4EvAirSense: a retrofittable, self-powered and maintenance-free LoRa wireless indoor air quality sensing platform for ventilation improvement enabling safe and healthy environments

新冠肺炎的经济和社会影响明显体现在企业、学校以及各种公共和私人室内空间在占用和确保安全重返工作战略方面受到的限制。呼出的二氧化碳影响人类健康的水平低至1000ppm，通常在拥挤、通风不良的房间里观察到。许多国家已经或正在设定最大允许接触限值。新冠肺炎的缓解策略还指出，改善通风是减少室内空气病毒传播的关键。虽然复杂的通风系统可以自动管理室内空气质量，但基于二氧化碳监测的技术解决方案显然有机会开发出负担得起的技术解决方案，为尽可能广泛的用户改善通风条件。新冠肺炎还通过引入更高效的通风控制选项来降低运营成本，例如能源使用和系统维护，并且比竞争选项具有更低的安装和拥有成本。该项目开发了一个自主原型，在当前最先进的基础上进行无线通信的自供电二氧化碳传感器设备，以实现有效的通风控制。将GSS新的超低功耗NDIR二氧化碳传感器、LORA无线通信和Lightricity世界领先的室内光伏与进一步的传感器(用于进一步的室内空气质量信息和设备管理)结合在一个小型化的封装中，将提供世界上第一个真正自供电的远程无线CO2传感器节点，用于通风控制和入住率确定。与SoA短距离无线方法(Wifi、BLE、EnOcean)相比，每栋建筑只有一个网关和长无线范围(KM)，LORA广域网节省了每栋建筑多个网关的部署成本，从而使安装更加容易，为不同类型的用户，如个人、住房协会、安老院提供更好的维护和负担能力。它支持经济的一次性改造/升级控制或向设施经理发出调整通知，并允许疗养院和住宿用户获得简单、实际的操作通知，如当空气质量表明通风不足时打开窗户。该项目建立在之前使用Lightricity PV为短程二氧化碳无线传感器供电的可行性工作的基础上，并显著扩展了无线二氧化碳传感器的最先进功能和能力。该解决方案通过更好的通风控制、减少能源浪费和使用可再生能源(PV)来避免电池废物对环境的影响，是可持续的。它还包括为最广泛的用户带来通风控制选项，从而为用户带来健康。

The economic and social impact of Covid-19 is evident in the constraints placed on businesses, schools and various public and private indoor spaces with regards to occupancy and ensuring safe return-to-work strategies. Exhaled CO2 affects human health at levels as low as 1,000 ppm, commonly observed in crowded, poorly ventilated rooms. Many countries have or are setting maximum Permissible Exposure Limits. Covid-19 mitigation strategies also cite improved ventilation, regularly exchanging indoor air with fresh outdoor air, as key to reducing indoor airborne virus transmission.Whilst the sophisticated ventilation systems can automatically manage IAQ, there is a clear opportunity to develop affordable technical solutions based on CO2 monitoring that support improvements to ventilation for the widest possible range of users. There is also clear Covid-19 economic impact mitigation in reducing the operating costs e.g. energy usage and system maintenance, by introducing more efficient ventilation control options that are retrofittable and have lower cost of installation and ownership than competing options.This project develops an autonomous prototype wirelessly communicating self-powered CO2 sensor device beyond current state-of-the-art to enable effective ventilation control. Combining GSS's new ultra-low power NDIR CO2 sensor, LoRa wireless communication and Lightricity world-leading indoor PV along with further sensors (Temperature/Humidity/Pressure/Light -- for further IAQ information and device management) in a miniaturised package would deliver the world's first truly self-powered long-range wireless CO2 sensor nodes for ventilation control and occupancy determination.With only one gateway per building and long wireless range (km), LoRa Wide Area Network saves the deployment cost of multiple gateways per building compared with SoA short-range wireless approaches (Wifi, BLE, EnOcean) enabling much easier installation, maintenance and better affordability to different types of users e.g. individuals, housing associations, residential care homes. It enables economic fit-and-forget retrofitting/upgrading of control or adjustment notification to facilities managers and allows care home and residential users to be notified for simple, practical actions like opening windows when air quality indicates insufficient ventilation. The project builds upon previous feasibility work powering a short-range CO2 wireless sensor using Lightricity PV and significantly extends functionality and capability beyond the state-of-the-art in wireless CO2 sensors.The solution is sustainable through better ventilation control reducing wasted energy and using a renewable energy source (PV) to avoid environmental impact of battery waste. It is also inclusive in bringing ventilation control options and therefore health to the widest possible range of users.