The U-value was determined according to the test method and
analysis software tool especially developed for outdoor test cells
[25]. This method employs a pseudo-adiabatic shell [26] that is
intended to eliminate the heat losses from every other side of the
test room except for the one being tested (in this case the roof). The
test sequence consists of a series of predetermined thermal excitations
that were specially developed to cover all of the steady state
and dynamic characteristics of building components and to ensure
that the effects of all environmental influences are clearly decorrelated.
So the PASLINK method is a thermal testing method which
is a test procedure especially developed for the particular test cells
and it is appropriate for a wide range of building components and
widely varying weather conditions. It is a parameter identification
approach, in which, a transient mathematical model of the test cell
including the test component is developed. The parameters of the
model (e.g. resistances, capacitances and heat flow admittances)