HVAC MONITORING METHOD AND APPARATUS

Methods and devices for detecting inefficiencies in environmental control systems and for building a model for detecting the same. The model building method may comprise: receiving training data sets for one or more environmental control systems, identifying a category for each training data set indicative of the efficiency of the environmental control system over the training time period, computing one or more numerical features for each training data set based on setpoint data and sensor data, determining a measure of dependence between the identified category and the computed one or more numerical features, and creating a model based on the determined measure of dependence. The detection method may involve receiving a monitored data set, computing numerical features for the monitored data, and assigning a category indicative of the efficiency of a monitored environmental control system based on the model and the numerical features.