Patents by Inventor Eric W. Grald

Eric W. Grald has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5351855
    Abstract: An environmental control system that utilizes the output of a thermostat to estimate the outdoor temperature can be used to eliminate the possibility of condensation on the inside of windows and on the inside of the walls. This is important in homes and buildings that are located in areas where the outdoor temperature gets very low. An acceptable humidity level can be calculated when the outdoor temperature has been determined. Once the acceptable humidity level is calculated, this value can be communicated to the humidistat so the humidity level within the house can then be adjusted accordingly. The humidistat can have the capability to manually override the automatic adjustments, thus giving the operator the flexibility of maintaining the humidity level within the building at a desired level.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: October 4, 1994
    Assignee: Honeywell Inc.
    Inventors: Lorne W. Nelson, Eric W. Grald
  • Patent number: 5318104
    Abstract: The present invention describes an apparatus and method for controlling the temperature in a plurality of comfort zones within a house or building. The invention contemplates a series of zone control devices which are selectively opened or closed to allow heating and/or cooling to individual zones. The temperature in each zone is sensed and compared to a preferred setpoint temperature to determine a temperature error for each zone. The respective temperature error signals for each zone are used to determine the zone of greatest thermal error. The zone of greatest thermal error is used to turn the heating/cooling plant on and off. The remaining zone or zones of lesser thermal error have their zone control devices closed or opened, depending upon the temperature error signal for their respective zones. In this manner, all zones are synchronized to the zone of greatest thermal error and to the cycle of the heating/cooling plant.
    Type: Grant
    Filed: September 16, 1992
    Date of Patent: June 7, 1994
    Assignee: Honeywell Inc.
    Inventors: Dipak J. Shah, J. Ward MacArthur, Robert L. Buchholz, Eric W. Grald, Lorne W. Nelson
  • Patent number: 5115968
    Abstract: A temperature control system has a thermostat which provides an on/off signal. The on/off signal has an on period and an off period and is indicative of a temperature error. The temperature control system is suitable for controlling temperature control equipment. The on/off signal is sensed and the temperature error is determined based on the on/off signal. The temperature control system is controlled based on the temperature error determined.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: May 26, 1992
    Assignee: Honeywell Inc.
    Inventor: Eric W. Grald
  • Patent number: 5024265
    Abstract: A zone control system uses signals from a plurality of separate zone thermostats to determine the zone of greatest thermal load or demand. Specifically, the on-time of each thermostat signal is integrated with respect to time so that the zone of greatest demand can be determined. The thermostat signal from the zone of greatest demand is used to control a duct damper between that zone and a heating/cooling plant. To synchronize the opening of the other zone duct dampers with the duct damper of the zone of greatest demand, the length of each of the on-periods of the thermostats in the other zones is first converted to the cycle rate of the zone of greatest demand thermostat since the other thermostats are operating at different duty cycles. A microprocessor-based master zone controller uses these converted on-signals to control respective zone duct dampers in the other zones coincident with the start of the thermostat on-period of the zone of greatest demand.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: June 18, 1991
    Assignee: Honeywell Inc.
    Inventors: Robert L. Buchholz, Eric W. Grald, Lorne W. Nelson, Dipak J. Shah
  • Patent number: 4901918
    Abstract: An adaptive cycle rate thermostat control. A thermostat including a switch and apparatus for heat anticipation operates responsively to an anticipator time constant. Apparatus for sensing room temperature provides an electronic signal proportional to the room temperature sensed. Apparatus for providing an acitivation signal to the switch responsive to the heat anticipation apparatus and sensed temperature cycles a variable-speed heat pump. Apparatus for modifying the anticipator time constant in response to room temperature swings provides the modified anticipator time constant to the heat anticipation means so as to keep room temperature swings within desirable limits while operating the heat pump more efficiently.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: February 20, 1990
    Assignee: Gas Research Institute
    Inventors: Eric W. Grald, J. Ward MacArthur
  • Patent number: 4889280
    Abstract: An acutioneering control adapted to be connected to a thermostat control for temperature modifying apparatus wherein the thermostat control includes a temperature sensor which provides a sensed temperature signal. The auctioneering control includes apparatus for sensing absolute humidity and providing a first output signal corresponding to the sensed absolute humidity; first apparatus for comparing the sensed absolute humidity with a predetermined value wherein the first comparing apparatus receives the first output signal and provides a humidity error signal; apparatus for modifying a predetermined temperature setpoint signal responsive to the humidity error signal; apparatus for limiting the modified temperature and providing a limited temperature setpoint signal; and second apparatus for comparing the limited temperature setpoint signal with the sensed temperature signal.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: December 26, 1989
    Assignee: Gas Research Institute
    Inventors: Eric W. Grald, J. Ward MacArthur
  • Patent number: 4873649
    Abstract: A controller and a related method that maintains thermal comfort in an occupied space at a user-defined level while simultaneously maximizing the efficiency of the space conditioning equipment. The controller determines the setting of heating/cooling capacity, indoor airflow rate, evaporator superheat and other system parameters such that a comfort constraint is satisfied. The comfort index may be any arbitrarily-defined relationship of measured or inferred quantities such as air temperature, relative humidity, air velocity, mean radiant temperature, CO.sub.2 concentration, etc. The controller ensures that the error between comfort index and the comfort setpoint is zero while the energy consumed by the space conditioning equipment is minimized.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: October 10, 1989
    Assignee: Honeywell Inc.
    Inventors: Eric W. Grald, J. Ward MacArthur