Preconditioning controls and methods for an environmental control system

Patent metadata

Field	Value
Publication number	US-9470430-B2
Application number	US-201414155225-A
Country	US
Kind code	B2
Filing date	Jan 14, 2014
Priority date	Sep 30, 2012
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

A method of preconditioning an enclosure includes providing a thermostat and computing a set of preconditioning criteria information (PCI) with the thermostat. The computed PCI is typically representative of time and ambient temperature conditions for which preconditioning should be performed. The PCI may be stored in memory and used to compare against a current time and current ambient temperature condition of the enclosure to determine whether to enter the thermostat into a preconditioning state. If a determination is made that the PCI criteria are satisfied, the thermostat may be entered into the preconditioning state to heat or cool the enclosure. One or more of these processes may be performed while a processor of the thermostat is in a relatively high power mode or relatively low power mode.

First claim

What is claimed is:

1. An HVAC control device comprising:
a processing system that receives ambient temperature information for an enclosure and information from an HVAC schedule, the HVAC schedule including a first setpoint characterized by a first setpoint temperature and a first setpoint time, the HVAC schedule including a second setpoint characterized by a second setpoint temperature and a second setpoint time, the first setpoint time and second setpoint time defining a first time interval therebetween, said processing system being configured to control the HVAC system to precondition the enclosure during at least a part of said first time interval such that the ambient temperature reaches substantially said second setpoint temperature by said second setpoint time, wherein the processing system controls the HVAC system to precondition the enclosure by:
processing the second setpoint temperature in conjunction with first information derived from a historical record of previous heating and cooling cycles for said HVAC system as controlled by the HVAC control device to compute a set of preconditioning criteria information (PCI) representative of time and ambient temperature conditions for which the preconditioning should be performed;
during said time interval, comparing a current time and current ambient temperature against said PCI to determine whether to enter into a preconditioning state; and
when it is so determined, entering into said preconditioning state upon a determination that the PCI criteria are satisfied.

2. The HVAC control device of claim 1 , wherein the set of PCI is computed based on a time to temperature for the enclosure that defines a change in temperature response for the enclosure when subjected to a heating or cooling operation.

3. The HVAC control device of claim 2 , wherein the time to temperature for the enclosure is adjusted for a subsequent preconditioning operation based on a response of the enclosure to said preconditioning, said response being included in said historical record of said previous heating and cooling cycles.

4. The HVAC control device of claim 1 , wherein the processing system comprises:
a first processor characterized by at least a relatively high electrical power-consuming first mode of operation and a relatively low electrical power-consuming second mode of operation, wherein said processing is performed by said first processor; and
a second processor characterized by a relatively low electrical power-consuming mode of operation, wherein said comparing is performed by said second processor.

5. The HVAC control device of claim 4 , wherein said set of PCI is computed via said first processor, and wherein said set of PCI is communicated to said second processor for comparing said current time and current ambient temperature against said PCI.

6. The HVAC control device of claim 5 , wherein communicating said set of PCI to said second processor comprises communicating a partial set of said set of PCI, said partial set covering a time interval extending to either of: 1) an anticipated or requested time of said first processor entering into said first mode of operation, and 2) said second setpoint time.

7. The HVAC control device of claim 4 , wherein comparing said current time and current ambient temperature against said PCI to determine whether to enter into said preconditioning state comprises:
determining an amount of time relative to said first processor entering into said second mode of operation;
determining an ambient temperature condition of said PCI associated with said amount of time, the ambient temperature condition representing a temperature for which preconditioning should be performed; and
comparing said current ambient temperature with said ambient temperature condition to determine whether said PCI criteria are satisfied.

8. The HVAC control device of claim 4 , wherein processing said second setpoint temperature in conjunction with said first information to compute said set of PCI comprises:
determining a first time duration defined by said second setpoint time and a first time within said first time interval;
deriving from said historical record, a first ambient temperature condition associated with said first time duration that represents a temperature for which preconditioning should be performed;
determining a second time duration defined by said first time and a second time within said first time interval;
deriving from said historical record, a second ambient temperature condition associated with said second time duration that represents an additional temperature for which preconditioning should be performed; and
determining at least one addition time duration within said first time interval; and
deriving at least one additional ambient temperature condition representative of at least one additional temperature for which preconditioning should be performed.

9. The HVAC control device of claim 1 , wherein said set of PCI comprises either or both an upper range representative of conditions for which preconditioning cooling should be performed and a lower range representative of conditions for which preconditioning heating should be performed.

10. The HVAC control device of claim 1 , wherein said set of PCI comprise a step function, and wherein preconditioning is limited to a defined duration.

11. A method comprising:
providing an HVAC control device comprising:
a processing system that receives ambient temperature information for an enclosure and information from an HVAC schedule, the HVAC schedule including a first setpoint characterized by a first setpoint temperature and a first setpoint time, the HVAC schedule including a second setpoint characterized by a second setpoint temperature and a second setpoint time, the first setpoint time and second setpoint time defining a first time interval therebetween, said processing system being configured to control the HVAC system to precondition the enclosure during at least a part of said first time interval such that the ambient temperature reaches substantially said second setpoint temperature by said second setpoint time;
processing the second setpoint temperature in conjunction with first information derived from a historical record stored of previous heating and cooling cycles for said HVAC system as controlled by said HVAC control device to compute a set of preconditioning criteria information (PCI) representative of time and ambient temperature conditions for which the preconditioning should be performed;
during said time interval, comparing a current time and current ambient temperature against said PCI to determine whether to enter said HVAC control device into a preconditioning state; and
entering said HVAC control device into said preconditioning state upon a determination that the PCI criteria are satisfied.

12. The method of claim 11 , wherein said set of PCI is computed based on a time to temperature for said enclosure.

13. The method of claim 12 , wherein said time to temperature is adjusted for a subsequent preconditioning operation based on a response of said enclosure to said preconditioning.

14. The method of claim 11 , wherein said processing system comprises:
a first processor characterized by at least a relatively high electrical power-consuming first mode of operation and a relatively low electrical power-consuming second mode of operation, wherein said processing is performed by said first processor; and
a second processor characterized by a relatively low electrical power-consuming mode of operation, wherein said comparing is performed by said second processor.

15.

Assignees

• Google Inc

Inventors

• Stefanski Mark
• Matsuoka Yoky

Classifications

• F24F2120/00

  Control inputs relating to users or occupants · CPC title

• F24F11/88

  Electrical aspects, e.g. circuits · CPC title

• F24F11/66

  Sleep mode · CPC title

• F24F11/64

  using pre-stored data · CPC title

• F24F11/58

  using Internet communication · CPC title