Title
Inferring Smart Schedules for Dumb Thermostats
Abstract
Heating, ventilation, and air conditioning (HVAC) accounts for over 50% of a typical home’s energy usage. A thermostat generally controls HVAC usage in a home to ensure user comfort. In this article, we focus on making existing “dumb” programmable thermostats smart by applying energy analytics on smart meter data to infer home occupancy patterns and compute an optimized thermostat schedule. Utilities with smart meter deployments are capable of immediately applying our approach, called iProgram, to homes across their customer base. iProgram addresses new challenges in inferring home occupancy from smart meter data where (i) training data is not available and (ii) the thermostat schedule may be misaligned with occupancy, frequently resulting in high power usage during unoccupied periods. iProgram translates occupancy patterns inferred from opaque smart meter data into a custom schedule for existing types of programmable thermostats, e.g., 1-day, 7-day, and so on. We implement iProgram as a web service and show that it reduces the mismatch time between the occupancy pattern and the thermostat schedule by a median value of 44.28min (out of 100 homes) when compared to a default 8am-6pm weekday schedule, with a median deviation of 30.76min off the optimal schedule. Further, iProgram yields a daily energy savings of 0.42kWh on average across the 100 homes. Moreover, the schedules generated from iProgram converge to optimal schedules within a couple of weeks for most homes. We also show that homeowners having multiple HVAC zones can utilize iProgram and potentially increase unconditioned times of less occupied parts of their homes by 70%. Utilities may use iProgram to recommend thermostat schedules to customers and provide them estimates of potential energy savings in their energy bills.
Year
DOI
Venue
2019
10.1145/3226031
ACM Transactions on Cyber-Physical Systems
Keywords
Field
DocType
Energy efficiency, HVAC control, occupancy detection, scheduling
Air conditioning,Scheduling (computing),Efficient energy use,HVAC,Thermostat,Real-time computing,Schedule,Occupancy,Smart meter,Engineering
Journal
Volume
Issue
ISSN
3
2
2378-962X
Citations 
PageRank 
References 
0
0.34
11
Authors
6
Name
Order
Citations
PageRank
Srinivasan Iyengar1194.89
Sandeep Kalra261.14
Anushree Ghosh300.34
David E. Irwin489998.12
Prashant J. Shenoy56386521.30
Benjamin M. Marlin671.94