Modern Homes
The surface emissivity
describes the potential of a
material to give off energy in
the form of thermal radiation
etc. With a non-reflective,
high emissivity finish, black
surfaces are well suited
to controlling the surface
temperature. In this way,
relatively low insulation
thicknesses can be used
for the reliable control of
condensation.
Keep water vapour out of
insulation and off the pipe
Differences in partial water
vapour pressure force
moisture towards cold
surfaces. If water vapour
is free to pass through the
insulation surface it can cause
interstitial condensation
within the material,
dramatically reducing energy
saving performance and
increasing the risks of pipe
corrosion.
Eventually cooling air
must relinquish some of
the moisture it could hold
at higher temperatures,
creating what we know as
condensation.
Any surface cooler than the
surrounding air presents the
potential for condensation
but the risks are greater as
the temperature decreases,
making it a particular issue
for refrigeration and airconditioning pipes.
Fortunately pipe insulation
doesn’t just reduce energy
loss – it can also be used to
prevent the warm, moisture
laden, air coming into contact
with the cold surfaces
of refrigeration and airconditioning pipework.
Better in black
“The properties of an
insulation material are
important when assessing its
suitability for refrigeration and
air conditioning pipework,”
explains Ralf Springub, “it’s
essential to keep the surface
temperature above the dewpoint so that condensation
cannot form”. Besides the
specific thermal conductivity,
the surface emissivity of the
insulation material is critical.
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For many insulation materials
the only way to prevent this
is to apply an external water
vapour barrier – usually in
the form of a thin and easily
damaged Aluminium foil.
Closed cell FEF and PEF
materials are, however,
so inherently effective at
preventing the passage of
water vapour that they can be
considered to possess an inbuilt water vapour barrier and
do not require an external foil
to be applied.
broad street
The nature of this resistance
means that surface damage
to a closed cell FEF or PEF
insulation material is unlikely
to significantly impair or
diminish its ability to prevent
condensation moisture
ingress.
Maximising flexibility,
minimising thickness
Because FEF and PEF
insulation materials are not
reliant on an low-emissivity
external water vapour barrier
they are able to present a
high emissivity surface finish.
This can lead to notably
thinner insulation solutions
for controlling condensation
when using FEF or PEF
materials.
FEF insulation materials are
particularly practical when it
comes to insulating irregularly
shaped pipework elements
like valves and flanges.
Thanks to the flexibility of the
foam and the inherent water
vapour resistance offered
by the closed cell structure,
FEF materials can be easily
shaped and cut to size and
aren’t reliant on a externally
applied water vapour barrier
for protection against
moisture ingress.
More details on the
advantages of technical
insulation materials made of
FEF and PEF and their use is
available to expert planners
and users on the website of
the association:
www.cefep.co.uk.