Development of a smart cooling circulation system for indoor temperature control/ Mieko Justine L. Condez, John Carlo P. Datuin, Adrianne D. Geronimo, Angelica May F. Pring, Daryll H. Tubig.--

Bachelor's thesis

College of Engineering.-- Bachelor of science in electrical engineering: Technological University of the Philippines, 2025.

Includes bibliographic references and index.

This study presents the design, development, and experimental testing of a Smart
Cooling Circulation System for indoor thermal comfort in indoor spaces like classrooms
and offices. The system integrates electric fans and air conditioning units by controlling
them using real-time temperature sensing via DHT11 sensors and microcontroller-based
control logic. The study were based according to ASHRAE standards for the accurate
measurement for the cooling load of the room. Sequential control of air conditioning units
and fan outlets is facilitated using solid-state relays for the purpose of maximizing energy
consumption, reducing inrush current, and load-balancing the operating load. Hardware
consists of a central "mother" controller and two "child" controllers for distributed sensor

input, and all hardware components are programmed using the Arduino IDE.
Experimental testing under real operating classroom conditions showed the system's

ability to maintain indoor temperatures between 24°C and 28°C consistently, and time-
based and sensor-activated activation logic showed effectiveness. The limitations of this

study include manual system activation and a restricted temperature range. The study
concludes that smart control systems offer significant potential for reducing power
consumption while improving comfort, suggesting their viability for broader applications
in energy-intensive establishments.