US008131497B2
`
`US 8,131,497 B2
`(10) Patent No.:
`a2) United States Patent
`Steinberget al.
`(45) Date of Patent:
`*Mar. 6, 2012
`
`
`(54) SYSTEM AND METHOD FOR CALCULATING
`THE THERMALMASSOF A BUILDING
`
`(75)
`
`:
`:
`Inventors: John Douglas Steinberg, Millbrae, CA
`(US); Scott Douglas Hublou, Redwood
`City, CA (US)
`(73) Assignee: EcoFactor, Inc., Millbrae, CA (US)
`(*) Notice:
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`USC. 154(b) by 0 days.
`This patent is subject to a terminal dis-
`claimer.
`
`(21) Appl. No.: 12/959,225
`
`(22)
`
`Filed:
`
`(65)
`
`Dec.2, 2010
`oo.
`,
`Prior Publication Data
`
`Mar.31, 2011
`US 2011/0077896 Al
`Related US. Application Dat
`elateg
`=). Application Mata
`(63) Continuation of application No. 12/211,733, filed on
`Sep. 16, 2008, now Pat. No. 7,848,900.
`(60) Provisional application No. 60/994,011, filed on Sep.
`17, 2007.
`Int.Cl
`(51)
`(2006.01)
`GC01K 900
`702/130: 702/182
`,
`52) US.Cl
`?
`ee eeeToren teens
`(52)
`(58) Field of Classification Search o0...0000..
`702/130,
`702/182; 700/276, 277, 278; 236/91 D;
`an
`165/58, 200, 287
`See application file for complete searchhistory.
`.
`References Cited
`U.S. PATENT DOCUMENTS
`4.136.732 A ,
`1979 D
`al
`emarayetal.
`;
`;
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`acka et
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`6,260,765 Bl
`7/2001 Natale etal.
`(Continued)
`
`OTHER PUBLICATIONS
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`Arens, et al., “How Ambient Intelligence Will Improve Habitability
`and Energy Efficiency in Buildings”, 2005, research paper, Centerfor
`the Built Environment, Controls and Information Technology.
`(Continued)
`
`Primary Examiner — Edward Raymond
`Assistant Examiner — Elias Desta
`(74) Attorney, Agent, or Firm — Knobbe, Martens, Olson &
`Bear, LLP
`
`ABSTRACT
`(57)
`The invention comprises a system for calculating a value for
`the effective thermal massof a building. The climate control
`system obtains temperature measurements from atleasta first
`location conditioned by the climate system. One or more
`processors receive measurements of outside temperatures
`from at least one source other than the control system and
`compare the temperature measurements from the first loca-
`tion with expected temperature measurements. The expected
`temperature measurementsare basedat least in part upon past
`temperature measurements obtained by said HVAC control
`system andsaid outside temperature measurements. The pro-
`cessors then calculate one or more rates of change in tem-
`perature at saidfirst location.
`
`12 Claims, 13 Drawing Sheets
`
`INPUT OUTSIDE[~7502
`CLIMATE DATA
`
`INPUT HVAC
`DUTY CYCLE DATA
`
`1304
`
`
`
`
`
`
`SEND MESSAGE TO
`
`HOMEOWNER RE: PROBLEM
`
`
`
` SET
`
`
`
`
`NPI
`UT INSIDE
`TEMPERATURE DATA
`
`1506
`
`INPUT PROFILE oatal 1308
`INPUT
`(510
`COMPARATIVE DATA
`
`
`
` DOES PATTERN
`
`CALCULATE EXPECTED]-psy
`INSIDE TEMPERATURE
`READING
`TARGET TEMPERATURE BASED
`ON CALCULATED DATA FOR
`DURATION OF DISTORTION EVENT
`
`001
`
`GOOGLE 1026
`GOOGLE1026
`
`001
`
`

`

`US 8,131,497 B2
`
`Page 2
`
`U.S. PATENT DOCUMENTS
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`Honeywell, W7600/W7620 Controller Reference Manual,
`HW0021207, Oct. 1992.
`Johnson Controls, Touch4 building automation system brochure,
`2007.
`Kilicotte, et al., “Dynamic Controls for Energy Efficiency and.
`Demand. Response: Framework Concepts and a New Construction
`Study Case in New York”, Proceedings of the 2006 ACEEE Summer
`Study of Energy Efficiency in Buildings, Pacific Grove. CA, Aug.
`13-18, 2006.
`Lin, et al., “Multi-Sensor Single-Actuator Control of HVAC Sys-
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`Wang,et al., “Opportunities to Save Energy and Improve Comfort by
`Using Wireless Sensor Networks in Buildings,” (2003), Center for
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`Wetter, et al., A comparison of deterministic and probabilistic opti-
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`Building and Environment 39, 2004, pp. 989-999.
`
`OTHER PUBLICATIONS
`
`* cited by examiner
`
`002
`
`002
`
`

`

`U.S. Patent
`
`Mar.6, 2012
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`Sheet 1 of 13
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`US 8,131,497 B2
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`G:
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`L L
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`003
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`003
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`

`

`U.S. Patent
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`Mar.6, 2012
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`Sheet 2 of 13
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`US 8,131,497 B2
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`
`
`170
`
`702
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`1060
`
`DATABASE
`
`DATABASE DEMAND REDUCTION
`
`SERVICE SERVERS
`
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`
`004
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`

`

`U.S. Patent
`
`Mar.6, 2012
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`Sheet 3 of 13
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`US 8,131,497 B2
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`U.S. Patent
`
`Mar.6, 2012
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`Sheet 4 of 13
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`US 8,131,497 B2
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`

`U.S. Patent
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`Mar.6, 2012
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`Sheet 5 of 13
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`US 8,131,497 B2
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`JOO
`
`THERMOSTAT SETTINGS
`
`HVAC HARDWARE TRANSACTION
` TEMPERATURE
`
`PRODUCT & SERVICEi
`
`4700
`
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`
`
`
`L1G, 3
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`

`

`U.S. Patent
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`Mar.6, 2012
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`Sheet 6 of 13
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`US 8,131,497 B2
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`
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`12
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`

`

`U.S. Patent
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`Mar.6, 2012
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`Sheet 7 of 13
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`US 8,131,497 B2
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`12 Noon
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`6 PM
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`

`

`U.S. Patent
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`Mar.6, 2012
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`Sheet 8 of 13
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`US 8,131,497 B2
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`12 Noon
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`6 PM
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`12
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`

`

`U.S. Patent
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`Mar.6, 2012
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`Sheet 9 of 13
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`US 8,131,497 B2
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`502
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`12
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`6 AM
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`12 Noon
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`6 PM
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`

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`U.S. Patent
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`Mar.6, 2012
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`Sheet 10 of 13
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`US 8,131,497 B2
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`95
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`

`

`U.S. Patent
`
`Mar.6, 2012
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`Sheet 11 of 13
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`US 8,131,497 B2
`
`INPUT OUTSIDE
`CLIMATE DATA
`
`INPUT HVAC
`DUTY CYCLE DATA
`
`INDEX
`
`INPUT PRIOR INSIDE
`TEMPERATURE DATA
`
`BUILDING/USER
`PROFILE
`
`INPUT CURRENT
`INSIDE
`TEMPERATURE
`
`CALCULATE
`THERMAL MASS
`
`Ll. LL
`
`013
`
`013
`
`

`

`U.S. Patent
`
`Mar.6, 2012
`
`Sheet 12 of 13
`
`US 8,131,497 B2
`
`1218
`
`
`DOES PATTERN
`REPORT
`INPUT OUTSIDE|-7227
`YES) CLOGGED
`MATCH CLOGGED
`CLIMATE DATA
`FILTER PATTERN
`
`
`
`
`
`
`
`NO
`
`FILTER
`
`INPUT HVAC
`DUTY CYCLE DATA
`
`1204
`
`INPUT INSIDE
`TEMPERATURE DATA
`
`1206
`
`
`
`
`
`1222
`
` YES REPORT
`
`COOLANT LEAK
`
`
`
`DOES PATTERN
`MATCH REFRIGERANT
`LEAK
`
`?
`
`
`
`NO
`
`INPUT PROFILE DATA
`
`1208
`
`INPUT
`COMPARATIVE DATA
`
`7270
`
`( (426
`
`
`OochOPE
`
`WINDOW/DOOR
`?
`
`NO
`
`228
`
`YES|
`
`REPORT OPEN
`WINDOW/DOOR
`
`CALCULATE
`RELATIVE
`
`EFFICIENCY
`
`1242
`
`12/44
`
`
`HAS RELATIVE
`NO
`EFFICIENCY
`
`CHANGED
`?
`
`YES
`
`
`
`
` PATTERN MATCH
`
`
`REPORT
`PROBLEM n
`
`PROBLEM n
`
`1276
`
`END
`
`REPORT UNKNOWN
`PROBLEM
`
`
`
`L1G, L2
`
`014
`
`014
`
`

`

`U.S. Patent
`
`Mar.6, 2012
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`Sheet 13 of 13
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`US 8,131,497 B2
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`INPUT HISTORICAL DATA
`
`1318
`
`INPUT SOLAR
`PROGRESSION DATA
`
`1320
`
` DATA
`
`CALCULATE EXPECTED
`DURATION OF
`DISTORTION EVENT
`
`CALCULATE EXPECTED|—yz72
`|
`INSIDE TEMPERATURE
`
`INPUT OUTSIDE
`CLIMATE DATA
`
`1502
`
`INPUT HVAC
`DUTY CYCLE DATA
`
`1504
`
`INPUT INSIDE
`TEMPERATURE DATA
`
`1306
`
`INPUT PROFILE DATA
`
`1308
`
`INPUT
`COMPARATIVE DATA
`
`13570
`
`READING
`
`1314
`
`DOES INSIDE
`TEMPERATURE READING
`DIVERGE FROM
`PREDICTED VALUE
`?
`
`
`
`
`NO
`
`YES
`
`?
`
`
`1526
`
`
`
`
`1530
`
`SET TARGET TEMPERATURE BASED
`ON CALCULATED DATA FOR
`DURATION OF DISTORTION EVENT
`
`SEND MESSAGE TO
`HOMEOWNER RE: PROBLEM
`
`LIG. LF
`
`015
`
`015
`
`

`

`US 8,131,497 B2
`
`1
`SYSTEM AND METHOD FOR CALCULATING
`THE THERMAL MASSOF A BUILDING
`
`2
`advance with programmable thermostats is that they can shift
`between multiple present temperaturesat different times.
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`SUMMARY OF THE INVENTION
`
`This application is a continuation of U.S. patent applica-
`tion No. 12/211,733, filed Sept. 16, 2008 which claimspri-
`ority under 35 U.S.C. §119(e) to U.S. Provisional Application
`No. 60/994,011, filed Sept. 17, 2007, the entirety of each of
`whichis hereby incorporated herein by reference andis to be
`considered part of this specification.
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`This invention relates to the use of thermostatic HVAC
`
`controls that are connected to a computer network. More
`specifically, communicating thermostats are combined with a
`computer network to calculate the thermal mass ofa struc-
`ture.
`
`2. Background
`Climate control systems such as heating and cooling sys-
`temsfor buildings (heating, ventilation and cooling, or HVAC
`systems) have been controlled for decades by thermostats. At
`the mostbasic level, a thermostat includes a meansto allow a
`user to set a desired temperature, a means to sense actual
`temperature, and a meansto signal the heating and/or cooling
`devices to turn on oroff in order to try to change the actual
`temperature to equal the desired temperature. The most basic
`versions of thermostats use components such as a coiled
`bi-metallic spring to measure actual temperature and a mer-
`cury switch that opens or completes a circuit when the spring
`coils or uncoils with temperature changes. More recently,
`electronic digital thermostats have become prevalent. These
`thermostats use solid-state devices such as thermistors or
`
`thermal diodes to measure temperature, and microprocessor-
`basedcircuitry to control the switch and to store and operate
`based upon user-determined protocols for temperature vs.
`time.
`
`These programmable thermostats generally offer a very
`restrictive user interface, limited by the cost of the devices,
`the limited real estate of the small wall-mounted boxes, and
`the inability to take into account more than twovariables: the
`desired temperature set by the user, and the ambient tempera-
`ture sensed by the thermostat. Users can generally only set
`one series of commandsperday, and in order to change one
`parameter(e.g., to changethe late-night temperature) the user
`often has to cycle through several other parameters by repeat-
`edly pressing one or two buttons.
`Because the interface of programmable thermostats is so
`poor, the significant theoretical savingsthat are possible with
`them (sometimescited as 25% of heating and cooling costs)
`are rarely realized. In practice, studies have fund that more
`than 50% of users never program their thermostats at all.
`Significant percentages of the thermostats that are pro-
`grammed are programmed sub-optimally, in part because,
`once programmed, people tend to not to re-invest the time
`needed to changethe settings very often.
`A second problem with standard programmable thermo-
`stats is that they represent only a small evolutionary step
`beyondthefirst, purely mechanical thermostats. Like thefirst
`thermostats, they only have two input signals—ambient tem-
`perature and the preset desired temperature. The entire
`
`10
`
`15
`
`20
`
`25
`
`30
`
`40
`
`45
`
`50
`
`60
`
`65
`
`There are many other sources of information that could be
`used to increase comfort, decrease energy use, or both. For
`example, outside temperature and humidity strongly affect
`subjective comfort. On a 95 degree, 90 percent humidity day
`in August, when people tend to dress in lightweight clothing,
`a house cooled to 70 degrees will feel cool or even uncom-
`fortably cold. On a below-freezing day in January, when
`people tend to wear sweaters and heavier clothes, that same
`70 degree home will feel too warm. It would therefore be
`advantageousfor a thermostat system to automatically incor-
`porate information about external weather conditions when
`setting the desired temperature.
`Thermostats are used to regulate temperature for the ben-
`efit of the occupants in a given space. (Usually this means
`people, but it can of course also meancritical equipment, such
`as in a room filled with computer equipment.) In general,
`thermostats read temperature from the sensor located within
`the “four comers”ofthe thermostat. With a properly designed
`system, the thermostat may well be located such that the
`temperature read at the precise location of the thermostat
`accurately reflects the conditions where the human(orother)
`occupants tend to be. But there are many reasons and circum-
`stances in which that will not be the case. A single thermostat
`may produce accurate readings in some circumstances but not
`others; it may be located in a place far from the occupants, or
`too far from the ductwork controlled by the thermostat, etc. In
`one house, for example, the thermostat may be located in a
`spot that receives direct sunlight on hot afternoons. This could
`cause the thermostat to sense that the local ambient tempera-
`ture is extremely high, and as a result signal the A/C to run too
`long, making the rest of the home too cold, and wasting
`considerable energy. In another house, the thermostat may be
`located in a hallway without ductwork or where the nearby
`ducts have been closed. In such a scenario, the thermostat is
`likely to (correctly) report cold temperatures in the winter,
`leading the heating system to overheat the rest of the house
`and waste considerable energy.
`These problems can be reduced or eliminated through use
`of additional remote temperature sensors connected to the
`thermostat’s control circuitry. However, such systems require
`additional hardware, additional thermostat complexity, and
`skilled installation and configuration.
`It would therefore be desirable for a thermostat system
`using only a single temperature sensor to take such sub-
`optimalinstallations into accountandto correct for the erro-
`neous readings generated by such thermostats.
`Different structures will respond to changes in conditions
`such as external temperature in different ways. For example,
`houses built 50 or more years ago will generally havelittle or
`no insulation, be poorly sealed, and have simple single-glazed
`windows. Such houses will do a very poor job of retaining
`internal heat in the winter and rejecting external heat in the
`summer. In the absence of applications of thermal measures
`suchasheating and air conditioning,the inside temperaturein
`such houses will trend to track outside temperatures very
`closely. Such houses maybesaid to have low thermal mass. A
`house built in recent years, using contemporary techniques
`for energyefficiency such as high levels ofinsulation, double-
`glazed windowsandother techniques, will, in the absence of
`intervention, tend to absorb external heat and release internal
`heat very slowly. The newer house can be thought ofas having
`higher thermal mass than the older house.
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`A conventional thermostat has no mechanism by whichit
`might take the thermal mass ofthe structure into account, but
`thermal mass significantly affects many parameters relating
`to energy efficiency.
`Thecost to an electric utility to produce powervaries over
`time. Indeed,the cost ofproduction between low demand and
`peak demand periods can vary by as much as an order of
`magnitude. Traditionally, residential customers paid the same
`price regardless of time or the cost to produce. Thus consum-
`ers have hadlittle financial incentive to reduce consumption
`during periods of high demand and high production cost.
`Manyelectric utilities are now seeking to bring various forms
`of variable rates to the retail energy markets. Under such
`schemes, consumers can reduce costs by taking into account
`not just how much energy they use, but when theyuseit.
`Thus many consumers now can see real benefits from opti-
`mizing notjust the total number ofkilowatt-hoursofelectric-
`ity consumed, but also optimizing whenit is used. The opti-
`mum strategy for energy use over time will vary based upon
`many variables, one of which is the thermal mass of the
`structure being heated or cooled. In a structure with high
`thermal mass, heating and cooling can effectively be shifted
`away from high costperiods to lowercost “shoulder”periods
`with little or no effect on comfort. If, for example, a utility
`charges much higher rates on hot summer afternoons, it is
`likely that pre-cooling a high-thermal mass structure just
`before the high-cost period and then shutting down the air
`conditioning during the peak will allow the house to remain
`comfortable. But in a house with low thermal mass, the ben-
`efits of pre-cooling will quickly dissipate, and the house will
`rapidly become uncomfortable if the air conditioning is shut
`off. Thus it would be advantageousfor a temperature control
`system to take thermal mass into account whensetting desired
`temperatures.
`Manyfactors affect the efficiency of HVAC systems. Some
`maybe thoughtof as essentially fixed, such as the theoretical
`efficiency of a central air conditioner (often expressed as its
`SEERrating), the matching of a given system to the charac-
`teristics of a given home,the location and size of forced-air
`ductwork, etc. Other contributors to efficiency are more
`dynamic, such as cloggedfilters, refrigerant leaks, duct leak-
`age and “pop-offs,” and thelike.
`Mostofthese problemsare likely to manifest themselves in
`the form of higher energy bills. But the “signature” of each
`different problem can be discerned from the way in which
`each such problem affects the cycle times of a given HVAC
`system over time andrelative to weather conditions and the
`performance of other HVAC systemsin other houses. If two
`otherwise identical houses are located next door to each other
`
`and have gas furnaces, but oneis rated at 50,000 BTUsand the
`other is rated at 100,000 BTUs, the cycle times for the higher-
`capacity furnace should be shorterthan for the lower-capacity
`unit. Ifboth of those same houseshaveidentical furnaces, but
`onehas a cloggedfilter, the cycle times should be longer in the
`house with the cloggedfilter. Because cycling of the HVAC
`system is controlled by the thermostat, those differences in
`cycle time would be reflected in the data sensed by and
`control signals generated by the thermostat. It would be
`advantageous for a thermostat system to be able to use that
`information to diagnose problems and make recommenda-
`tions based uponthatdata.
`These needsaresatisfied byat least one embodimentof the
`invention that includes a system for calculating a valuefor the
`effective thermal mass of a building comprising: at least one
`HVAC control system that measures temperature at least a
`first location conditioned by said HVAC system, and report-
`ing said temperature measurements as well as the status of
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`said HVAC control system; one or more processors that
`receive measurements of outside temperatures from at least
`one source other than said HVAC control systems and com-
`pare said temperature measurements from said first location
`with expected temperature measurements wherein the
`expected temperature measurementsare basedatleast in part
`upon past temperature measurements obtained by said HVAC
`control system and said outside temperature measurements;
`and one or more databasesthatstore at least said temperatures
`measuredat said first location over time; calculating one or
`morerates of change in temperatureatsaid first location; and
`relating said calculated rates of change to said outside tem-
`perature measurements.
`Another embodiment includes a system for calculating a
`value for the operational efficiency of an HVAC system com-
`prising at least one HVAC control system that measures tem-
`perature at least a first location conditioned by said HVAC
`system, and reporting said temperature measurements as well
`as the status of said HVAC control system; one or more
`processors that receive measurements of outside tempera-
`tures from at least one source other than said HVAC control
`
`systems and compare said temperature measurements from
`said first location with expected temperature measurements
`wherein the expected temperature measurements are based at
`least in part upon past temperature measurements obtained by
`said HVAC control system and said outside temperature mea-
`surements; and one or more databasesthat store at least said
`temperatures measuredatsaid first location over time; calcu-
`lating one or morerates of change in temperatureat said first
`location for periods during which the status of the HVAC
`system is “on”; calculating one or more rates of change in
`temperature at saidfirst location for periods during which the
`status of the HVAC system is “off; and relating said calcu-
`lated rates of’ change to said outside temperature measure-
`ments.
`
`A further embodiment includes a system for evaluating
`changes in the operationalefficiency ofan HVAC system over
`time comprising at least one HVAC control system that mea-
`sures temperature atleast a first location conditioned by said
`HVACsystem, and reporting said temperature measurements
`as well as the status of said HVAC control system; one or
`more processors that recetve measurements of outside tem-
`peratures from at least one source other than said HVAC
`control systems and comparesaid temperature measurements
`from said first location with expected temperature measure-
`ments wherein the expected temperature measurements are
`based at least in part upon past temperature measurements
`obtained by said HVAC control system andsaid outside tem-
`perature measurements; and one or more databasesthat store
`at least said temperatures measuredat said first location over
`time.
`A further embodimentincludes a system for detecting and
`correcting for anomalous behavior in HVAC control systems
`comprising a first HVAC control system that measures tem-
`perature at least a first location conditioned by said first
`HVACsystem, and reporting said temperature measurements
`as well as the status ofsaid first HVAC control system; at least
`a second HVACcontrol system that measures temperatureat
`least a second location conditioned by said second HVAC
`system, and reporting said temperature measurements as well
`as the status of said second HVAC control system; one or
`more processors that recetve measurements of outside tem-
`peratures from at least one source other than said first and
`second HVACcontrol systems and compare said temperature
`measurements from said first HVAC controls system and said
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`US 8,131,497 B2
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`5
`second HVAC control system and said outside temperature
`measurements; and one or more databases that store said
`temperatures measurements.
`In at least one embodiment, the invention comprises a
`thermostat attached to an HVAC system, a local network
`connecting the thermostat to a larger network such as the
`Internet, and one or more additional thermostats attached to
`the network, and a server in bi-directional communication
`with a plurality of such thermostats. The server logs the
`ambient temperature sensed by each thermostat vs. time and
`the signals sent by the thermostats to their HVAC systems.
`The server preferably also logs outside temperature and
`humidity data for the geographic locations for the buildings
`served by the connected HVAC systems. Such informationis
`widely available from various sources that publish detailed
`weather information based on geographic areas such as by
`ZIP code. Theserver also stores other data affecting the load
`upon the system, such as specific model of HVAC system,
`occupancy, building characteristics, etc. Some of this data
`may be supplied by the individual users of the system, while
`other data may come from third-party sources such as the
`electric and other utilities who supply energyto those users.
`Combining these data sources will also allow the server to
`calculate the effective thermal mass of the structures condi-
`tioned by those thermostats. By combining data from mul-
`tiple thermostats in a given neighborhood, the system can
`correctfor flawsin the location ofa given thermostat, and can
`evaluate the efficiency of a given system, as well as assist in
`the diagnosis of problems and malfunctions in such systems.
`This and other advantages of, certain embodiments of the
`invention are explained in the detailed description and claims
`that make reference to the accompanying diagramsand flow-
`charts.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 shows an example of an overall environment in
`which an embodimentof the invention may be used.
`FIG.2 showsa high-level illustration ofthe architecture of
`a network showing the relationship between the major ele-
`ments of one embodimentof the subject invention.
`FIG. 3 shows an embodimentof the website to be used as
`
`part of the subject invention.
`FIG. 4 showsa high-level schematic ofthe thermostat used
`as part of the subject invention.
`FIG. 5 shows one embodimentof the database structure
`
`usedas part of the subject invention
`FIGS. 6a and 66 show graphical representations of inside
`and outside temperatures in two different homes, one with
`high thermal mass and one with low thermal mass.
`FIGS. 7a and 76 show graphical representations of inside
`and outside temperatures in the same homesas in FIGS. 6a
`and 65, showingthe cycling ofthe air conditioning systems in
`those houses.
`FIGS. 8a and 84 show graphical representations of inside
`and outside temperatures in the same homeasin FIGS. 6a and
`7a, showing the cycling ofthe air conditioning on two differ-
`ent days in order to demonstrate the effect of a change in
`operating efficiency on the parameters measured bythe ther-
`mostat.
`
`FIGS. 9a and 964 show the effects of employing a pre-
`cooling strategy in two different houses.
`FIGS. 10a and 106 show graphical representations of
`inside and outside temperatures in two different homes in
`order to demonstrate how the system can correct for errone-
`ous readingsin one houseby referencing readings in another.
`
`6
`FIG. 11 is a flowchart illustrating the steps involved in
`calculating the effective thermal mass of a home using the
`subject invention.
`FIG. 12 is a flowchart illustrating the steps involved in
`determining whether an HVAC system has developed a prob-
`lem that impairs efficiency using the subject invention.
`FIG. 13 is a flowchart illustrating the steps involved in
`correcting for erroneous readings in one housebyreferencing
`readings in another using the subject invention.
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENT
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`FIG. 1 shows an example of an overall environment 100 in
`which an embodiment of the invention may be used. The
`environment 100 includesan interactive communication net-
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`work 102 with computers 104 connected thereto. Also con-
`nected to network 102 are one or more server computers 106,
`which store information and make the information available
`
`to computers 104. The network 102 allows communication
`between and among the computers 104 and 106.
`Presently preferred network 102 comprises a collection of
`interconnected public and/or private networksthat are linked
`to together by a set of standard protocols to form a distributed
`network. While network 102 is intended to refer to whatis
`now commonlyreferred to as the Internet, it is also intended
`to encompass variations which may be made in the future,
`including changesadditions to existing standard protocols.
`When a user of the subject invention wishes to access
`information on network 102, the buyer initiates connection
`from his computer 104. For example, the user invokes a
`browser, which executes on computer 104. The browser, in
`turn, establishes a communication link with network 102.
`Once connected to network 102, the user can direct the
`browser to access information on server 106.
`
`One popular part of the Internet is the World Wide Web.
`The World Wide Web contains a large number of computers
`104 and servers 106, which store HyperText Markup Lan-
`guage (HTML) documents capable of displaying graphical
`and textual information. HTMLis a standard coding conven-
`tion and set of codes for attaching presentation and linking
`attributes to informational content within documents.
`
`The servers 106 that provide offerings on the World Wide
`Webare typically called websites. A website is often defined
`by an Internet address that has an associated electronic page.
`Generally, an electronic page is a documentthat organizes the
`presentation of text graphical images, audio and video.
`In addition to the Internet, the network 102 can comprise a
`wide variety of interactive communication media. For
`example, network 102 can include local area networks, inter-
`active television networks, telephone networks, wireless data
`systems, two-way cable systems, andthelike.
`In one embodiment, computers 104 and servers 106 are
`conventional computers that are equipped with communica-
`tions hardware such as modem or a network interface card.
`The computers include processors such as those sold by Intel
`and AMD. Other processors may also be used, including
`general-purpose processors, multi-chip processors, embed-
`ded processors andthelike.
`Computers 104 can also be handheld and wireless devices
`suchaspersonaldigital assistants (PDAs), cellular telephones
`and other devices capable of accessing the network.
`Computers 104 utilize a browser configured to interact
`with the World Wide Web. Such browsers may include
`Microsoft Explorer, Mozilla, Firefox, Opera or Safari. They
`mayalso include browsers used on handheld and wireless
`devices.
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`US 8,131,497 B2
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`7
`The storage medium may comprise any methodofstoring
`information.
`It may comprise random access memory
`(RAM), electronically erasable programmable read only
`memory (EEPROM), read only memory (ROM), hard disk,
`floppy disk, CD-ROM,optical memory, or other method of
`storing data.
`Computers 104 and 106 may use an operating system such
`as Microsoft Windows, Apple Mac OS, Linux, Unix or the
`like.
`
`8
`The website will allow users of connected thermostats 250
`to create personal accounts. Each user’s account will store
`information in database 900, which tracks various attributes
`relative to users of the site. Such attributes may include the
`make and modelofthe specific HVAC equipmentin the user’s
`home; the age and square footage of the home, the solar
`orientation of the home, the location of the thermostat in the
`home,the user’s preferred temperature settings, whether the
`useris a participant in a demand reduction program,etc.
`
`Computers 106 may includearangeofdevices that provide As shownin FIG.3, the website 200 will permit thermostat
`information, sound, graphics andtext, and mayuse a variety
`users to perform through the web browsersubstantially all of
`of operating systems and software optimized for distribution
`the programming functionstraditionally performed directly
`of content via networks.
`at the physical thermostat, such as temperatureset point