1. Field of the Invention
An energy conservation system to selectively control the temperature of water within a water storage tank based upon predicted hot water usage derived from historical data.
2. Description of the Prior Art
The amount of energy used to heat and cool most homes in the United States typically consumes a substantial portion of an annual energy budget. Hot water heating is another significant draw on the consumption of energy. Although many water heating options are available in the United States, storage water heaters are the most commonly used as such heaters are relatively easy and inexpensive to install. Energy cost for hot water production can be reduced by insulating hot water pipes leading from a water heater tank to plumbing fixtures and appliances in the home, providing an insulating jacket around a water heater's tank, lowering the water temperature maintained in a storage hot water heater's tank, and selectively reducing the amount of hot water used in the home for laundry, baths, showers, dishwashing, and other routine tasks. However, since the steps of lowering the pre-set temperature on a water heater thermostat and providing insulation each only contributes a maximum annual energy savings of approximately 5%, other means of energy savings are still needed. Another option for heating hot water is a tankless water heater. However, such systems have several disadvantages including limited flow rates and the potential need for special wiring. Moreover, people's usage patterns or habits routinely vary.
Also, these systems achieve the best energy savings when employed in homes having floor plans purposefully locating hot water faucets and appliances using hot water in consolidated locations so as to minimize the amount of plumbing conduit required, and where high efficiency fixtures are also used. Thus, with current limitations, water heating systems are not capable of providing the widespread residential energy reduction currently desired and needed for heating hot water in residential applications in the United States. Additional options for hot water generation in residential applications include heat pumps, as well as solar, integrated, and indirect systems. Even though some of these alternative systems have a lower operating cost than water heating systems, most have a higher installation cost. Other disadvantages of such alternative systems include limited suppliers and equipment availability, the need in indirect and integrated systems for heat exchanger installation, the need in solar systems for ample non-shaded roof space or other open area that receives a calculated minimum number of hours of solar radiation each day, and the difficulty in finding experienced installers.
In contrast, the present invention modifies the operation of the water heater by providing an automated system that learns to adjust current hot water availability from established patterns of hot water use. Energy savings through use of the present invention can be approximately 20% to 50% over that provided by a conventional water heater operated by a timer allowing the present invention system to typically recoup cost and installation expense in less than one year. No other known devices used for control of water heater activity so as to maintain a readily available supply of hot water for use upon demand, function in the same manner as the present invention or provide all of its features and advantages.
The present invention relates to an energy conservation system to control the operation of a water heater operable in an automated mode to provide hot water from a water storage tank preheated to one of a plurality of temperatures or temperature ranges corresponding to a plurality to demands for different quantities of hot water. The energy conservation system derives a plurality usage demands for different quantities of hot water for a usage cycle or cycles such as a week or plurality of weeks based upon a statistical usage model of hot water demands with respect to time, duration and day and quantity.
The energy conservative system comprises a system display and control enclosure to house a control and display system in combination with a water heater including a water storage tank having an inlet pipe and an outlet pipe in fluid communication with the interior of the water storage tank, at least one heat element and a thermostat. A water temperature sensor is disposed in heat transfer relationship relative to the inlet pipe or the outlet pipe to sense the cold water temperature or hot water temperature respectively and to generate and transmit a signal corresponding to the cold water temperature or the hot water temperature to a microprocessor.
The control and display system comprises a microprocessor having logic and circuitry to control the operation of the various components of the present invention including an LED module, a power supply module, a detection module and an LCD module each coupled or interconnected to the microprocessor.
The microprocessor includes a microcontroller, a clock and a memory. The microcontroller performs the logical sequence to operate the input and output circuitry and the various devices including the LED module, the power supply module, the detection module and the LCD module.
The energy conservation system measures flow events from the water storage tank with respect to time, day and duration to derive demand for hot water and predict future usage patterns taking into account for variations in time of usage from the actual demands due to habits of the user(s) schedule.
Flow events or periods are sensed and recorded by the energy conservation system. For example, a decrease in the temperature of the inlet pipe or cold water line of a predetermined amount indicates the start of flow of hot water from the water storage tank and the increase of the temperature of the inlet pipe or cold water line indicates a cession of the flow of hot water from the water storage tank. If the elapsed period of the flow is more than a predetermined period of time, the microprocessor records a demand for a predetermined maximum quantity for hot water demand or event. When the period or duration between the as the start of another flow of hot water from the water storage tank and the cession of the flow of hot water from the water storage tank is less than a predetermined period of time, the microprocessor records a predetermined minimum quantity for hot water demand or event. Of course, changes in temperature on the outlet pipe or hot water line could also be used to sense, measure and record demands for hot water.
When there is no flow of hot water through the water storage tank the temperatures sensed at the inlet pipe and outlet pipe of the water storage tank are substantially the same or equal to each other. Flow of hot water from the water storage tank may be detected or determined by comparing the temperatures of the inlet water sensed by the inlet water sensor and the outlet water by an outlet water sensor in the microprocessor and generating a flow signal when the difference between the inlet water temperature and the outlet water temperature is a predetermined amount. When the temperature difference between the inlet water and the outlet water decreased to a predetermined amount then the flow signal ceases.
The microprocessor includes means to record incrementally when the flow of water from the water storage tank starts or commences and stops or ceases to measure or detect the demand for a first quantity of hot water for a first period of time and to measure or detect the demand for the second quantity of hot water for a second period of time.
The time at which the heating element must be energized to meet the predicted hot water demand is determined by the water energized to meet the predicted hot water demand is determined by the water heater characteristics and quantity of demand for hot water adjusted for variations of actual hot water usage.
The daily time demands for hot water are recorded for a predetermined number of weekly cycles and averaged. The average peak time for the recorded demands are set back along the curve to establish a first time period set back margin from the average peak time. A second set back margin of a fixed period of time is used to offset the heating cycle prior to the predicted demand for hot water.
The energy conservation system maintains the water storage tank at a minimum temperature. The water within the water storage tank is heated by commencing to elevate the temperature to reach a first predetermined temperature or a first predetermined range to supply a first predetermined quantity of hot water at the predetermined time of day on a given day of the week or heating the water within the water storage tank to a second predetermined temperature for a second predetermined temperature range to supply a second predetermined minimum quantity of hot water at a predetermined time of day on any given day of the week derived from the duration or period of time that a hot water demand occurs comprising a plurality of cycles such as ten (10) weeks calculated to set back for a margin for habit variations.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
For a fuller understanding of the nature and object of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
Similar reference characters refer to similar parts throughout the several views of the drawings.
The present invention relates to an energy conservation system to control the operation of a water heater operable in an automated mode to provide hot water from a water storage tank preheated to one of a plurality of temperatures or temperature ranges corresponding to a plurality of demands for different quantities of hot water. The energy conservation system derives a plurality usage demands for different quantities of hot water during a learning period over a usage cycle or cycles such as a week or plurality of weeks based upon a statistical usage model of hot water demands or usage with respect to time and day.
The mechanical aspects of the energy conservation system are best understood with references to
The most preferred embodiment of the present invention provides an energy-saving automated system 2 used for the activation of a hot water heater that at a minimum needs a small amount of data entry by its manufacturer, seller, installer, and/or user prior to activation, whereafter it provides a semi-artificial intelligence that learns to adjust current hot water availability from previously established patterns of hot water use to provide a readily available supply of hot water, for use upon demand, with significant energy savings. The data entry could be as simple as the entry of a zip code or a global positioning satellite (GPS) designation, which would provide the present invention system with general climate and seasonal information, so that energy consumption can be significantly reduced during the entire year, and not just a portion of it. However, for even better energy savings and/or when the user has at least a minimal amount of technical aptitude, the present invention system could be configured so that the amount of data entry provided by the user is more extensive, introduced at any time, and includes but is not limited to an automatic and/or manual over-ride capability for anticipated periods of heavy hot water use, automatic or manual accommodation for daylight savings time, automatic and/or manual accommodation for seasonal temperature changes, and automatic and/or manual accommodation for the ambient temperature of its installation site, manual accommodation for anticipated holiday activity, and/or regular days off of work where it is anticipated for hot water usage patterns to be distinct. The present invention system would also comprise precautions against false activation to maximize energy saving, such as establishing a minimum period of faucet on-time before any pattern modification is made. Applications include, but are not limited to, residential use and other situations where some predictability as to the time and duration of hot water use can be established.
To accomplish energy savings, the present invention at a minimum would comprise two temperature sensors 66, one that identifies the temperature of the water entering its associated hot water tank 72, and the other identifying the temperature of the water leaving hot water tank 72. As an option, the present invention could also include a flow meter or water level sensor 76. It is considered to be within the scope of the present invention for the internal clock used to account for pre-determined time period, such as a week or a month. However, a vacation mode would not be required, although it could be provided as an option, since the present invention system would shut down hot water production when it senses a lack of hot water usage during periods where demand had previously been present. Although a different time period could be used as a precaution against false activation, in a home having three to four residents, two bathrooms, a kitchen sink, a dishwasher, a washing machine, and a laundry tub, and depending upon its floor plan and whether plumbing fixtures and appliances using hot water are consolidated or not, it is preferred for a time period between approximately fifteen seconds and approximately sixty seconds to be used before any modification to usage patterns is made. It is expected that energy savings provided by the present invention to be approximately 20% to 50% greater than that achievable by demand hot water heating system controlled by a timer. Thus, use of the present invention system will rapidly recoup its cost and installation expense and in most U.S. homes is expected to pay for itself in less than one year.
Use of the present invention for saving energy in hot water heater tank 72 operation involves the use of various distinct modes including a mode that records patterns of hot water usage and then creates on a moving average of historical data to predict hot water demand.
The operation of the energy conservation system is best understood with reference to
The system display and control enclosure 200 includes a front display panel 226 comprising an LED window 228 to display the LEDs, an LCD window 230 to display the LCDs and a plurality of system control buttons or keys generally indicated as 232.
Together,
Together,
Together,
The energy conservation system measures flow events from the water storage tank 206 with respect to time, day and duration to derive demand for hot water and predict future usage patterns taking into account for variations in time of usage from the actual demands due to habits of the user(s) schedule.
The closer the inlet water sensor 220 and the outlet water sensor 222 is located to the inlet port 210 and outlet port 212 respectively the more accurate the correspondence of the sensed temperature to the temperature of the water storage tank 204. Moreover, and temperature differences due to the placement of the inlet water sensor 220 and the outlet water sensor 222 may be calculated or measured allowing for appropriate correction or adjustment by the microprocessor 102.
Flow events or periods are illustrated in
In other words, when there is no flow of hot water through the water storage tank 204 the temperatures sensed at the inlet pipe 206 and outlet pipe 208 of the water storage tank 204 are substantially the same or equal to each other. Flow of hot water from the water storage tank 204 is detected or determined by comparing the temperatures of the inlet water sensed by the inlet water sensor 220 and the outlet water by an outlet water sensor 222 in the microprocessor 106 and generating a flow signal when the difference between the inlet water temperature and the outlet water temperature is a predetermined amount such as substantially equal to or greater than about 2.5° F. When the temperature difference between the inlet water and the outlet water decreased to a predetermined amount such as substantially about 1° F. or less than the flow signal ceases.
The microprocessor 102 includes means to record incrementally when the flow of water from the water storage tank 204 starts or commences and stops or ceases incrementally defined by a first table or set of equal time periods such as 15 seconds to measure or detect the demand for the first quantity of hot water a first period of time such as about two (2) minutes or greater and a second table or set of equal time period such as 5 seconds to measurer or detect the demand for the second quantity of hot water as a second period of time such as between about thirty (30) seconds and about two (2) minutes.
A demand for hot water less than a predetermined time period such as about thirty (30) seconds is not recorded as a demand for hot water.
The time at which the heating elements 214 and 216 must be energized to meet the predicted hot water demand is determined by the water heater characteristics and quantity of demand for hot water adjusted for variations of actual hot water usage.
The daily time demands for hot water are recorded for a predetermined number of weekly cycles such as ten (10) weeks and averaged as shown in
The energy conservation system which maintains the water storage tank at a minimum temperature such as 85° F. is capable of heating the water within the water storage tank to a first predetermined temperature such as 114° F. or a first predetermined range such as from 100° to 114° F. to supply a first predetermined minimum quantity of hot water at a predetermined time of day on a given day of the week or heating the water within the water storage tank to a second predetermined temperature such as 85° F. or a second predetermined temperature range such as from 85° F. to 100° F. to supply a second predetermined minimum quantity of hot water at a predetermined time of day on any given day of the week derived from the duration or period of time that a hot water demand occurs during a learning period comprising a plurality of cycles such as ten (10) weeks. The demand for the first predetermined minimum quantity of hot water and for the second determined minimum quantity of hot water is measured or defined as substantially two (2) minutes or more of water flow from the water storage tank and between substantially thirty (30) seconds and substantially two (2) minutes of water flow from the water storage tank 204 respectively. The maximum temperature such as 114° F. will always be set below the thermostat so that the microprocessor 102 will have full control of the water temperature.
The microprocessor 102 includes logic to determine and set the minimum operating temperatures set point for the water heater 202 as a function of the inlet or cold water temperature fed into the water storage tank 204. For example, the inlet water temperature may range from an average of 37° F. in northern climates to an average of 72° F. in southern climates. Thus, to account for the variation in regions as well as variations throughout the year in a locale subject to significant seasonal temperature swings, the microprocessor 102 increases the minimum set point as the inlet water temperature decreases to meet the increased need or demand for energy to heat and maintain the water temperature with the water storage tank 204. The microprocessor 102 may include logic to compensate for variations of ambient air in the water temperature.
Power usage is measured by the current or amperage sensor 22 (
The energy conservation system may operate in an override mode to de-energize the heating elements 214 and 216 by selecting the override mode through the use of the buttons or keys 232 to avoid any use of power or energy such as during an extended absence while on vacation (
In addition, the energy conservation system may operate in a standard mode selected by the buttons or keys 232 wherein the water with the water storage tank 204 is maintained at a fixed temperature set point without response to usage or demand (
Finally, a user can program the energy conservation system to operate under a one of a plurality of selected time and day regime by buttons or keys 232 (
It will thus be seen that the objects set forth above, among those made apparent from the preceding description are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
Now that the invention has been described,
Number | Name | Date | Kind |
---|---|---|---|
6795644 | Bradenbaugh | Sep 2004 | B2 |
7380522 | Krell et al. | Jun 2008 | B2 |
7380523 | Donnelly | Jun 2008 | B2 |