Brother is making an effort to reduce its CO₂ emissions as part of its goals for the Brother Group Environmental Vision 2050 announced in 2018, and this includes contributions through its products. The majority of CO₂ emissions worldwide originate from fossil fuel combustion used for power generation. Therefore, developing highly efficient, energy-saving, environmentally friendly products and reducing energy use (power consumption) at our customers’ sites will lead to a reduction in CO₂ emissions for society as a whole. According to national statistics*, the majority of energy consumed in society is in the business sector. From this, air-conditioning takes up about 30%, second only to power for equipment and lighting, which is at 46%. Brother knows that with global warming on the rise, the need for low energy consumption cooling would grow. That is why we decided to develop an eco-friendly cooling system as a new business.

*Source: Ministry of Economy, Trade and Industry, Energy White Paper 2023

Two-stage cooling technology that focuses on the heat of vaporization of water

Conventional cooling systems are generally heat-pump types, in which a compressor compresses a refrigerant gas and releases heat to produce a cool breeze. Although the cooling performance is high, it requires a lot of electricity and generates a lot of heat exhaust at the same time as the cool breeze. In addition, the fluorocarbons used as a refrigerant have a high greenhouse gas effect and are subject to worldwide reduction policies. Brother focused on utilizing water’s natural cooling effect which draws a great amount of heat from its surroundings to evaporate. Although evaporative coolers also make use of this ability, their cooling element has limited cooling capacity. Therefore, we developed our special two-stage cooling technology that uses the same cooling element in its direct evaporation unit but is paired with indirect evaporation unit placed inside a heat exchanger.

Development of the environmentally friendly spot cooler

We used this technology in our spot coolers deployed on-site. In recent years, as the global average annual temperature has been rising, heatstroke has been occurring more frequently in warehouses, factories, and other workplaces during the summer. Unlike offices, which are designed for many employees to gather and work together, in warehouses and factories the density of workers is extremely low in relation to the vast space. This makes air-conditioning the whole area inefficient from an energy standpoint. In such an environment, spot coolers are useful to create a comfortable workspace by supplying cool air to individual workers. However, spot coolers are mainly the heat-pump type, and when Brother’s developers went around to interview users on-site, they received complaints about the heat exhaust that was generated at the same time as the cool breeze, as well as the weak airflow. Therefore, we developed spot cooler using two-stage cooling technology and succeeded in creating a cool breeze without generating heat exhaust, while consuming less than approximately one quarter of the power of a regular heat-pump type spot cooler. Furthermore, the powerful airflow also achieves a lower sensible temperature.

The completed spot coolers are already being used on manufacturing and distribution lines as well as at train and bus stations and event venues, among other places. It is leading the way to a better working environment. We also developed spot coolers for forklift trucks in response to Toyota Motor Corporation’s request for a heatstroke prevention measure for forklift operators. Our collaboration with Toyota Motor Corporation let us create prototypes and run field trials. Furthermore, we also developed a more compact model for industrial vehicles that can be used not only for forklifts but also for towing vehicles. In the Energy Conservation Best Products and Business Models category of the Energy Conservation Grand Prize sponsored by The Energy Conservation Center, Japan, its environmental performance has been recognized, with the model for forklift trucks winning the Prize of the Chairman of ECCJ in 2021 and the model for industrial vehicles winning the Prize of Director-General of Agency for Natural Resources and Energy in 2023. Brother uses environmentally friendly technologies to support industries and create safe working conditions while also cutting down on energy costs and CO₂ emissions, making our own contributions to the SDGs in various ways.