HVAC control system

• US 8,412,381 B2
• Filed: 03/24/2010
• Issued: 04/02/2013
• Est. Priority Date: 03/24/2010
• Status: Active Grant

• Current Assignee: Microsoft Corporation, Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Nikovski, Daniel, Laughman, Christopher
• Primary Examiner(s): ORTIZ RODRIGUEZ, CARLOS R
• Application Number:
  US12/730,326
• Publication Number:
  US 20110238222A1
• Time in Patent Office: 1,105 Days
• Field of Search: 700/9, 700/12, 700/275, 700/276, 700/291, 700/299, 700/300, 701/412, 701/414, 701/415, 701/423, 701/434
• US Class Current: 700/276
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/56 Remote control
• CPC Class Codes: F24F 11/58 using Internet communication
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2120/12 Position of occupants

Abstract

A method controls a heating, ventilation, air conditioning (HVAC) system by determining a travel time from a mobile site to a fixed site, and determining a conditioning time for a HVAC system at the fixed site. The HVAC is maintained in an ON state if the travel time is less than the conditioning time, and otherwise maintaining the HVAC in an OFF state, and wherein the conditioning time is determined using a building thermal model.

Claims

1. A method for controlling a heating, ventilation, air conditioning (HVAC) system, comprising the steps:

determining a travel time from each of a plurality of mobile sites to a fixed site;

determining a conditioning time for a HVAC system at the fixed site;

turning the HVAC system ON when any of the travel times is less than the conditioning time;

turning the HVAC system OFF when all of the travel times are greater than the conditioning time plus a threshold time, wherein the conditioning time is determined using a building thermal model, and wherein the steps are performed in a processor;

wherein each mobile site communicates a separate travel time to the fixed site;

wherein the fixed site calculates a separate conditioning time, and the HVAC system uses separate threshold times for occupants sharing a same environment; and

wherein each mobile site includes a mobile transceiver and a mobile locator, and wherein the fixed site includes the processor and a fixed transceiver for communicating with each mobile site via a network.

2. The method of claim 1, wherein the mobile locator is a global positioning system.

3. The method of claim 1, wherein the mobile locator is a mobile telephone, and a location of the mobile site is provided by a mobile telephone service provider.

4. The method of claim 1, wherein the travel time is determined from locations of the mobile site,

5. The method of claim 1, wherein the travel time depends on traffic and weather conditions.

6. The method of claim 1, wherein. the travel. time is based on probabilistic. information obtained from previous traveling patterns, and considers a mode of travel, time of day, date, and day of week.

7. The method of claim 1, wherein the travel time is determined based on schedules of public transportation.

8. The method of claim 1, wherein the travel time is determined at either the fixed site or the mobile site.

9. The method of claim 1, wherein the travel time is transmitted to the fixed site periodically.

10. The method of claim 1, wherein the travel time is transmitted at a request by either the fixed site or the mobile site.

11. The method of claim 1, wherein the conditioning time is constant.

12. The method of claim 1, wherein the conditioning time is adjusted for diurnal and annual variations, and according weather forecasts.

13. The method of claim 1, wherein the conditioning time is adjusted for internal environmental conditions at the fixed site.

14. The method of claim 1, wherein the conditioning time maximizes performance of the HVAC system.

15. The method of claim 1, where the conditioning time is approximately proportional to the travel time.

16. The method of claim 1, in which the fixed site estimates a separate conditioning time for each mobile site.

17. The method of claim 1, wherein the conditioning time is slowly varying.

18. The method of claim 1, wherein the model considers thermal gain and transmission through windows, convection and conduction, shading and insulation.

19. The method of claim 18, wherein the conditioning time satisfies a thermal property constraint.