Method of maximizing the efficiency of an environmental control system including a programmable thermostat

Claim 2

The process by which a programmable thermostat of an environmental control system having a mode of operation for controlling the temperature of an area defined by a structure having a thermal mass and a variable external environment conserves energy, said thermostat having an occupied set point temperature and an occupied set point time, the time at which the occupied set point temperature becomes effective, and an unoccupied set point temperature and an unoccupied set point time, the time at which the unoccupied set point temperature becomes effective; comprising the steps of: a) determining if the next set point temperature is an unoccupied set point temperature; b) when step a is true, advancing the unoccupied set point time by an amount Δt, where Δt is a function of the thermal mass of the structure defining said area, and the structure's external environment; c) calculating a value for Δt each time step b, is executed by determining the time it takes for the temperature of the area defined by the structure to change from the occupied set point temperature to a temperature a given number of degrees closer to the unoccupied set point temperature; d) using the value of Δt calculated in step c, the next time the process is executed; and e) periodically repeating steps a through d.

Claim 3

The process of claim 1 in which the mode of operation of the environmental control system is a heating mode.

Claim 4

The process of claim 2 in which maximum and minimum values for Δt are established.

Claim 5

The process of claim 1 in which the mode of operation of the environmental control system is a cooling mode.

Claim 6

The process of claim 4 in which maximum and minimum values for Δt are established.

Claim 7

The process by which a programmable thermostat advances by a time period, Δt, the time at which an unoccupied set point temperature (un-SP-T°), following an occupied set point temperature (oc-SP-T°) becomes effective where the magnitude of Δt is a function of a structure's thermal characteristics and the structure's external environment comprising the steps of: a) periodically determining if an (un-SP-T°) follows an (oc-SP-T°); b) if step a is not true, terminating the process; c) if step a, is true, determining if the current time (cur-t) is greater the unoccupied set point time (un-SP-t) minus Δt; d) if step c is not true, terminating the process; e) if step c is true, setting the temperature (of oc-SP-T°) equal to that of a last set point temperature (las-SP-T°) and the (oc-SP-T°) equal to that of the (un-SP-T°) and determining if the equation: Δt+(cur-t)-(un-SP-t)>maxΔt is true or false, where maxΔt is the maximum permitted value of Δt; f) if step e is true, the value of Δt is made equal to that of max Δt and the process is terminated; g) if step e is false, determining if: (cur-T°)-(oc-SP-T°)<maxΔT°; is true or false, where maxΔT° is the maximum desired temperature deviation from the (cur-SP-T°) occurring during the time period Δt; h) If step g is true, repeat steps e, and g until step e becomes true, or step g becomes false, which ever first occurs; i) if step g becomes false before step e becomes true, determining if the equation: Δt+(cur-t)-(oc-SP-t)<(minΔt) is true or false, where minΔt is the minimum magnitude that Δt is permitted to have; j) if step i is true, the magnitude of Δt is made equal to that of minΔt and the process is terminated; and k) if step i is false, change the value of Δt to equal: Δt+(cur-t)-(nex-SP-t) and terminate the process.

Claim 8

The process by which a programmable thermostat advances by a time period, Δt, the time at which an unoccupied set point temperature (un-SP-T°), following an occupied set point temperature (oc-SP-T°) becomes effective where the magnitude of Δt is a function of a structure's thermal characteristics and the structure's external environment comprising the steps of: a) periodically determining if an (un-SP-T°) follows an (oc-SP-T°); b) if step a is not true, terminating the process; c) if step a, is true, determining if the current time (cur-t) is greater the unoccupied set point time (un-SP-t) minus Δt; d) if step c is not true, terminating the process; e) if step c is true, setting the temperature (of oc-SP-T°) equal to that of a last set point temperature (las-SP-T°) and the (oc-SP-T°) equal to that of the (un-SP-T°) and determining if the equation: Δt+(cur-t)-(un-SP-t)>maxΔt is true or false, where maxΔt is the maximum permitted value of Δt; f) if step e is true, the value of Δt is made equal to that of max Δt and the process is terminated; g) if step e is false, determining if: (cur-T°)-(oc-SP-T°)<maxΔT°; is true or false, where maxΔT° is the maximum desired temperature deviation from the (cur-SP-T°) occurring during the time period Δt; h) If step g is true, repeat steps e, and g until step e becomes true, or step g becomes false, which ever first occurs; i) if step g becomes false before step e becomes true, determining if the equation: Δt+(cur-t)-(oc-SP-t)<(minΔt) is true or false, where minΔt is the minimum magnitude that Δt is permitted to have; j) if step i is true, the magnitude of Δt is made equal to that of minΔt and the process is terminated; and k) if step i is false, change the value of Δt to equal: Δt+(cur-t)-(nex-SP-t) and terminate the process.

Claim 9

The program of claim 6 in which the unoccupied set point temperature is lower than the occupied set point temperature.

Claim 10

The program of claim 6 in which the unoccupied set point temperature is higher than the occupied set point temperature.