摘要 |
Environmental heating/cooling systems are controlled by an interactive microprocessor and have continuous on-time and adaptive cycling modes wherein continuous on-time brings the temperature to a programmed set point and cycling precisely maintains that temperature rather than causing the temperature to oscillate between limits of a dead zone. Minimum pause and on-time intervals of the cycling mode are established in accordance with optimum thermal transfer efficiency and/or equipment limitations. The initial cycle pause interval is a function of the degree transition time (i.e., time required for system to change temperature one degree as measured during continuous on-time mode); the initial cycle on-time interval becomes the established minimum interval. Cycle intervals are modified as necessary to maintain the temperature at the set point with preference given to minimizing the cycle on-time interval. Hence, the cycle on-time interval is decreased to its established minimum before attempting to increase the cycle pause interval; conversely, the pause interval is decreased to its established minimum before increasing the cycle on-time interval. The system is predisposed to remain in the cycling mode whereby predetermined temperature variations from set point, in a direction opposed to system control, initiate a continuous on-time to bring the temperature back to set point, but only after attempting to do so with an additional modified cycle. Degree transition time and initial pause and on-time intervals are re-established during each continuous on-time mode. Cost savings provided by cycling, as compared to continuous on-time, are periodically computed. |