Civil Engineering Reference
In-Depth Information
High-Performance Insulation Materials
Hans-Peter Ebert
Abstract Improving the thermal efficiency of the existing building stock is one of
the key measures to deliver a substantial contribution to reduce CO
2
emissions of
our society. Novel high-performance insulation materials with superior low ther-
mal conductivity values offer several advantages in comparison with conventional
insulation products. Following a brief introduction of the principles of heat transfer
in thermal insulations, two classes of superinsulations will be discussed in detail:
vacuum insulation panels (VIP) and microporous thermal insulations. The special
features of these thermal insulations will be pointed out and best practice examples
are presented. Finally, a general summary and a discussion on future trends in
R&D for thermal insulation will complete this topic.
1 Introduction
Thermal insulation of buildings is one of the most effective ways to save energy
resources for heating and cooling and providing comfortable temperatures in living
and working rooms. Techniques for thermal insulation were historically always
applied in regions with harsh conditions by using natural materials like straw, hay,
cork or felts. The physical principle behind these efforts that were empirically
optimised with time and passed down generations is to generate a volume of still
air within a porous structure and to avoid convection effects. Thus, the thermal
conductivity of still air, i.e. 0.026 Wm
-1
K
-1
at ambient conditions, comes sig-
nificantly into effect and provides a reasonable thermal insulation. Thermal
insulation materials or systems, which show effective thermal conductivity values
far below the conductivity value of still air at ambient conditions, are known as so-
