There are many different types of smart systems that are utilized when designing Smart Home Systems today. Some smart systems include smart lighting, smart entertainment systems like smart televisions, and smart thermostats. The most prevalent and academically researched smart home system today is the smart thermostat. Research from Nest Labs shows that on average, users of its smart thermostats use 15% less energy on heating their homes and approximately 11% on cooling. Users of smart thermostats save about $140 annually.
The schools of Computer Science and Architecture at the University of Virginia did a study on energy consumption with smart thermostats. Their study was titled The Smart Thermostat: Using Occupancy Sensors to Save Energy in Homes. The objective of their study was to propose a valid solution to the problem of overusing energy with conventional heating and cooling systems. Their solution was the smart home system that “uses occupancy sensors to automatically turn off the HVAC system when the occupants are sleeping or away from home”[1]. Challenges of their solution included 1) “quickly and reliably [determining] when occupants [left] the home or [went] to sleep” and 2) “[deciding] when to turn the HVAC system back on” [1]. Their approach included comparing results from utilizing the “smart thermostat algorithm” and the “reactive algorithm”. The reactive algorithm is a methodology “that turns the system on in response to motion sensor or door sensor values, and turns the system off in response to a period of inactivity”. “Empirical measurements of the temperature response and energy consumption of a home with a typical heating system” are made using the “EnergyPlus home energy simulation framework” [1].
Data was collected using using surveys where “each individual [was] instructed to write down their sleep, wake leave, and arrive times every day” [1]. The “data was collected through periodic telephone calls [1]. They also included publicy-available home occupancy data in their analysis. In addition, simulations frameworks including the “EnergyPlus Simulator” were used to model energy consumption data of conventional heating systems in homes.
From their data collection, they accumulated results that support utilizing the smart systems. They found that using the smart thermostat can “save 28% of residential HVAC energy consumption on average, without sacrificing comfort” [1]. They anticipated “a cost of less than $10 billion in hardware to equip all 130 million homes in the U.S.” using the smart thermostat [1]. Their calculated expected savings “was estimated at 113.9 billion kWh nationwide per year” using the smart thermostat instead of conventional heating [1].
Energy saved by UC San Diego researchers using smart thermostat over the course of several months. [2]
Design and testing of a similar smart thermostat system was conducted the University of California, San Diego. Students constructed a system that detected and kept track of when certain rooms in a building were occupied, and decreased the extent to which the climate of the room was controlled while no one was present. This approach to climate control is just like that of smart thermostats you can buy for your home. Researchers found that this approach used between 10 and 15 percent less energy than conventional thermostats. [2]
Citations
[1]
Lu, J., Sookoor, T., Srinivasan, V., Gao, G., Holben, B., Stankovic, J., . . . Whitehouse, K. (2010). The Smart Thermostat: Using Occupancy Sensors to Save Energy in Homes. Retrieved October 31, 2015.
[2]
Agarwal, Y., Baji, B., Gupta, R., Lyles, J., Wei, M., & Weng, T. (2010, November 2). Occupancy-Driven Energy Management for Smart Building Automation. Retrieved October 31, 2015.