Patent ID: 8086353

Claim:
A control system for controlling an indoor heating system for an indoor environment of a building in accordance with a desired indoor temperature, comprising: a sensor for detecting an outdoor temperature, a sensor for detecting a return temperature T return of a heat carrying medium circulated in a heat distribution system with a flow rate, a controller adapted to: determine a required heating power, P req , to be delivered by said heat distribution system to maintain a heating power balance according to P req =P loss −P source , where P loss is an approximation of heating power losses from said building, and includes a dynamic approximation of heating power transfer through walls of the building, based on at least said desired indoor temperature (T room ), said detected outdoor temperature (T amb ), a heat transfer coefficient of the wall (kA), and a heat capacity of the wall (Mc p ), and P source is an approximation of heating power sources external to said heating system, and based on the detected return temperature, control a combination of forward flow temperature and the flow rate so as to ensure that the distribution system delivers said required heating power.