This study proposes a switch-based robot interface designed to support user-centered indoor environmental control. This interface uses a large language model to initiate empathic communication, explanation of suggestions, and active interaction with the user. The system was developed to reinforce four psychological factors: explainability, empathy, proactivity, and maintaining user autonomy, with the goal of promoting user-centered support and active user engagement. First, an online survey was conducted to examine whether including explanations and empathetic expressions in robot recommendations affected user perceptions. The results showed that conditions featuring explanations and empathy garnered higher ratings for user-centered support than those providing only straightforward recommendations. Subsequently, a field experiment was conducted in an accommodation facility to assess the robot’s ability to encourage active engagement among guests in controlling indoor environments. Compared to a standard tablet interface, the proposed robot interface prompted significantly more scene-control actions. Moreover, it was shown that a high proportion (85.7%) of guests accepted the robot’s recommendations. Overall, the results indicate that integrating empathetic communication, explainability, and proactive interactions within a physical-robot interface can promote the effect of feeling user-centered support and encourage more proactivity in indoor environment control.