Instead of using a single, huge air conditioning unit to cool an entire building, both comfort and energy efficiency can be achieved by separating “ambient cooling,” the base cooling to condition the outside air and heat generated from lighting, from the “task cooling,” the zone cooling to condition the constantly changing heat generated internally and from human activity. Both of these processes utilize a network of sensors to maintain comfort.

Kajima has also developed a “universal comfort” vent to provide a soft flow of air. Up to now in Japan, it has been considered best if people did not feel any draft, but with this system people are able to select whether or not they feel the flow of air depending on their preference. Particularly in the summer, even if the interior temperature is relatively high, a gentle breeze provides a sense of coolness.

Means of conserving energy include more than just simply reducing the amount of consumption. Another important aspect is using electricity during the night to reduce the amount employed during peak daytime hours. Kajima was one of the first companies in the industry to begin development of such thermal storage air conditioning technology.

With this system, chilled water or ice is generated using electricity during the night, and the coolness released during the day to cool the air and aid the air conditioning system. Kajima has also developed a structural thermal storage system in which cold air is blown over the concrete floors of a building at night to use them to store thermal energy that can be used to help cool the building during the day. By combining the versatile ice thermal heat pump system and structural thermal storage cooling technology, Kajima has been able to achieve both versatility and practicality. It will not be long before the word “hybrid” is used around the world as commonly for buildings as it is for automobiles.

While new technologies to enhance energy efficiency are being developed one after another, Kajima has developed and is utilizing technology to check whether energy is being wasted in existing systems. This system uses a network running throughout the building to collect detailed information on building air conditioning and energy consumption. It continually checks, for example, under what conditions energy use peaks or whether the energy conservation systems that have been installed are operating at full capacity. Kajima is then able to make recommendations for improving operating methods, the timing for replacement of equipment or upgrades to new systems. The system not only eliminates waste in the use of equipment and electricity and lowers the burden on the environment, but also is helping to create more smart building owners who are lowering their building operating costs. Kajima will continue to actively develop technologies for energy efficiency, and make proposals to its customers for leading-edge environmental control systems (lighting plus air conditioning) that are both environmentally friendly and provide comfort. Expect to see more “energy-smart” building technologies from Kajima in the future.