1. A system for controlling a climate control unit, comprising: a 2D monocular camera; a processor, connected to an output of the camera, wherein the processor is configured to construct a background model and foreground models of an environment from images acquired of the environment by the camera, wherein the background model represents the environment when unoccupied, and there is one foreground model for each person in the environment, and a 2D location of each person is determined from the background and foreground models, and a 3D location of each person is determined from the estimated 2D location and inferences made from the images; and a controller configured to generate a control signal for the climate control unit based on the 3D locations.