An algorithm for temperature compensation in a heated greenhouse

Abstract A temperature compensation algorithm modifies the greenhouse heating setpoint depending on temperatures previously achieved. The algorithm increases the setpoint following a period when the heating is insufficient to achieve the blueprint temperature, and may also reduce the setpoint following a period of temperatures above the blueprint. The time constant used to calculate the average departure from the blueprint is long (1–10 days). Maximum compensation is obtained with a 10-day time constant. The correction applied to the blueprint varies very slowly and does not affect the rate of temperature change demanded during the dawn, evening, or dusk change over periods.