VENTILATION CONTROL APPARATUS AND METHOD

20160143181

14/946055

November 19, 2015

An environmental control system for a telecom shelter integrates with a native HVAC system for exchanging interior air in a conditioned space in a machine room, telecom enclosure, or other closed machine environment by forcing or directing cooler outside air to replace interior air without active refrigeration by the native HVAC system. Primary cooling and heating of the conditioned space in the enclosure is performed by an exchange system and control logic that identifies, based on sensory input, when outside air exchange is more efficient than native AC (Air Conditioner) operation. The native AC system is suppressed or inhibited, and primary environmental control performed by fan driven exchange of outside air with air in the enclosure. Sensors and timers identify appropriate periods to defer control to the native AC system for cooling demand in excess of outside air exchange capability, and also identify ongoing suppression, or “takeback” of cooling control from the native system when erroneous, erratic or mistaken operation results in excessive or insufficient cooling, resulting from such factors as equipment failure, operator error, and environmental/disaster occurrences.

1. A method of managing cooling resources for electronic equipment comprising: identifying a thermostatic control to a native cooling resource directed to a telecommunication equipment enclosure; interfacing with the thermostatic control for superseding the thermostatic control to enable and disable the cooling resource according to air exchange logic; disabling, based on an interior temperature of the equipment enclosure and an ambient temperature outside the equipment enclosure, the native cooling resource in favor of ambient air exchange with the equipment enclosure; and monitoring the interior temperature for determining when to re-enable the native cooling resource.

2. The method of claim 1 further comprising, upon disabling the native cooling resource, setting an override timer; evaluating, upon expiration of the override timer, continued suppression of the native cooling resource; determining, with the air exchange logic, whether the native cooling resource should be re-enabled to maintain adequate temperatures in the equipment enclosure; and enabling the native cooling resource.

3. The method of claim 2 further comprising, upon re-enabling the native cooling resource, setting a takeback timer for reevaluating continued performance of the native cooling resource; disabling, if a condition resulting in the previous disabling of the native cooling resource persists, the native cooling resource; and continuing management of the interior temperature using the ambient air exchange.

4. The method of claim 1 further comprising determining adequate temperatures defined by a range between a maximum set point and a minimum set point, and monitoring includes a measurement of an interior temperature inside the machine room, a measurement of exterior temperature of ambient air outside the machine room, and a correction interval for permitting the native control to remain idle.

5. In a machine room enclosure containing electronic equipment conditioned by a native environmental control system for maintaining temperature, a method for operating the native control system, comprising: determining when the native control is operating outside of predetermined limits for temperature; suspending operation of the native control in favor of ambient air circulation by exchanging outside air; concluding that the native control is capable of again maintaining the temperature within the predetermined limits; re-enabling the native control; and monitoring the temperature in the machine room for deviation from the predetermined limits.

6. The method of claim 5 further comprising: setting an override timer corresponding to a condition resulting in a deviant parameter associated with the operation outside of the predetermined limits of native control operation; inhibiting operation of the native control for the duration of the override timer; and enabling the native control upon expiration of the override timer based on observed correction of the deviant parameter.

7. The method of claim 5 wherein concluding capability of the native control further comprises: comparing the temperature of ambient air outside the machine room with a maximum interior temperature; and determining that ambient air circulation provides insufficient cooling capacity.

8. The method of claim 5 wherein determining operation outside of predetermined limits comprises: setting a takeback timer corresponding to a condition resulting in observed diminished performance; permitting operation of the native control for the duration of the takeback timer to ascertain if the condition causing the diminished performance has abated; and re-inhibiting the native control at the expiration of the takeback timer if the condition persists.

9. The method of claim 8 wherein determining when the native control is outside the predetermined limits further comprises: comparing the temperature of the machine room resulting from the native control to a minimum interior temperature; and determining a cooling effect from the native control is in excess of a need for maintaining the minimum interior temperature.

10. The method of claim 5 wherein suspending operation of the native control includes interfacing with a thermostatic circuit for overriding a thermostatic switch to disable the native control.

11. The method of claim 6 further comprising: identifying a short cycling and overcooling condition in the enclosure based on a plurality of occurrences of operation outside of the predetermined limits for temperature, and setting the override timer based on a duration for allowing ambient air circulation to maintain the temperature in the enclosure below a maximum set point without power cycling a compressor in the native control.

12. The method of claim 6 wherein the predetermined limits pertain to environmental conditions in the enclosure and the deviant parameter includes at least one of excessively cold interior temperature, excessive humidity, airflow or excessive cycling of a refrigerant compressor of the native control.

13. The method of claim 6 further comprising identifying a high set point defining a temperature at which the native control is invoked for cooling the machine room; identifying a low set point defining a temperature at which the native control is disabled, the high set point and low set point identifying a range of operation included in the predetermined limits for ambient air circulation in favor of native control.

14. The method of claim 5 wherein the native control includes a plurality of independently switchable compressors, and suspending operation includes: identifying a power cycle count and an elapsed time count for each of the plurality of compressors; and alternating enablement of each compressor of the plurality of compressors for achieving an even distribution of operational time.

15. The method of claim 14 further comprising receiving, from each of the plurality of compressors, an aggregated rectified signal over a single conductor, each compressor connected to a separate rectifier for providing a different waveform than the others of the plurality of compressors.

16. The method of claim 5 further comprising: performing hysteresis analysis of power cycles and elapsed time during each power cycle; concluding a short cycling pattern is causing operation outside of the predetermined limits by a disproportionate cooling effect from the elapsed time; and inhibiting operation of the native control for extending a cycle time without deviation from the predetermined limits of temperature.

17. An air exchange controller device for a telecom shelter, comprising: An interface to a thermostatic control of a native cooling resource directed to a telecommunication equipment enclosure, the interface adapted to supersede the thermostatic control to enable and disable the cooling resource according to air exchange logic in a controller; the air exchange logic operable to disable, based on an interior temperature of the equipment enclosure and an ambient temperature outside the equipment enclosure, the native cooling resource in favor of ambient air exchange with the equipment enclosure; and an override timer for setting a duration of disabling of the native cooling resource, the air exchange logic further operable to monitor the interior temperature for determining when to re-enable the native cooling resource.

18. The device of claim 17 wherein the air exchange logic is further operable to set the override timer and evaluate, upon expiration of the override timer, continued suppression of the native cooling resource; the air exchange logic configured to determine, with the air exchange logic, whether the native cooling resource should be re-enabled to maintain adequate temperatures in the equipment enclosure and to enable the native cooling resource by directing the interface to the thermostatic control.

19. The device of claim 18 further comprising a takeback timer in the controller, the takeback timer responsive to the air exchange logic for, upon re-enabling the native cooling resource, setting the takeback timer until reevaluation of continued performance of the native cooling resource; the air exchange logic configured to disable, if a condition resulting in the previous disabling of the native cooling resource persists, the native cooling resource, and to continue management of the interior temperature using the ambient air exchange.

20. The device of claim 18 further comprising a sensor indicative of a deviant parameter, the air exchange logic further operable to: set an override timer corresponding to a condition resulting in the deviant parameter associated with the operation outside of the predetermined limits of native control operation; inhibit operation of the native control for the duration of the override timer; and enabling the native control upon expiration of the override timer based on observed correction of the deviant parameter.

21. The device of claim 17 wherein the interface for suspending operation of the native control includes an interface with a thermostatic circuit for overriding a thermostatic switch to disable the native control and a rectified connection to the thermostatic circuit for determining when the thermostatic circuit is energized, the rectified connection varying a response based on the thermostatic circuit.

22. A computer program product on a non-transitory computer readable storage medium having instructions that, when executed by a processor, perform a method for temperature monitoring and control, the method comprising: determining when a native control is operating outside of predetermined limits for temperature; suspending operation of the native control in favor of ambient air circulation by exchanging outside air; concluding that the native control is capable of again maintaining the temperature within the predetermined limits; re-enabling the native control; and monitoring the temperature in the machine room for deviation from the predetermined limits.

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