The system connects large-scale portable air conditioning units to completed ventilation ducts within buildings under construction. The project was piloted for the first time at a new mid- to high-rise office building site currently under construction in Chuo Ward, Tokyo.

This marks the first case in Japan’s construction industry where a building is fully cooled prior to the commissioning of its permanent HVAC systems, with the goal of improving working conditions for laborers during the summer months.

By using completed air ducts and integrating them with powerful temporary air conditioning equipment, Obayashi enables whole-building climate control even before the facility's official mechanical systems are operational. The company sees this innovative approach as a proactive measure to safeguard workers’ health and comfort amid rising temperatures and increasing heat-related risks on construction sites.