Z-wave based zoning sensor for smart thermostats

Abstract

Background/Objectives: This paper speaks about the design of a wireless sensor module that senses the temperature and humidity of a residential building. In most of the cases the temperature in a home is controlled by a single thermostat placed at a central location. Methods/Statistical Analysis: Few rooms might be hotter or cooler than the other. Hence, zoning systems are used to provide independent comfort for each zone. Each zone can have a sensor that detects the temperature and humidity of the zone. But, the current thermostats have a sensor onboard which detect temperature and humidity. Findings: This sensor output can be affected by the heat produced by other devices on the thermostat. The solution of this problem is a wireless sensor which detects the exact temperature of the zone. Based on these values the thermostat runs a predefined algorithm and maintains the required environment in each zone. On comparison with different wireless technologies like Zigbee, Wi-Fi, Bluetooth. Z-wave suits more for the above applications whose frequency is 900MHz which is different from the crowded 2.4GHz frequency band and Z-wave also has a higher range and battery life. This system has a wireless sensor module which talks to the thermostat using Z-wave wireless communication protocol. This system uses ARM based microcontroller for wireless sensor unit. The thermostat has a high end ARM based microprocessor and a display unit which shows the acquired temperature and humidity. Conclusion/Improvements: his design shows a wireless sensor module that is implemented for a single zone system. Improvement can be done on the design to develop a low power battery operated sensor module that can be implemented for a multi zone system.