Patent ID: 8224490

Claim:
A system for controlling the heating of a plurality of individual housing units in a building, the system comprising: at least one heating unit contained in each individual housing unit for heating said individual housing unit; a relay coupled to each heating unit for turning the heating unit on and off; a control unit coupled to each of the relays, the control unit configured to cause the relays to turn their respective heating units on and off at a duty cycle by applying the duty cycle to the relays; at least one outside temperature sensor coupled to the control unit for measuring the temperature of the air outside the building; the control unit having an algorithm configured to decrease the duty cycle on each relay when the temperature of the air outside the building increases beyond a predefined minimum outside temperature; the control unit being configured to simultaneously apply different duty cycles to different relays, and, the algorithm being further configured to change the duty cycle on some of the relays more than on other of the relays depending on the temperature of the air outside the building.