Cellulose insulation is formed
from shredded paper products, mainly recycled newspapers. It is seen as being a very environmentally
friendly insulation because of the recycled content, which can be up to 100%. The insulation properties are stated to be
higher than standard insulations used, and can be varied as the insulation is
applied by spraying it into place. The
insulation is often sprayed wet to prevent dust build-up and increase
cohesion. The cellulose insulation is
treated with boronates to prevent fungal attack and act as a fire retardant.
Fibreglass insulation is
commonplace in construction. It has
good insulative properties and can be rolled into place in sheets. It is formed from fibres of molten glass
which are spun together and it is possible to include some recycled glass in
the manufacture.
Plastic foams are used
for insulation. The foams include
expanded polystyrene and polyurethane, which were up till recently expanded
using CFCs. It is for this reason that
they are the least preferred option, although their insulation properties are
good and application is easy as sheets are simply rolled into place.
Transparent insulation carries
out the functions of standard insulation materials whilst still allowing the
passage of light through it. There is
little conduction of heat due to the low density structure, of which several
variations are available. Convection and
radiation are also very much reduced.
Transparent insulation can be used to insulate solar collectors and
trombe walls, such that solar radiation can enter through the insulation but
heat losses are prevented.