The present invention relates to thermostats and other thermal comfort controllers and particularly to a graphical user interface for such thermal comfort controllers.
Current thermal comfort controllers, or thermostats, have a limited user interface which typically includes a number of data input buttons and a small display. Hereinafter, the term thermostat will be used to reference a general comfort control device and is not to be limiting in any way. For example, in addition to traditional thermostats, the present such control device could be a humidistat or used for venting control. As is well known, thermostats often have setback capabilities which involves a programmed temperature schedule. Such a schedule is made up of a series of time-scheduled set-points. Each set-point includes a desired temperature and a desired time. Once programmed with this temperature schedule, the controller sets-up or sets-back the temperature accordingly. For example, a temperature schedule could be programmed so that in the winter months, a house is warmed to 72 degrees automatically at 6:00 a.m. when the family awakes, cools to 60 degrees during the day while the family is at work and at school, re-warms to 72 degrees at 4:00 p.m. and then cools a final time to 60 degrees after 11:00 p.m., while the family is sleeping. Such a schedule of lower temperatures during off-peak hours saves energy costs.
It is well known that users have difficulty using the current form of a user interface for thermostats because such an interface is not intuitive and is somewhat complicated to use. Therefore, users either do not utilize the energy saving programmable functions of the controller, or they do not change the schedule that is programmed by either the installer or that is the factory default setting.
Another limitation of the current user interfaces for thermostats is that once programmed, the temperature schedule cannot be easily reviewed. Usually, the display is configured to show one set-point at a time in a numerical manner. Using the input buttons, the user must ‘page forward’ to the next set-point in the schedule or ‘page backward’ to the previous set-point.
Although the user can, with difficulty, determine the temperature schedule that is programmed into the controller, the user cannot determine how closely this temperature schedule was followed. Of course, when a new set-point determines that the controller should either raise or lower the temperature in a house or other building, the temperature does not immediately change to that new temperature. It can take some time for the room or building to warm up or cool down to the desired temperature. The thermostat typically tracks this information to allow adjustment to be easily made. At present, the user has no way of viewing this information and no way of correlating the temperature schedule with actual house temperatures.
What is needed in the art is a user interface for a thermostat in which the temperature schedule is more easily programmed. The user interface should display a more user friendly representation of the schedule so that the user can review an entire day's schedule all at once. The user interface should also easily display alternative schedules, such as a weekend and weekday schedule. Further, the graphical representation should itself be the intuitive means to programming the schedule. The user interface should also be able to compare the temperature schedule against the actual historical temperature over a period of time.