Multi foil insulation is a multi layered product comprising of many, many layers. This tends to make them thick, dense and heavy which defeats the purpose of a thin lightweight reflective insulator. It also makes them hard to handle during installation.

A lot of ‘foil’ insulation products are made from a material called mylar instead of aluminium. Only aluminium has a naturally low emissivity value. Mylar is much cheaper to produce. It is a plastic laminated or painted with aluminium coating.

Companies that use mylar claim it to be a low emissivity product. But mylar, while it looks shiny and is good at reflecting light, does not reflect heat in the same way as aluminium.

You tend to see mylar used in a lot of single use application. Emergency foil blankets, packets of crisps and chocolate wrappers. It might be good at keeping food fresh but it’s not something you want used in an insulation material.

These coated plastics crack, peel and de-laminate within a very short space of time (especially when it is exposed to heat and cold as often as insulation is), and you end up with the emissivity value of plastic rather than aluminium.

Bubble wraps and single layered products have an increased risk of the condensation forming on or in the product

Glued and laminate products contribute to fire spread, the glues break down over time and the products de-laminate, especially when subjected to heat and coldness; the way insulation is.

The obvious problem with a fibrous material is that it can absorb moisture. However, products with fibrous cores usually have multiple layers. They are typically referred to as multi-foil insulations and these can have a whole host of problems.

Low-E insulation is not designed to replace all other insulation materials on the market. It is
specifically designed to provide moisture protection, to stop draughts, to deaden sound and to provide maximum thermal efficiency.

For years, people have thought to insulate better they should simply add more and more material believing that the thicker the insulation, the more efficient it would become.

However, through the combination of the high quality Low-E insulation and the adjacent air gaps, up to 97% of radiant heat can be reflected.

The easiest way of explaining how air gaps work is to use a double glazed windows as a comparative example. Two panes of glass on their own do nothing. Yet, when they are layered and separated by an small amount of space (air gap), that is what makes them more energy efficient and the principle is the same with our ThermOsave installations.