Civil Engineering Reference
In-Depth Information
from those with porous media. The fibrous insulation materials, their composites,
properties of the composites, their applications and available studies on most
relevant to vegetable-based fibres are reviewed with an overview of the oppor-
tunities and challenges associated with their utilization. Finally, some open
problems that may in turn play important role in years to come are discussed and
several research perspectives are proposed. The chapter provides a guide to the
fundamentals and latest developments in building insulation technology for veg-
etable fibrous materials.
2 Overview of Nearly Zero Energy Building and Insulation
2.1 Nearly Zero Energy Building
Directive 2010/31/EU (
2010
) defines ''Nearly Zero Energy Building'' (NZEB) as a
building that has a very high energy performance. The nearly zero or very low
amount of energy required should be covered to a very significant extent by energy
from renewable sources, including energy from renewable sources produced on-
site or nearby. Since the Directive did not provide a definite energy requirement of
NZEB technically, researches on applications of the definition from different
Member States are still on-going. But NZEB commonly refers to the operational
energy of the building, ignoring the energy inputs from the construction and
delivery of the building and its components. Good thermal insulation, high levels
of air tightness and ventilation with very efficient heat recovery are essential for
minimizing energy usage. The use of thick and very airtight insulation, or even
super insulation, is no doubt one of the essential solutions. Figures
1
and
2
show
the changes of insulation thickness in both walls and roofs between 1982 and 1999
in Europe (Papadopoulos
2005
). Increasing trends are clearly seen over the years.
2.2 Building Insulation
In buildings, thermal insulation is installed in various types of building con-
struction such as walls, roof, floor, pipes and ducts to protect the building and to
provide thermal comfort for its occupants. Table
1
presents some of the examples
(Desideri et al.
2012
).
The materials of the insulation are used to reduce heat transfer and satisfy the
requirements depending on the building construction design, climate, energy costs
and many other factors. Combination of different insulation materials is often
applied to achieve an optimum of the overall thermal performance. The design and
control of building systems is a complex process which necessitates the use of
