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

2019冠状病毒病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率和确保安全重返工作岗位策略方面受到的限制。呼出的二氧化碳对人体健康的影响低至1,000 ppm，通常在拥挤、通风不良的房间中观察到。许多国家已经或正在设定最大允许接触限值。COVID-19缓解策略还提到改善通风，定期将室内空气与新鲜的室外空气交换，作为减少室内空气传播病毒的关键。虽然先进的通风系统可以自动管理室内空气质量，但显然有机会开发基于CO2监测的经济实惠的技术解决方案，以支持尽可能广泛的用户改善通风。通过引入更高效的通风控制方案，该方案可进行改造，安装和拥有成本低于竞争方案，从而降低运营成本（例如能源使用和系统维护），从而明显缓解了Covid-19的经济影响。该项目开发了一种超越当前最先进水平的自主原型无线通信自供电CO2传感器设备，以实现有效的通风控制。结合GSS的新型超低功耗N2 CO2传感器，LoRa无线通信和Lightricity世界领先的室内光伏沿着更多传感器（温度/湿度/压力/光-用于进一步的室内空气质量信息和设备管理）在一个封装将提供世界上第一个真正的自供电长，用于通风控制和占用确定的无线CO2传感器节点。每个建筑物只有一个网关和长无线范围（km），与SoA短距离无线方法（Wifi，BLE，EnOcean）相比，LoRa广域网节省了每个建筑物多个网关的部署成本，使安装，维护更加容易，并为不同类型的用户提供更好的负担能力，例如个人，住房协会，养老院。它能够经济地对控制或调整通知进行适应性和遗忘性的改造/升级，并允许护理院和住宅用户在空气质量指示通风不足时被通知进行简单实用的操作，例如打开窗户。该项目建立在以前的可行性工作的基础上，使用Lightricity PV为短距离CO2无线传感器供电，并大大扩展了无线CO2传感器的功能和能力，通过更好的通风控制减少浪费能源，并使用可再生能源（PV）避免电池浪费对环境的影响，该解决方案是可持续的。它还具有包容性，为尽可能广泛的用户提供通风控制选项，从而促进健康。

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.