A summative user evaluation of connected thermostats

Abstract

Thermostats are the nexus of human comfort within buildings. However, the building industry has prioritized a “product-centered” approach over a “human-centered” approach when developing thermostats. As technology advances, we have seen a proliferation of connected thermostats developed to provide a more convenient way to manage thermal comfort. However, if connected thermostats are not designed based on user needs, their benefits will not be fully realized. To understand how connected thermostats meet or do not meet user needs, this summative evaluation study employed text-mining of 130,237 user reviews from Amazon (n = 35,275), and Apple App Store (n = 94,962) to systematically evaluate users' perception of 52 connected thermostats and their 37 associated iOS apps using a grounded theory approach. The analysis revealed emergent themes from Amazon reviews, including “usability,” “functionality,” “user support,” “connection and compatibility” “overall impression,” and “cost and value”. Similarly, Apple App Store reviews highlighted the themes “usability,” “functionality,” “update and maintenance,” “reliability and performance,” “overall impression,” and “user support” in order of their importance. Usability emerged as the most frequent and important theme in both Amazon and Apple App Store reviews, highlighting the role of human-technology interactions. While users extensively discussed concepts like “ease” and “comfort,” “energy” was not as prominently featured. In addition, the analysis found that “usage data privacy” was a significant concern for users. This study's approach can be employed to enhance human factors knowledge in connected building interface design, and this methodological approach could be an effective supplement for other human-building product evaluations.