Economic and environmental impacts of different ventilation systems in detached rural houses in severe cold climate

The growing demand for energy efficient and environmentally friendly buildings with improved comfort drives the need for advanced ventilation systems. Chinese rural houses in severe cold climate struggle with inadequate ventilation in winter, while the extremely low temperatures and huge heating demands hinder the effective implementation of mechanical ventilation. This study aims to identify the optimal ventilation system for rural detached houses in severe cold climate by examining the potential combination of earth-air heat exchanger and heat recovery, as well as comparing this system to other common ventilation solutions. Using a case building in Harbin, four mechanical ventilation configurations were simulated with IDA ICE. A multi-objective evaluation combining economic and environmental factors was employed to design the earth-air heat exchanger and evaluate different ventilation options. Results show that integrating an earth-air heat exchanger into a balanced ventilation notably reduces ventilation heating demand by 64 %, with its effectiveness particularly pronounced in colder conditions. Among all mechanical ventilation options, the balanced ventilation with both heat recovery and earth-air heat exchanger achieves the lowest CO₂ emissions at 44 kg CO₂/m². Exhaust ventilation emerges as the most cost-effective option. These findings illuminate the earth-air heat exchanger's heating performance in severe cold climate. Practical recommendations balancing economic effectiveness and environmental impacts were provided to guide the design of sustainable mechanical ventilation systems for detached rural houses in extreme climatic conditions.