The article describes the results of the project “open source Smart lamp” aimed at designing and developing a smart object able to manage and control the Indoor Environmental Quality (IEQ) of the built environment. A first version of this smart object, built following a DIY approach using a microcontroller, an integrated temperature and relative humidity sensor and techniques of Additive Manufacturing, allows for the adjustment of the Indoor thermal Comfort Quality (ICQ), by interacting directly with the air conditioner. An experimental test in a real office showed how the use of the Smart Lamp effectively reduced energy consumption for air conditioning, optimizing the thermal comfort of the workers.
As it is well known, the IEQ is a holistic concept including the Indoor Air Quality (IAQ), the Indoor Lighting Quality (ILQ) and Acoustic comfort, besides the thermal comfort. The upgrade of the Smart Lamp bridges this gap providing the possibility to interact with the air ex change unit and lighting system, in order to get an overview of the potential of a nearable device in the management of the IEQ. The upgraded version was tested in an office equipped with a mechanical ventilation and air conditioning system and occupied by 4 workers. The experiment was compared with a baseline scenario and the results showed how the application of the nearable device effectively optimizes both IAQ and ILQ.
The hardware and software elements of the system are defined using typical concepts of the DIY philosophy: wireless communication, low cost hardware and 3D printed parts. The system is splitted in two parts (Figure 1): a monitoring station placed near the workstation (nearable monitoring station) able to assess the exact level of illuminance and air quality and a receiving station (actuation station) wireless connected to the nearable monitoring station that manages the actuation of both the air exchange system and the lamp.
CASE STUDY AND METHOD OF EVALUATION OF COMFORT
A carbon dioxide concentration sensor (CO2) and a lux meter (LX) were installed (Figure 2a,b) close to the work place where the air and lighting quality are analyzed. Both sensors are placed on the desktop next to the nearable and are connected to a data logger (D). The data of the environmental variables are recorded every 10 s and then averaged every minute and stored on the memory card.
The analysis of CO2 concentration (Figure 3b) shows a marked improvement after the adoption of the nearable control system: in period I, during working hours, hourly average values with maximum values close to 2000 ppm were recorded, in any case higher than the 900 ppm limit, with high range of excursion; in period II, the level of CO2 concentration in the air was maintained below the threshold value with small variations over the time.
The developed system demonstrates that a nearable system designed and implemented starting from the maker movement philosophy and DIY approach is suitable to ensure good levels of both IAQ and ILQ. The analysis conducted so far demonstrates how it is possible to optimally manage the indoor environmental comfort using some electronic components and a 3D printer. The potential of this basic device is confirmed by tests in real working conditions. The characteristics so far described and analyzed allow for a wide field of application aimed at improving users satisfaction in indoor environments.
Authors: Francesco Salamone | Lorenzo Belussi | Ludovi co Danza | Matteo Ghellere | Italo Meroni