A New Option for Architecture in the Era of Extreme Heat: Patent Filed for 'Cool Skin,' a Next-Generation System for Cooling Exterior Walls. A Challenge from Fukuoka's Seiko Estate & Development.

Seiko Estate & Development Co., Ltd. (HQ: Fukuoka City, Fukuoka Prefecture; CEO: Masatoshi Takagi) has filed a patent application for 'Cool Skin,' an R&D project that integrates cooling functions directly into building exterior walls to address social challenges such as extreme heat waves, the urban heat island effect, and increasing air conditioning loads.

Cool Skin is a research and development project focused on building envelope materials and cooling systems. Aiming for the social implementation of mechanisms to suppress building surface temperature rises, the company will pursue joint research, performance testing, demonstration experiments, technical alliances, and license development with universities, research institutions, building material manufacturers, local governments, and business corporations.

## New Heat Mitigation Measures Required for the Era of Extreme Heat
In recent years, summer heat in Japan has become increasingly severe. In urban areas, the exposure of asphalt, concrete, and building exteriors to solar radiation leads to rising surface temperatures and the heating of the surrounding environment. Traditionally, the construction industry has focused on improving interior comfort through enhanced insulation, energy-efficient equipment, and better AC efficiency. However, modern architecture also requires a perspective on how building exteriors affect the surrounding urban thermal environment. If exterior walls can be made less prone to heat accumulation, it could suppress surface temperature rises, reduce AC loads, and improve the local environment.

## What is Cool Skin? | A Next-Generation Cooling System for Building Facades
Cool Skin is not merely a technology for 'wetting and cooling' walls. It is an R&D project aimed at implementing cooling functions in building envelopes while considering long-term use, maintainability, and durability. The technology utilizes 'evaporative cooling'—removing heat through water evaporation—while integrating water supply to the wall surface, water diffusion, moisture control, and sensor-based water management.

Temperature and humidity sensors detect environmental conditions, allowing the control system to adjust the volume and timing of water supply as needed. This ensures stable cooling performance over the long term while minimizing water waste. In the future, integration with IoT technology and building management systems could lead to facility-wide thermal environment management, optimized AC loads, and more efficient maintenance.

## Challenges with Conventional Sprinkling, Mist Cooling, and Water-Retentive Walls
While methods like water sprinkling, mist cooling, and water-retentive materials have been used to cool buildings and outdoor spaces, several issues remained for stable implementation in actual structures:

- Uneven water supply leading to cooling inconsistencies.
- Risks of condensation and corrosion within the wall structure.
- Difficulty in controlling water supply based on environmental conditions.

Cool Skin aims to address these issues and realize the social implementation of a system that efficiently cools entire building facades.

## Designed for Both New Construction and Retrofitting Existing Buildings
Cool Skin is intended not only for new buildings but also for retrofitting existing structures. By adopting a structure that attaches to the wall surface via brackets, the company plans to deploy it as an envelope cooling system that is easy to install on existing buildings.