This study proposes an innovative framework for designing a two-layer intelligent controller for direct expansion solar heat pump systems. The system consists of a flat-plate solar collector–evaporator with a surface area of 3.1 m², a variable-frequency hermetic rotary compressor, a hot-water storage tank with a volume of 0.1 m³, a finned-tube condenser, and a capillary tube (expansion valve). The first layer, based on hysteresis logic, utilizes DS18B20 digital temperature sensors and an Arduino microcontroller to perform basic control and energy management under normal operating conditions. This layer was designed and evaluated experimentally. The second layer comprises a PID controller whose parameters are tuned according to the system’s ARX model using the direct synthesis method. This controller activates under severe disturbances, such as sudden variations in solar irradiance or inlet temperature, restoring the system’s control accuracy to its optimal level. Quantitative results obtained from experimental implementation under three scenarios—steady-state, step disturbance, and periodic disturbance—demonstrate that the proposed controller, in comparison with the standalone hysteresis controller, reduces the RMS temperature error under steady-state conditions from 0.95°C to 0.28°C (a 70.5% reduction), and decreases the number of compressor on/off cycles from 42 to 35 (a 16.6% reduction). Furthermore, energy consumption under disturbance scenarios is reduced by 24.4% and 19.6%, respectively, compared to the standalone hysteresis controller.