including separate start and stop times for weekdays and weekends. Additionally, there are full manual controls that provide access to all the manual settings normally found on the industry standard six position control switch.
In accordance with other aspects, the present invention relates to a system for controlling the output of an evaporative cooler in such a manner as to regulate the interior temperature and humidity of a building, in response to changing environmental conditions inside and outside of the building.
The great utility of the invention is that by limiting operating time of the evaporative cooler to when it is actually needed, there is significant savings in water use and electricity costs, as well as an increase in personal comfort. This is all accomplished without the need for any additional building wiring, than what would be necessary for a evaporative cooler wired with the prior art standard six position switch.
These and various other features as well as advantages, which characterize the present invention, will be apparent from a reading of the following detailed description and a review of the associated drawings.
The accompanying drawings, which are incorporated in and constitute a part of the specifications, illustrate an embodiment of the invention and, together with the description serve to explain the principles of the invention.
Preferred embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. Referring now to
The evaporative cooler controller of the present invention includes the main controller, with front panel illustrated in
The a main controller unit, is used inside a building, to control the inside temperature and inside humidity by operating and controlling a paired evaporative cooler, said main controller unit is programmable in response to the input data received which are: the outside measured humidity, outside measured temperature and outside barometric pressure, and said main controller unit is programmable according to a plurality of programming modes to generate digital control data to be sent to a paired evaporative cooler to cause the control of variations of the paired evaporative cooler fan's speed and the variations of the paired evaporative cooler water pump speed.
The main controller microprocessor programmable by the user is a eight core parallel microprocessor designed to:
The front panel of the controller 300 in
The EEprom memory is used to store user settings to avoid their loss in case of a power interruption to the main controller unit. The unique serial number ID is electronically inserted into all Radio Frequency (RF) communications with the remote sensor unit to electronically receive data only from a paired remote sensor unit. The EEprom memory also stores a user-entered time zone offset for National Institute of Standards and Technology (NIST) radio-transmitted time signals or GPS signals.
The front panel of the main controller unit comprises manual switches which are:
The front panel of the main controller unit also has manual buttons which are:
The battery cover 310 holds a backup battery which, in the event of a main controller unit power loss, will maintain time and date data stored inside a real time clock;
The multi-line digital backlit liquid crystal display (LCD) display unit 301 displays the main controller's programming data. After start up, the microprocessor will continually cycle through a series of information and status displays on the LCD 301. The information displayed consist of current interior and exterior temperature and humidity, current exterior barometric pressure and pressure history, complete date and time, interior temperature and humidity settings, weekday and weekend timer status, and timer activity status.
The front panel allows a user to further program a connected evaporative cooler by entering the following setting data: a desired inside temperature, an upper limit inside humidity, an upper limit outside humidity. Additionally, a unique serial ID number can be entered by a user on the main controller front panel and stored inside a EEprom memory with other user settings, to allow a replacement of a remote sensor, if necessary.
There are two major modes of operation: AUTO and MANUAL. AUTO mode allows the microprocessor full control based on the user selected settings. MANUAL mode requires the user to manually select the fan and water pump settings. While in MANUAL mode the LCD 301 will continue to cycle through the information displays, but the microprocessor will not be able to control the relays that switch the A/C power to the pump and blower fan of the evaporative cooler. This will be controlled by the FAN 308 and PUMP 309 switches. For manual operation, the MANUAL/AUTO switch 306 should be set to MANUAL, the PUMP switch 309 set to ON, and the FAN switch 308 set to either LOW or HIGH.
These settings allow for full control of the evaporative cooler, without a pre-wet function. Manual shutdown for winter or maintenance is accomplished by setting the MANUAL/AUTO switch 306 to MANUAL, the PUMP switch 309 set to OFF, and the FAN switch 308 set to OFF.
With the MANUAL/AUTO switch 306 in the AUTO position, the microprocessor completes functions based on the logic in the operating program and the settings input by the user. The user settings are changed from the default settings by placing the PRGM/RUN 307 switch in the PRGM position, this will cause a programming menu to be displayed and illuminated on the LCD 301. The menu selections are changed by using the UP 303 and DOWN 304 buttons to select the correct numerals, and using the NEXT 305 button to step through the functions. The menu selections are: Inside Temp (Desired inside temperature) Setpoint, Inside Rh (Upper limit inside humidity) Setpoint, Outside Rh (Upper limit outside humidity) Setpoint, Set Date (Current date mm:dd:yy:dow), Set Time (Current time A/P: hh:mm), Set Wkdy (Weekday start of operation) Start (hh:mm), Set Wkdy (weekday) Stop (hh:mm), Weekday Timer On/Off, Set Wknd (weekend) Start (hh:mm), Set Wknd (Set weekend start day and time) Stop (hh:mm), and Weekend Timer On/Off and Set weekend end day and time. At the end of the menu the user receives a prompt to set the PRGM/RUN 307 switch back to the RUN position.
At the end of the programming sequence, the microprocessor automatically saves the chosen Current date and Current Time to the real time clock, the remaining data is saved to a EEprom Memory for storage and to RAM (random access memory) for program working functions. The illumination of the LCD 301 is turned off, and the information and status displays on the LCD 301 resume cycling. Pressing the NEXT 305 button while this data is being displayed will cause the LCD 301 to be illuminated for five seconds. Should it become necessary, momentarily holding down the RESET 302 button will cause the microprocessor to re-start and clear any malfunction. While the microprocessor is being re-started or in the event of a power loss, a back up battery, under the battery cover 310, will maintain the time and date data stored in the real time clock.
The front panel comprises:
The hand held remote control device allows the user to further program a connected evaporative cooler by entering the following setting data: a desired inside temperature, an upper limit inside humidity, an upper limit outside humidity;
Referring to
User settings are saved in the EEprom memory, so that user settings do not have to be re-entered if power to the controller is lost.
Setting of the real time clock is accomplished by holding down the UP button 403 for two seconds to enter the programming mode. Once in the programming mode, the LCD 401 illuminates and displays a menu for setting the month, day, year, and day of the week. These are set using the UP 403 and DOWN 404 buttons to increment or decrement the displayed setting by one unit, and using the NEXT 405 button to step through the functions and illuminate the LCD display for five seconds. After setting the day and date, another menu for setting the time is automatically displayed. Setting of the time is accomplished in the same manner. At the end of the programming sequence, the microprocessor automatically saves the chosen date and time to the real time clock, turns off the illumination of the LCD 401, and resumes alternating the temperature and humidity data with the date and time in the display. Pressing the NEXT button while this data is being displayed will cause the LCD 401 to be illuminated for five seconds. Should it become necessary, momentarily holding down the RESET 402 button will cause the microprocessor to re-start and clear any eventual malfunction. While the microprocessor is being re-started or in the event of a power loss, a back up battery, under the battery cover 406, will maintain the time and date data stored in the real time clock.
The battery cover 406 will hold a backup battery which, in the event of a power loss, will maintain time and date data stored inside a real time clock;
The remote sensor microprocessor, programmable by a user, is an eight-core parallel microprocessor designed to maintain a real time clock, command the outside temperature humidity and barometric pressure sensors to collect outside temperature, outside humidity and weather forecast data to be transmitted wirelessly to the main controller micro-processor for processing.
Referring to
The remote sensor microprocessor, programmable by a user is designed to:
Pre_wet_done is an internal program flag that can be set to zero or one, where zero indicates that the pre-wet sequence will be executed the next time the program logic is executed; the value of one indicates that the pre-wet sequence has been executed and the sequence needs not to be executed the next time the program logic is executed.
Step 1001 covers gathering the data for comparison from the interior sensors in the controller and the exterior sensors in the remote sensor. Step 1002 looks at the flag for the pre-wet sequence, for wetting the pads before the fan is started. If the flag is set, that indicates that the pre-wet sequence, step 1003, has been run and the program can skip steps 1004 through 1007 and go to step 1008. Steps 1004, 1006, 1008, and 1010 are almost identical; all are looking at the data for a combination of factors. They are checking if the inside temperature is greater than the temperature set point, the outside temperature is greater than the temperature set point, the interior humidity is less than the interior humidity set point, the exterior humidity is less than the exterior humidity set point, and whether the pre-wet sequence has been run or not. Steps 1004 and 1008 are checking if the inside temperature is greater than the temperature set point by more than 5 degrees. Steps 1006 and 1010 are checking if the inside temperature is greater than the temperature set point minus 2 degrees. A yes response on either step 1004 or 1006 will cause the pre-wet sequence to be run, steps 1005 and 1007 respectively, which turns on the pump only for 4 minutes, sets the flag to 1, and the program goes around the logic sequence again. With the pre-wet flag set to 1 this allows the rest of the options to come into play.
Step 1008 checks if the inside temperature is greater than the interior temperature set point plus 5 degrees, and the outside temperature is greater than the interior temperature set point plus 1 degree, and the interior humidity is less than the interior humidity set point, and the exterior humidity is less than the exterior humidity set point, and whether the pre-wet sequence has been run or not. A yes decision on step 1008 will turn on the pump and activate the fan on high speed, step 1009.
Step 1010 checks if the inside temperature is greater than the interior temperature set point minus 2 degrees, and the outside temperature is greater than the interior temperature set point plus 1 degree, and the interior humidity is less than the interior humidity set point, and the exterior humidity is less than the exterior humidity set point, and whether the pre-wet sequence has been run or not. A yes decision on step 1010 will turn on the pump and activate the fan on low speed, step 1011.
Step 1012 checks if the inside temperature is greater than the interior temperature set point plus 5 degrees, and the outside temperature is less than the interior temperature set point, or the interior humidity is greater than the interior humidity set point, or the exterior humidity is greater than the exterior humidity set point. A yes decision on step 1012 will turn off the pump, activate the fan on high speed, and set the pre-wet flag to 0, step 1013.
Step 1014 checks if the inside temperature is greater than the interior temperature set point minus 2 degrees, and the outside temperature is less than the interior temperature set point, or the interior humidity is greater than the interior humidity set point, or the exterior humidity is greater than the exterior humidity set point. A yes decision on step 1014 will turn off the pump, activate the fan on low speed, and set the pre-wet flag to 0, step 1015.
Step 1016 checks if the inside temperature is less than the interior temperature set point minus 2 degrees. A yes decision on step 1016 will turn off both the pump and the fan, and set the pre-wet flag to 0, step 1017.
More concisely, the main controller microprocessor executes:
The pre-wet sequence, is commanded and controlled by the main controller unit logic of the microprocessor, and it is executed before the cooler's fan is started for the first time after a time of inactivity, consists in running the cooler's water pump for four minutes to wet the cooling pads which are mounted in front of the cooler's fan inside the controlled evaporative cooler.
Due to the multi-core nature of the chosen microprocessor, this logic tree is continually cycling in parallel with the data collection from the remote sensor and the local sensor on the controller. The data display and real time clock and timer functions are also being maintained in parallel by other processing cores in the microprocessor.
The second embodiment of the invention consists in a main controller divided into two separate units. The primary controller indoor sensors and all control logic resides inside a hand held remote control, coupled to a separate, RF operated, switching unit which is installed inside the cooler to be controlled and operated.
At the top is the view from the back showing the plugs for the fan 1101 and the pump 1102. These would be inserted into the existing sockets in the evaporative cooler, using the existing plugs for the pump and fan motor and require no extra wiring. At the bottom is the front view showing the replacement sockets for the fan 1104 and the pump 1103. In the center is a top view showing the relative positioning of the sockets and plugs. This unit is situated inside the evaporative cooler between the existing plugs and sockets. Use of this unit would require bypassing any prior art control switch to provide unswitched power to the existing sockets so the unit can control the switching of power for the fan and pump.
The switching unit will comprise a housing equipped with a switching unit comprising a housing, a radio frequency transceiver to receive wirelessly operating commands from said hand held remote control device, a hand-held controller unit microprocessor programmable by a user to process commands from said hand held remote control unit to digitally control the operation and speed of a paired evaporative cooler's water pump and electric fan.
The housing is equipped with an input power plug to be electrically connected to an existing power plug inside an evaporative cooler to be controlled, that currently supplies uncontrolled electric power to the evaporative cooler's electric fan; an input power plug to be electrically connected to an existing power plug, inside an evaporative cooler to be controlled, that currently supplies uncontrolled electric power to the evaporative cooler's electric water pump; an output power plug to be electrically connected to the evaporative cooler's electric fan; an output power plug to be electrically connected to the evaporative cooler's electric water pump;
The logical operations of the various embodiments of the present invention are implemented as a sequence of computer implemented acts or program modules running on a computing system and/or as interconnected machine logic circuits or circuit modules within the computing system. The implementation is a matter of choice dependent on the performance requirements of the computing system implementing the invention. Accordingly, the logical operations making up the embodiments of the present invention described herein are referred to variously as operations, structural devices, acts or modules. It will be recognized by one skilled in the art that these operations, structural devices, acts and modules may be implemented in software, in firmware, in special purpose digital logic, and any combination thereof without deviating from the spirit and scope of the present invention as recited within the claims attached hereto.
Those skilled in the art will readily recognize various modifications and changes that may be made to the present invention without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present invention. The various embodiments described above are provided by way of illustration only and should not be construed to limit the invention which is set forth in the following claims.