Beating the heat on high rise sites

Japan has had mandatory heatstroke prevention measures in place since June 2025, however, managing the ambient conditions on a working construction site is a challenge. The regulations apply for any work is to be carried out for more than one hour (continuously) or more than four hours in total over a day, in an environment where the temperature is 31^oC or higher or the heat index 28 or higher.

Carrier Japan developed a temporary cooling system that has been deployed at the Tokiwa-bashi site, where Tokyo Torch is currently under construction.

This aims to improve worker comfort and support heat stress prevention in what Carrier describes as “one of the industry’s most challenging construction environments.”

Unlike conventional spot coolers, which supply cooled air but release the hot exhaust air back into the same space, the new system discharges heat outside the building through openings in the curtain wall structure.

The system incorporates Carrier Japan’s Single Ace u™ packaged air-cooled air conditioning units, with the unit mounted on a dedicated moveable platform, which allows it to be relocated as works progress.

The technology also incorporates integrated supply and exhaust ductwork together with a specialized heat-rejection mechanism. The result is what Carrier describes as a temporary cooling system “specifically engineered for the demanding thermal conditions found on high-rise construction sites.”

Prior to deployment at the Torch site, the company established a test environment at its Fuji Operations location, replicating the actual conditions of a construction site. Evaluations of equipment performance were undertaken with representatives from Shimizu in attendance, and airflow and cooling performance were verified.

“This joint development project with Shimizu demonstrates how we can combine our engineering-to-order capabilities with our deep HVAC expertise to rapidly customize, validate and deploy solutions for highly specialized applications,” says Mineo Maruyama, President of Carrier Japan.

“The insights gained through this project will help us further enhance this temporary cooling solution and expand the application of heat stress mitigation technologies to construction and other industrial environments.”

---