Weather forecast and prediction based temperature control

Abstract

A weather forecast-based fluid heating control system having at least one hot fluid delivery point, the control system including a controller adapted to control a fluid supply to a setpoint temperature, a means for obtaining the forecasted air temperature at a future time of the location of the control system and a means for obtaining the current air temperature at a current time of the location of the control system. The setpoint temperature of the fluid supply is adjusted by an adjustment amount if the difference between the forecasted air temperature of the location of the control system and the current temperature at the current time of the location of the control system exceeds a pre-determined threshold.

Claims

1. A domestic water heating control system having at least one hot fluid delivery point disposed at a location, said domestic water heating control system comprising: (a) a controller adapted to control said domestic water heating control system to a setpoint temperature of the at least one hot fluid delivery point; (b) a means for obtaining a forecasted outdoor air temperature at a future time at the location of said domestic water heating control system; and (c) a means for obtaining a current outdoor air temperature at a current time at the location of said domestic water heating control system, whereby the setpoint temperature of said at least one hot fluid delivery point is configured to be adjusted by an adjustment amount if the difference between the forecasted outdoor air temperature at the future time at the location of said domestic water heating control system and the current outdoor air temperature at the current time at the location of said domestic water heating control system exceeds a pre-determined threshold.

2. The domestic water heating control system of claim 1, wherein said pre-determined threshold is a value selected from the group consisting of about 2 degrees F. and about 5 degrees F.

3. The domestic water heating control system of claim 1, wherein the difference between said future time and the current time is about one hour.

4. The domestic water heating control system of claim 1, wherein said adjustment amount is a value selected from the group consisting of about 1 degree F. and 2 degrees F.

5. The domestic water heating control system of claim 1, further comprising a means for obtaining a forecasted wind chill factor at a future time at the location of said domestic water heating control system and a means for obtaining a current wind chill factor at a current time at the location of said domestic water heating control system, wherein a difference of said forecasted wind chill factor and said current wind chill factor is configured to be applied to the adjustment of the setpoint temperature of said at least one hot fluid delivery point.

6. The domestic water heating control system of claim 1, further comprising a means for obtaining a forecasted heat index at a future time at the location of said domestic water heating control system and a means for obtaining a current heat index at a current time at the location of said domestic water heating control system, wherein a difference of said forecasted heat index and said current heat index is configured to be applied to the adjustment of the setpoint temperature of said at least one hot fluid delivery point.

7. A domestic water heating control system having at least one hot fluid delivery point disposed at a location, comprising: (a) a controller adapted to control said domestic water heating control system to a setpoint temperature of the at least one hot fluid delivery point; (b) a means for obtaining and comparing forecasted outdoor air temperature at a future time at the location of said domestic water heating control system and a current outdoor air temperature at a current time at the location of said domestic water heating control system to result in a first difference; (c) a means for obtaining and comparing a forecasted wind chill factor at a future time at the location of said domestic water heating control system and a current wind chill factor at a current time at the location of said domestic water heating control system to result in a second difference; and (d) a means for obtaining and comparing a forecasted heat index at a future time at the location of said domestic water heating control system and a current heat index at a current time at the location of said domestic water heating control system to result in a third difference, wherein a sum of said first difference, said second difference and said third difference is configured to be calculated and whereby, if said sum exceeds a pre-determined threshold, the setpoint temperature of said at least one hot fluid delivery point is configured to be adjusted by an adjustment amount.

8. The domestic water heating control system of claim 7, wherein each of said first, second and third difference is configured to be weighted.

9. The domestic water heating control system of claim 7, wherein said pre-determined threshold is a value selected from the group consisting of about 2 degrees F. and about 5 degrees F.

10. The domestic water heating control system of claim 7, wherein the difference between said future time and said current time is about one hour.

11. The domestic water heating control system of claim 7, wherein said adjustment amount is a value selected from the group consisting of about 1 degree F. and 2 degrees F.

12. A heating control method of a domestic water heating system disposed at a location, said method comprising a step of comparing a forecasted outdoor air temperature at a future time at the location and a current outdoor air temperature at a current time at the location, whereby if the difference between the forecasted outdoor air temperature at the future time at the location and the current outdoor air temperature at the current time at the location exceeds a pre-determined threshold, the setpoint temperature of the domestic water heating system is configured to be adjusted by an adjustment amount.

13. The heating control method of claim 12, further comprising a step of comparing a forecasted wind chill factor at a future time at the location and a current wind chill factor at a current time at the location, wherein the difference between said forecasted wind chill factor at a future time at the location and said current wind chill factor at a current time at the location is configured to be applied to the adjustment of the setpoint temperature of the domestic water heating system.

14. The heating control method of claim 13, wherein the difference between said forecasted wind chill factor at a future time at the location and said current wind chill factor at a current time at the location is configured to be weighted.

15. The heating control method of claim 12, further comprising a step of comparing a forecasted heat index at a future time at the location and a current heat index at a current time at the location, wherein the difference between said forecasted heat index at a future time at the location and said current heat index at a current time at the location is configured to be applied to the adjustment of the setpoint temperature of the domestic water heating system.

16. The heating control method of claim 15, wherein the difference between said forecasted heat index at a future time at the location and said current heat index at a current time at the location is configured to be weighted.

17. The heating control method of claim 12, wherein said pre-determined threshold is a value selected from the group consisting of about 2 degrees F. and about 5 degrees F.

18. The heating control method of claim 12, wherein the difference between said future time and the current time is about one hour.

19. The heating control method of claim 12, wherein said adjustment amount is a value selected from the group consisting of about 1 degree F. and 2 degrees F.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order that the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

(2) FIG. 1 is a diagram depicting a means by which the present weather forecast based control scheme is effected.

(3) FIG. 2 is a diagram depicting a system enabling the present weather forecast based control scheme.

(4) FIG. 3 is a diagram depicting one example in which the setpoint temperature of a water heater is set based on forecasted temperature.

PARTS LIST

(5) 2step of determining forecasted weather data 4step of comparing forecast temperature and current temperature 6controller 8zip code input 10setpoint temperature input 12heating temperature input 14heating element 16outdoor ambient temperature sensor 18internet 20weather forecast data

PARTICULAR ADVANTAGES OF THE INVENTION

(6) The present water heating control system automatically adjusts its setpoint temperature to suit the outdoor environment in which the water heating control system operates in, removing the need for a user who is already accustomed to the temperature settings of the delivery points of the water heating system to make adjustments to suit the user's needs.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

(7) The term about is used herein to mean approximately, roughly, around, or in the region of. When the term about is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term about is used herein to modify a numerical value above and below the stated value by a variance of 20 percent up or down (higher or lower).

(8) FIG. 1 is a diagram depicting a means by which the present weather forecast based control scheme is effected. There is provided a weather forecast-based water heating control system having at least one hot water delivery point, including a controller adapted to control a water supply to a setpoint temperature, a means for obtaining the forecasted air temperature at a future time at the location of the weather forecast based water heating control system and a means for obtaining the air temperature at a current time at the location of the weather forecast based water heating control system. The setpoint temperature of the water heater is adjusted by an adjustment amount if, when the forecasted air temperature at the location of the weather forecast based water heating control system is compared to the current air temperature at the location of the weather forecast based water heating control system as shown in step 4, the difference between exceeds a pre-determined threshold. Weather forecast data including such parameters as temperature, wind speed, cloud cover, wind chill factor, heat index, etc. can be made available from many sources for every location or zip code and updated hourly or sooner in many weather forecast services and communicated to the present control system via several means including, but not limited to, the internet, etc. In one embodiment, the difference between the future time and the current time is about an hour.

(9) In determining the weather forecast data to retrieve as shown in step 2, a location of the water heating system must be determined. The zip code of the location of the water heating system may be manually entered into the water heater controller. Weather forecast data can be retrieved based on this manually entered zip code. The zip code may instead be programmed to be determined via a Domain Name Service (DNS) if the retrieval of weather forecast data is made via the internet. The latter eases the burden of an installer from having to set the zip code manually and correctly.

(10) FIG. 2 is a diagram depicting a system enabling the present weather forecast based control scheme. A controller 6 can be adapted to receive a zip code input 8 manually set (e.g., as a zip code is entered locally via a keyboard) or automatically set by means of DNS via the internet 18 functionally connected to the controller. A setpoint temperature 10 can be manually set (e.g., entered locally via a keyboard at factory or locally) or automatically defaulted at build time to a default value, e.g., 120 degrees F. The controller 6 is configured to control a heating element 14 capable of heating a fluid to the setpoint temperature. A setpoint temperature is said to have been achieved when a temperature sensor reports an input 12 that matches this setpoint temperature.

(11) A temperature sensor 16 configured to provide the outdoor ambient temperature can be provided locally and directly to the controller 6. This data can also be provided via the internet 18 individually or as a bundle with weather forecast data 20 which can include not only raw temperature data but also heat index and wind chill factor data.

(12) FIG. 3 is a diagram depicting one example in which the setpoint temperature of a water heater is set based on forecasted temperature. In this example, the future outdoor temperature at a future time drops from the current outdoor temperature at the current time. A drop of the outdoor temperature can cause a user inside a building to feel cold as heat inside the building will be lost to the outdoors of the building at a greater rate. It may be true that, as the temperature of a space drops, a space heating system may add heat to replenish the lost heat until the temperature within the space has reached a level equivalent to the setpoint temperature of the space heating system. If the rate at which heat is lost to the outdoors is greater than the rate at which heat is replenished, it can take some time before the user feels comfortable again in the space being heated. Further, if pre-programmed space heating setpoints are used through a day, there is a chance that the space heating system is still struggling to meet a new higher setpoint when the outdoor temperature is dropping, causing a higher rate of heat loss. In order to make the user of a water heater feel more comfortable within a space, the setpoint temperature of a water heating system may be adjusted in a trend opposite that of the outdoor temperature. In other words, if the outdoor temperatures drops, the setpoint temperature of the heating system should be increased. The automatic adjustment of the water heating system setpoint temperature becomes particularly relevant when the user experiences events which cause the user to appreciate the increase in the setpoint temperature. For instance, an increase in the setpoint temperature is welcomed when the user has just experienced falling outdoor temperatures while the user was outside and wishes to take a hot shower. If the water heating control system is also used for space heating, such as in the case of a combined water heating and radiant floor heating system, the same adjustment made for the domestic water heating setpoint temperature can be applied to a radiant floor heating portion of the heating system. Conversely, if a user has just experienced a decreasing outdoor temperature, e.g., due to a warm front coming through the location, a return of the setpoint temperature to a lower normal temperature setpoint may be desirable. It is true that the user may choose to adjust the supply of hot water by adjusting the control knobs or levers of the faucets in mixing hot and cold water at the delivery point, however, the user typically has a pre-conceived temperature setting the user is accustomed to and does not typically like to deviate from the familiar control knob or lever settings.

(13) The present control system allows the user to physically set the control knobs or levers to familiar settings but still experience comfortable water temperature at the familiar settings. In one example, if the forecasted outdoor temperature is more than an amount of discrepancy or pre-determined threshold in magnitude lower than the current outdoor temperature, the temperature setpoint is to be adjusted up by an adjustment amount and in any subsequent heating of the water supply, this new adjustment will be incorporated. In one embodiment, the amount of discrepancy is about 2 degrees F. for those that value comfort over energy savings. In another embodiment, the amount of discrepancy is about 5 degrees F. for those that can tolerate sudden temperature drop better. This amount of discrepancy is preferably end user-adjustable or at the very least adjustable at installation, based on preferences of the end users. In one embodiment, the adjustment is about one degree F. In another embodiment, the adjustment amount is about 2 degrees F. However, there is a limit to which the setpoint temperature may be adjusted to. For instance, if the normal setpoint is 120 degrees F. The maximum setpoint temperature may be about 126 degrees F. and the minimum setpoint temperature may be about 114 degrees F.

(14) In some floor or space heating systems, an anti-freeze substance, e.g., Propylene Glycol, may be used and the floor or space heating systems may not be integral to water heating systems. In such cases, the floor or space heating systems may take identical or similar setpoint temperature adjustment outputs from the controllers of their corresponding water heating systems, although the magnitude of setpoint temperature adjustments may be different from the corresponding water heating systems.

(15) In tank-type applications, the present control system aids in getting the temperature of the water reserve to a new setpoint temperature, especially when the setpoint temperature of the reserve needs to be increased. In certain circumstances, setpoints may be momentarily set even higher than those required new higher setpoints to further elevate the temperature of portions of the reserve that has been brought to a previously lower setpoint temperature. In on-demand water heating systems, as hot water is prepared based on a new demand, this demand may only occur after a great deal of time has elapsed or a new demand may not occur for this new setpoint at all. In tank-type applications, a new setpoint may be readily and immediately applied as soon as it has been determined, as the reserve that has been heated to the previous setpoint temperature or the reserve that is being heated to the new setpoint temperature, must be used before new water is further drawn into the tank.

(16) In another embodiment, the wind chill factor and/or heat index are used instead of or in addition to the outdoor temperature to determine whether a water heater setpoint temperature adjustment is necessary. Wind chill factor is the perceived decrease in air temperature felt by the body on exposed skin due to the flow of air. When the apparent temperature is higher than the air temperature, the heat index may be used instead. According to National Digital Forecast Database, the apparent temperature is defined as the perceived temperature in degrees F. derived from either a combination of temperature and wind (or wind chill) or temperature and humidity (or heat index) for the indicated hour. When the temperature at a particular grid point falls to 50 degrees F. or less, wind chill will be used for that point for the apparent temperature. When the temperature at a grid point rises above 80 degrees F., the heat index will be used for apparent temperature. Between 51 and 80 degrees F., the apparent temperature will be the ambient air temperature.

(17) If wind chill factor and heat index are considered, a parameter, e.g., P, incorporating the the outdoor temperature, the wind chill factor, the heat index and weighting factors for each may be used. For example P=K1*T+K2*WCF+K3*HI where T is outdoor temperature, WCF is wind chill factor, HI is the heat index, K1 is the weighting factor for T, K2 is the weighting factor for WCF and K3 is the weighting factor for HI. Any one of parameters T, WCF and HI may be omitted from the computation of P although using all three will provide increased comfort to the users. Therefore in using the P instead of the outdoor temperature alone, a P value is calculated for the future conditions and a P value is calculated for the current conditions. The results are compared and if the difference exceeds a pre-determined value, an adjustment to the setpoint temperature of the water heating control system is made. Forecasted and current wind chill factor (a function of wind speed and temperature) and heat index (a function of temperature and dew point temperature or humidity) are preferably obtained via forecasted data package although it is also possible to obtain such parameters locally with additional equipment, e.g., wind meter for obtaining wind speed and psychrometer or hygrometer for obtaining humidity or dew point. It shall be noted that individual components, e.g., differences of K1*T, K2*WCF or K3*HI between the forecasted and current data may be first computed and summed up to arrive at the same result as the difference between the forecasted and current P.

(18) The detailed description refers to the accompanying drawings that show, by way of illustration, specific aspects and embodiments in which the present disclosed embodiments may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice aspects of the present invention. Other embodiments may be utilized, and changes may be made without departing from the scope of the disclosed embodiments. The various embodiments can be combined with one or more other embodiments to form new embodiments. The detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, with the full scope of equivalents to which they may be entitled. It will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of embodiments of the present invention. It is to be understood that the above description is intended to be illustrative, and not restrictive, and that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Combinations of the above embodiments and other embodiments will be apparent to those of skill in the art upon studying the above description. The scope of the present disclosed embodiments includes any other applications in which embodiments of the above structures and fabrication methods are used. The scope of the embodiments should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.