Evaluation of Tawa Khana as a vernacular floor heating system for enhancing building energy efficiency: A case study of Kabul City, Afghanistan

This study investigates the potential of Tawa Khana, a vernacular heating system used in Asian countries, particularly Afghanistan, to improve building energy efficiency. Tawa Khana utilizes radiant floor heating, drawing warmth from a cooking stove or fireplace to heat the floor and subsequently the room. However, it is neglected in contemporary designs, and there is a predicted risk of losing this valuable knowledge entirely within the next few decades. This study aims to evaluate Tawa Khana's features, including its design and construction methods, with the goal of establishing a design manual for Tawa Khana. Furthermore, it analyzes the multifaceted contributions of Tawa Khana to building energy efficiency. For this purpose, a case study evaluation with comprehensive simulations analysis through the DesignBuilder program was conducted. The results indicate that Tawa Khana is applicable with minimal additional technology, increasing room temperature by 4 degrees Celsius, demonstrating its effectiveness as a sustainable heating strategy. This vernacular technique efficiently utilizes waste heat from cooking activities, reducing reliance on conventional heating systems and promoting energy conservation.