Thermal insulation

Thermal insulation reduces this unwanted transfer. For walls, the two assessed properties are their thickness and the thermal conductivity of the material.

Two important ways to reduce unwanted transfers are lubrication and thermal insulation.

Thermal insulation slows an unwanted transfer by making it harder for energy to pass through a material or for warm air to move away. Materials that trap pockets of still air are useful because air is a poor thermal conductor when it cannot circulate freely. Loft insulation, for example, reduces energy transfer through a roof.

Thermal insulation reduces the rate of this transfer. Insulating materials are poor thermal conductors, so energy passes through them more slowly by conduction. Materials containing many pockets of trapped air can be effective because air has low thermal conductivity.