Environment Sensor Node Design for Building Energy Management Systems (BEMS)

This paper presents the design of a Sensor Node for sensing environmental variables in Buildings with the objective to control HVAC (Heating, Ventilation and Air Conditioning) system using a BEMS (Building Energy Management Systems) to achieve energy savings. BEMS is a control system used to manage the energy consumption of a Building trying to achieve energy savings. The designed Sensor Node is capable of measure six different environmental variables: temperature, humidity, and carbon dioxide, using a Sensirion SCD30 sensor; particulate matter 2.5, and 10, using a Sensirion SPS30 sensor, and lighting using a BH1750FVI sensor. The control unit for the Sensor Node is designed using a node MCU ESP8266 microprocessor which is capable to receive the sensors signals. The microprocessor are connected to a XBEE module for communications purpose with a main control system. The main control system is developed in a Raspberry Pi. The objective of this design is control the set point of the HVAC equipment using the values of the sensed environmental variables. The main contribution of this work is to control wirelessly the operation of the HVAC equipment through the set point for a determinate space using the environmental sensor node measures obtained of the space to be controlled.