Today’s built environments are in urgent need of more sustainability and the application of green infrastructures to complement grey ones is a viable way to achieve this goal. This study focuses on a specific type of green infrastructure applied to building envelope on the interior side of the walls. The scientific literature refers to behavior and benefits of green infrastructures for the building envelope and it is primarily concerned with outdoor applications. This research aims to increase the knowledge of indoor vertical greenery systems by investigating the physical functioning and the induced effects, mainly from the energy and air quality point of view. An experimental test was arranged for this purpose. A real-scale prototype of indoor vertical greenery system was designed and assembled at the University of Bari. This consists of a closed chamber containing ornamental evergreen plants and equipped with a data logger and several sensors for measuring and collecting data on air, soil and plants. A fan enables the air changes inside the prototype. The occurring thermal and gas exchanges are the focus of the study. Preliminary recorded data suggest that the indoor greenery is able to reduce the temperature of outlet air. Data recorded through this experimental test are useful for investigating the physics of indoor vertical greenery and increasing knowledge of it.