Adaptive HVAC Fan Timing for Variable Heating and Cooling Capacity

The patent applies dynamics by transitioning from fixed static fan delays to variable dynamic delays. The controller continuously monitors system parameters (compressor run time, temperature differentials, system type) and adjusts fan-on and fan-off delays in real-time. This dynamic adjustment allows the fan to operate optimally across varying system conditions, maximizing heat exchange efficiency while minimizing energy waste, thereby resolving the contradiction between operational simplicity and energy efficiency.

The patent implements parameter changes by modifying fan delay parameters based on detected system conditions. Different HVAC system types (furnace, heat pump, air conditioner) receive different delay parameters, and these parameters further adjust based on compressor run time and temperature differentials. This parameter adaptation enables the system to maintain high energy efficiency across diverse operating scenarios while preserving the simplicity of automatic fan control.

The patent applies dynamics by implementing variable fan speed control that adapts to system needs. Rather than maintaining constant high speed, the fan controller adjusts speed based on operational phase (start-up, steady-state, shutdown) and system conditions. This dynamic speed modulation maintains adequate air circulation for heat exchange while minimizing unnecessary energy consumption during periods when maximum circulation is not required.

The patent implements periodic action through phased fan operation patterns. The system employs different fan speed regimes during different phases of the heating/cooling cycle: higher speeds during start-up to quickly establish circulation, moderate speeds during steady-state operation, and gradually reducing speeds during shutdown to maximize heat recovery. This periodic variation optimizes the balance between circulation effectiveness and energy consumption.

The patent implements parameter changes by dynamically adjusting fan-off delay duration based on detected system parameters such as compressor run time and temperature differentials. Longer delays are applied when the system has been running extensively and significant heat capacity is available for recovery, while shorter delays are used when heat exchange capacity is already depleted. This adaptive parameter adjustment maximizes heat recovery efficiency while avoiding unnecessarily extended operational times.

The patent applies feedback by continuously monitoring system state parameters and using this information to determine appropriate fan-off delay durations. The controller receives feedback on compressor operation duration, temperature differentials across heat exchangers, and system type, then uses this feedback to calculate and apply the optimal fan-off delay. This feedback mechanism ensures that fan delays are extended only as long as needed to recover available heat capacity, preventing wasteful extension of system operational time.

The patent implements self-service by enabling the HVAC control system to automatically detect its own operational state and system type, then autonomously adjust fan control parameters without external intervention. The controller monitors system responses, identifies fault conditions through abnormal parameter patterns, and adapts fan delays accordingly. This self-diagnosis and self-adjustment capability improves energy efficiency under fault conditions while avoiding the need for additional complex control hardware or manual configuration.

The patent applies universality by designing a control system that handles multiple HVAC system types (furnaces, heat pumps, air conditioners) and multiple fault conditions through a single unified adaptive algorithm. The same controller hardware and software framework accommodate different system configurations and fault scenarios, adjusting fan control parameters universally based on detected conditions. This multi-functional approach improves energy efficiency across diverse fault conditions without proportionally increasing device complexity.