Main points

Insulation materials should be free from HFCs and HCFCs:

• The choice of insulation material is governed primarily by two factors: thermal conductivity and location in the home.

• The ecological preference is for materials derived from organic or recycled sources and which do not use high levels of energy during production. However, there are certain overriding factors which will be described below.

Embodied energy, that is, energy involved in the extraction and manufacturing process, is also a factor to consider. Insulation materials derived from mineral fibres tend to be among the lowest in embodied energy and also CO2 emissions. However, overall the use of insulation saves many times the embodied energy of even the worst cases, for example 200 times for expanded polystyrene and 1000 times for glass fibre.

Table 6.1

Summary of comparative performance of insulation materials

Thermal conductivity

Expanded polystyrene slab 0.035

Extruded polystyrene 0.030

Glass fibre quilt 0.040

Glass fibre slab 0.035

Mineral fibre slab 0.035

Phenolic foam 0.020

Polyurethane board 0.025

Cellulose fibre 0.035

Table 6.1 shows the thermal conductivity of the main insulants.

Finally, there is the factor of internal strength or friability. Rockwool products are among the most stable in this respect. Extruded polystyrene foams are attractive to house builders because they have good water resistance and a stiffness that enables them to be used in cavities.

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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