REVERSE ENGINEERING OF A 1HP HEAT PUMP

This project focuses on the reverse engineering, adaptation, and performance evaluation of a 1-horsepower (HP) air-source heat pump tailored for Nigeria's unique climatic and infrastructural challenges. Rising temperatures, erratic power supply, and high humidity levels in Nigeria have intensified the demand for energy-efficient and resilient cooling solutions. This study addresses this need by deconstructing a commercially available 1 HP unit, analysing its core components—including the compressor, condenser, evaporator, and capillary tube—and modifying them for optimal performance within the local context. The methodology involved an iterative design process, selecting and adapting components to withstand high ambient temperatures (up to 45°C), significant humidity fluctuations (20-95%), and unstable grid voltage. Key modifications included increasing the condenser surface area by 15% for better heat rejection, integrating a voltage stabilizer, and employing a capillary tube as a cost-effective, bidirectional expansion device suitable for reversible operation. The fabricated system was rigorously tested in a controlled environment, demonstrating a stable cooling capacity. Performance analysis revealed a Coefficient of Performance (COP) of 3.45 in cooling mode and 4.11 in heating mode, confirming the system's high energy efficiency and dual-functionality. The project successfully achieved its primary objectives of component analysis, demonstration of dual-mode operation, and energy efficiency evaluation. It also fulfilled secondary goals, including refrigerant cycle analysis and the design of a modular control system. The results validate the technical and economic viability of locally reverse-engineered heat pumps, which can reduce reliance on inefficient conventional air conditioners, lower electricity consumption, and decrease greenhouse gas emissions. This work provides a foundational framework for the local manufacturing and adoption of sustainable thermal comfort technology in Nigeria, contributing to energy security, climate adaptation, and technological self-reliance. Recommendations are provided for further performance enhancements, including the adoption of inverter compressors, transition to low-GWP refrigerants, and optimization of heat exchanger design.