Insulation reduces the flow of heat into the house in the hot seasons and out of the house in the cold seasons.

Insulation

Insulation reduces the flow of heat into the house in the hot seasons and out of the house in the cold seasons.

There are basically two types of insulation material: bulk and reflective.

Bulk Insulation

Heat Loss
Heat Loss Diagram

Bulk insulation reduces the flow of convection and conduction heat by pockets of air trapped in the fibre or particles of the material.

Typical types include:

  • Batts and blankets made from rockwool, fibreglass, acrylic fibre or wool.(A strawbale wall is a good example of a wall system with built in bulk insulation).
  • Loose fill material such as treated waste paper.
  • Rigid lightweight boards such as polystyrene and polyurethane. (Structurally insulated panels with a polystyrene core or SIPS are a good example of a well insulated building system).

Reflective Insulation

Heat Gain
Heat Gain Diagram

Reflective insulation reduces heat transfer by reflecting radiant heat on the warm side. Reflective insulation must have an air gap adjacent to it.

Typical types include

  • Reflective foil laminate made from aluminium foil laminated to a stiffer backing such as polystyrene.
  • Reflective foil laminated to one side of bulk insulation sometimes know as “Anticon”.
  • Reflective foil laminated to a plastic bubble wrap material.
  • A thicker reflective foil with perforations known as ‘Vapour permeable reflective foil sarking’

The ceiling/roof area is the major path for heat loss and gain. This area is the most important part of a building fabric to insulate. The walls and floors should also be insulated if framed or in combination with thermal mass. Reverse brick veneer with thermal mass on the inside and a well insulated framed wall to the outside is a clever use of brick veneer construction.

Heat loss diagram from http://www.yourhome.gov.au.