The Importance Air Exchange In Buildings
Environment in Buildings:
In Japan, the "Building Management
Law", a law concerning the sanitary environment in buildings,
designates 11 applications including offices, shops, and schools with
a total floor area of 3,000m2 or more, as buildings. Law maintenance
and ventilation, water supply, discharge management according to the
Environmental Sanitation Management Standards is obligatory.
Effect of Air Contamination in Buildings:
Dirtiness of interior, New
ceilings, walls and ornaments will turn yellow from dust and tobacco
smoke tar in 1 to 2 years.
The legal standards for ventilation differ according to
each country. Please follow the standards set by your country. In the
U.S., ASHRAE revised their standards in 1989 to become more strict. In
Japan, regulations are set in the "The Building Standard Law of Japan
Enforcement Ordinance", the so-called "Building Management Law" for
securing a sanitary buildings environment. According to the "Building
Standards Law", a minimum of 20 m3/h per occupant of ventilation air is
Comparing of Ventilation Methods:
There are two main types of ventilation methods.
Centralized Ventilation Method:
Mainly used in large buildings, with the ventilation air
intake being installed in one machine room. For this method, primary
treatment of the ventilation air, such as energy recovery to the intake
air and dust removal, is performed via distribution to the building by
Independent Zoned Ventilation Method:
Mainly used in small to medium sized buildings, with
areas being ventilated using ventilation air intake via independent
ventilation devices. The use of this method has recently increased as
independent control is becoming more feasible.