Lu, J., Sookoor, T., Srinivasan, V., Gao, G., Holben, B., Stankovic, J., … & Whitehouse, K. (2010, November). The smart thermostat: using occupancy sensors to save energy in homes. In Proceedings of the 8th ACM Conference on Embedded Networked Sensor Systems (pp. 211-224). ACM.

This paper explores the concept of a smart thermostat that senses occupancy in the home. The thermostat senses occupancy statistics in the home in order to save energy through an improved control of the HVAC system.

The thermostat uses a combination of long-term occupancy and sleep patterns with real-time sensor data to control the HVAC system. The thermostats are programs to record and analyze 51 data sets, with sensors around the home collecting the wake, leave, arrival and sleep times of the occupants. The thermostat then acts as a self-regulator, knowing the occupants everyday patterns and when to turn itself on and off. After collecting data for a short period, the smart thermostat stores what the occupants like the temperature to be at, at what time, during which days. The results show that the smart thermostat can help save a lot of money in terms of energy, knowing when to turn off and on and regulate savings.

The smart thermostat has the potential for large impact because of its low cost; usually costing less than $25 per home, and can save 28% of residential HVAC energy consumption, without sacrificing comfort. Studies have shown that energy-saving technologies should produce a return on investment within two years to achieve widespread adoption. For example: In the US, the average expenditure per household for heating and cooling is $677 a year, or $56.42 a month. In order to be financially viable, the system should cost about $230, with hardware, installation, configuration, and maintenance. This article states that a smart thermostat could cost as little as $25, being easy to retrofit into existing homes and buildings. Easy changes to make to put some more cash back in your wallet.

http://dl.acm.org/citation.cfm?id=1870005