Abstract: The present invention is directed to monitoring/alert systems, devices, and methods useable with animal housing units. Embodiments include a primary component, such as a system controller device, for monitoring maintenance and operational events in a housing unit and a secondary component, such as a environmental monitoring device for analyzing environmental conditions. For example, the system controller device monitors unit functions (e.g., relating to power, pre-filter(s), filter(s), fan(s), air pressure, air temperature, electrical connections, etc.) and causes alert(s) to be sent (e.g., via email or text message) if there is a malfunction or abnormal operational data. The environmental monitoring device collects environmental data (e.g., time, temperature, humidity, light, sound, carbon dioxide levels, or ammonia levels) and causes alert(s) to be sent if an abnormal environmental condition is detected.