The creation of pleasant and comfortable public spaces suitable for mature cities has become a new task, alongside the environmental problems caused by urbanization. As a solution for these issues, creating a "Cool City" that designs air, water, light, and heat from an engineering perspective would contribute to a sustainable society. For more information see the IDTechEx report on Energy Harvesting Microwatt to Megawatt 2019-2029.
A consortium of four companies from Japan including Nikken Sekkei, Meiken Lamwood, Murata Manufacturing, and Koei has responded by launching Cool Tree Lite. Just like a tree, it is made from wood, spreads water vapor, and provides shade.
Mitsui Fudosan and Nikken Sekkei installed the first Cool Tree at Kashiwano Harappa, a community plaza within Kashiwa-no-ha Smart City in Kashiwa City, Japan. The Cool Tree creates cool spots in outdoor public spaces with the combination of environmental performance and design excellence with zero city energy consumption.
Cool Tree Features
- Three forms of "cool" to recreate forest therapy: Lattice sunshade made from hinoki cypress to block direct sunlight, a bench that uses the Peltier effect (when different metals are joined and voltage applied to produce a current, heat is absorbed and released at the junction points) to cool you as you sit and cooling mist that activates via a sensor when someone approaches.
- True hexagon shape that can be flexibly arranged based on the site
- Self-sufficient system that uses solar power and IoT control for zero city energy consumption
- Can be set up easily in as little as one day and repeatedly reused in various locations
- Utilizes thinned wood from forests in Japan and cross-laminated timber (CLT); later to be recycled as biomass power
It is becoming more difficult to spend time safely and comfortably in outdoor spaces during the summer in cities in Japan and other countries where the urban heat island phenomenon continues to be an issue. By mitigating the heat with Cool Tree's environmental technologies, the aim is to create places in the open and airy outdoors where people would want to gather and thereby contribute to the formation of local communities.
Sources: Mitsui Fusodan, Nikken Sekkei