Temperature compensation method for thermostats

• US 8,695,887 B2
• Filed: 03/06/2007
• Issued: 04/15/2014
• Est. Priority Date: 03/06/2007
• Status: Active Grant

• Current Assignee: Trane International Inc. (Trane Technologies plc)
• Original Assignee: Trane International Inc. (Trane Technologies plc)
• Inventors: Helt, Robert W., Filbeck, Amanda
• Primary Examiner(s): Elve, Alexandra
• Assistant Examiner(s): Comings, Daniel C
• Application Number:
  US11/714,616
• Publication Number:
  US 20080217418A1
• Time in Patent Office: 2,597 Days
• Field of Search: 236/1.B, 236/1.C, 236/91.R, 236/91.D, 165/211, 700/277, 700/278
• US Class Current: 236/1.C
• CPC Class Codes: G05D 23/1931 to control the temperature of one space

Abstract

An air conditioning control system and method for compensating for heat gain or loss in an air conditioned space due to window area and temperature differential between outdoor temperature and indoor temperature. For predetermined amounts of window area, as a percent of total wall area defining an enclosed space, the thermostat setpoint or measured temperature is adjusted as a function of the temperature differential between the enclosed space and the outdoor ambient temperature, for example. Data may be accumulated and stored in a controller memory for various types of structures and rates of heat transfer therethrough for various amounts and type of window area as a percent of the total wall area, for example.

Claims

1. In an air conditioning system for providing conditioned air to an enclosed space, a method for compensating for a temperature differential between an outdoor temperature and an indoor temperature of the enclosed space having a predetermined amount of window or glass wall area as a percentage of a total wall area defining said enclosed space exposed to said outdoor temperature, said system including a thermostat including a microcontroller, an indoor temperature sensor for measuring the indoor temperature and an outdoor temperature sensor for measuring the outdoor temperature that is exposed to a structure defining said enclosed space, said method comprising:

determining the amount of window area or glass as a percentage of the total wall area defining said enclosed space;

determining the temperature differential between the indoor temperature of the enclosed space and the outdoor temperature exposed to the structure defining said enclosed space;

adjusting one of said measured indoor temperature and a setpoint temperature of said thermostat by a predetermined offset dependent on said differential temperature and said window area; and

measuring a rate of change of the temperature differential between the indoor temperature and the outdoor temperature and adjusting said offset dependent on said rate of change of the temperature differential.

2. The method set forth in claim 1 including:

providing a memory for storing data related to temperature differentials between said indoor temperature and said outdoor temperature and the amount of window area as a percent of total wall area defining said enclosed space for selected amounts of window area.

3. The method set forth in claim 1 including the step of:

allowing the indoor temperature to increase a predetermined amount dependent on the temperature differential between the indoor temperature and the outdoor temperature if heat is being radiated through said window area.

4. In an air conditioning system for providing conditioned air to an enclosed space;

a thermostat;

an indoor temperature sensor for measuring a temperature in said enclosed space;

an outdoor temperature sensor for measuring an outdoor temperature exposed to a structure defining said enclosed space;

a microcontroller operably associated with said thermostat and said sensors, said microcontroller including;

a database operably associated with said microcontroller including, for a given enclosed space, a percent of total wall area defining said enclosed space comprising window or glass wall area;

means for determining a temperature differential between the temperature of said enclosed space and the outdoor temperature, essentially surrounding said enclosed space;

means for adjusting one of the temperature measured in said enclosed space and a setpoint temperature of said thermostat by a predetermined offset temperature value dependent on said temperature differential and said window area; and

means associated with said microcontroller for measuring a rate of change of said temperature differential between said temperature in said enclosed space and said outdoor temperature and adjusting said offset temperature value in response to said measured rate of change of said temperature differential.

5. The system set forth in claim 4 including:

a memory associated with said microcontroller for storing data related to said temperature differential between said indoor temperature and said outdoor temperature and the amount of window area as a percent of total wall area defining said enclosed space for selected amounts of window area.

6. In an air conditioning system for providing conditioned air to an enclosed space, a method for compensating for a temperature differential between an outdoor temperature and an indoor temperature of an enclosed spaces having a predetermined amount of an area of a predetermined heat loss rate as a percentage of a total wall area exposed to said outdoor temperature, said system including a thermostat including a microcontroller, an indoor temperature sensor for measuring the temperature in said enclosed space and an outdoor temperature sensor for measuring the outdoor temperature exposed to structure defining said enclosed space, said method comprising:

determining the amount of said area of predetermined heat loss rate as a percentage of the total wall area defining said enclosed space;

determining the temperature differential between the indoor temperature in said enclosed space and the outdoor temperature of the environment, essentially surrounding said enclosed space;

adjusting one of said measured temperatures and a setpoint temperature of said thermostat by a predetermined offset temperature value dependent on said temperature differential and said area of predetermined heat loss rate;

measuring a rate of change of the temperature differential between said indoor temperature in said enclosed space and said outdoor temperature and adjusting the offset temperature value in response to said measured rate of change of the temperature differential.

7. The method set forth in claim 6 including:

providing a memory for storing data related to temperature differential between said indoor temperature and said outdoor temperature and said area of predetermined heat loss rate as a percent of total wall area defining said enclosed space for selected amounts of said area of predetermined heat loss rate.

8. The method set forth in claim 6 including the step of:

allowing said indoor temperature to increase or decrease a predetermined amount dependent on said temperature differential between said indoor temperature and said outdoor temperature if heat is being radiated through said area of predetermined heat loss rate.