Fault tolerant environmental monitoring systems employing WiFi and cellular technology in combination with cloud based data logging and alert services

摘要

Traditional building energy and HVAC system monitoring has been installed for years with good success. Established approaches employ chart recorders, stand alone data loggers, and hard wired alarm systems to assist building managers optimize the performance of their systems, diagnose potential problems, and alert them when things go wrong. In some cases these devices are tied to building computer networks, and the network is used to report and send alert or alarm messages when necessary. In today's environment of fully taxed power, energy and HVAC systems, it has become more and more common that when problems occur, network communications can also be affected. Monitoring systems backed with 24/7 staffing can be alerted when systems go offline, however the cost of such monitoring is not something many small and mid-sized businesses can afford, particularly in today's economically challenging times. This paper discusses options for low cost, fault tolerant, cloud based approaches to environmental monitoring. With sensor networks connected to secure, reliable cloud servers, fault tolerant alerting algorithms can be and have been developed to insure that when problems occur, those responsible to respond are notified. And with the addition of cost effective cellular communication technology, fault tolerant networks independent of building networks can provide a greater range of options for secure, reliable building and energy management as well as emergency response when needed. Case studies of two such installations, one using wireless devices connected to the site's computer network and one using cellular technology, are presented to compare the operational differences and benefits of each approach.