How does bulk insulation work

Conduction and convection types of heat are both dealt with using bulk insulation. This type of insulation is made of low density materials, normally incorporating trapped air pockets which don't conduct heat very well. Radiant heat can be reflected, and this is where reflective insulation like foil barriers come into their own. By themselves, reflective insulation only deals with radiant heat, so it's often used in combination with bulk insulation to provide maximum coverage. Reflective insulation is particularly useful in hotter climates in the north of Australia.

Heat can pass through walls, roofing, windows and doors, the floor and even through your framework. Using different materials and insulation helps to control how much heat is allowed through.

The floor and air leakage account for the remaining heat loss. In a house insulated to current requirements, the windows account for the largest single proportion of heat loss. Insulation performance is measured in R-values, which quantify the thermal resistance of a building material, or any part of a building such as the roof, wall, or floor. Commercially available insulation materials are labelled with R-values.

However, the R-value of any part of the building depends not only on the insulation but also on the thermal performance of other elements such as the framing and cladding. High density materials such as concrete, brick or stone provide excellent thermal mass but have low R-values and so are poor insulators.

Thin metals such as profiled steel claddings and fibre-cement sheets also have low R-values and are therefore also poor insulators. To determine insulation requirements, it is necessary to calculate R-values for each part of the building. See determining insulation requirements for more detail. Bulk insulation works by trapping dry air in lightweight, bulky materials. Still air is a poor conductor of heat, so bulky materials that can trap large amounts of air can reduce the ability for heat to be transferred by conduction.

Additionally, foil insulation must be kept clear of dust and dirt. It needs to remain clean to be able to reflect radiant heat effectively. This is what makes it a good choice for roof and wall insulation. However, for underfloor insulation, bulk insulation products are best. Cleverly engineered for maximum thermal performance, EXPOL fits snugly between the joists of suspended timber floors. EXPOL is a rigid insulation board. Sagging insulation creates gaps, which reduces the thermal performance and efficiency.

Sagging insulation also creates nice warm pockets for furry little creatures! EXPOL accessories now available online! Hit enter to search or ESC to close. Underfloor Insulation The difference between bulk insulation and reflective insulation. By belindak foamex. Understanding the different categories that insulation sit within, is a good place to start. There are 3 forms of thermal energy transference — conduction, convection and radiation.