System and method for estimating temperature drift and drive curves

Abstract

A method for estimating temperature drift and drive curves comprises the steps of: (1) obtaining a plurality of temperature data samples over a period of time, the period of time corresponding to one of a drive operation or a drift period of an environmental control unit; (2) if the period of time corresponds to a drive operation, calculating a plurality of drive curves, each curve calculated using a different data sample subset; (3) else if the period of time corresponds to a drift period, calculating a plurality of drift curves, each curve calculated using a different data sample subset; (4) determining which curve best fits the data samples; and (5) using the best fit curve to predict one of a future temperature at a known time or a future time at which a known temperature will be reached.

Description

FIELD OF THE INVENTION[0001]This invention relates to the temperature and other climate control of interiors of buildings, and in particular to a system for controlling the temperature of an environment according to predetermined criteria including the presence or absence of people, programmable comfort ranges, and programmable time tolerances to reach those comfort ranges.BACKGROUND OF THE INVENTION[0002]In conventional temperature or climate control systems (e.g. heating, ventilating and air conditioning systems, referred to herein generally as “HVAC”), thermostats are used to control when the HVAC system turns on and off. The user presets a desired temperature (or “user set point”), and when the temperature of the controlled space is different from the preset temperature, the HVAC system heats or cools the air until the preset temperature is reached.[0003]Thus, conventional enclosed space thermostats are merely on / off switches with a sensor to measure the enclosed space temperatu...

AI Technical Summary

Benefits of technology

[0008]The object of the present invention is to overcome the aforementioned drawbacks and to provide a method and apparatus for estimating temperature drift and drive curves. The estimated curves of the present invention provide a more accurate representation of actual temperature data than the curves determined using prior methods. Therefore, the present invention provides a more accurate way of predicting a future temperature value at particular time or of predicting at which time a particular temperature value will be reached.

Problems solved by technology

A problem with such thermostats is that the temperature is maintained at the user set point whether people are present or not, using costly natural resources.

Heating or cooling when people are not present wastes a great deal of these resources.

Problems with this approach are that the programming of the clock-thermostats is troublesome, and moreover that, even when the programming is done correctly, people's schedules change and thus often do not match the preprogrammed times.

The problem with these thermostats is the second temperature is often either too far away from the first temperature to provide satisfactory comfort when someone returns to the room, or too close to the first temperature to achieve adequate energy savings.

Further, enclosed space and ambient conditions change constantly, so these thermostats are very difficult to regulate for optimal energy savings versus comfort trade-offs.

Even if a user could figure out the optimum second thermostat setting for comfort and maximum energy savings at a given time, conditions constantly change and that setting may quickly become non-optimal.

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