
Example
of Target Technology
Sun protection film for windows

Reduction
of the indoor air-conditioning load using an envelope technology
What is the heat island phenomenon?
The heat island phenomenon means that the ambient temperature in the central
area of a city becomes higher than that of its surrounding area. There are two
main causes.
The first is an increased amount of artificial waste heat discharged from the
human use of air-conditioning systems, electrical appliances and automobiles.
The second is the increasing artificial coverage of the ground due to a decline
of vegetation and water bodies and increasing building areas and paved ground
surfaces.
Today, the heat island phenomenon has become widely known by the public as an
environmental problem specific to urban areas.
The MoE estimates that artificial heat accounts for approximately 50% of the
heat (sensible heat of the air) affecting the temperature increase of Tokyo’s
23 wards. Meanwhile, waste heat attributable to building functions, such as air-conditioning,
is estimated to account for half of the artificial waste heat.
The frequent occurrence of the heat island phenomenon and progression of global
warming have been worsening the urban heat environment, making its improvement
an urgent task. Here, it must be noted that artificial waste heat from offices
and houses if the main factor for a temperature increase in large cities.
Reference: What is the Outline of Measures Against
the Urban Heat Island EffectThe Outline of Measures Against the Urban
Heat Island Effect which was drawn up in May, 2004 puts forward basic policies
for the promotion of efforts by the central government, local governments, business
operators and residents to mitigate the heat island effect in an appropriate
manner and systematically compiles concrete measures for implementation. There
are 4 main pillars for heat island effect mitigation measures: (1) reduction
of artificial waste heat, (2) improvement of the state of ground coverage, (3)
improvement of urban form and (4) improvement of lifestyle.
The revision of the Outline in May, 2013 has added the new pillar (5) promotion
of adaptation measures to reduce the impacts, etc.on human health.