Abstract: A system for submetering artificial energy consumption in a multi-user environment in which a single central system source services the several separate users by means of individual space conditioning subsystems is disclosed which enables accurate proportioning of subsystem energy consumption by monitoring the time intervals of the OFF/ON status of each individual space conditioning subsystem along with the temperature of the conditioned space and utilizes the monitored time intervals and temperature in conjunction with the relative heat capacity of each individual conditioned space to determine the heat consumption of each subsystem relative to all the subsystems served by the central source.