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LowerMyBills Review

by gold stone (2019-02-13)

Some materials provide LowerMyBills Review greater resistance than other, depending on the mode of heat transfer: convection, or radiation. Most insulating materials work on the principle of trapped air, gas being a good insulator. Mass insulation like fibreglass, foam, and cellulose use layers of Glass fibre, plastic and wood fibre respectively to reduce convection thereby decreasing the transfer of heat. These materials also reduce heat transfer by conduction due to the presence of trapped air. ( However, these products, like most building materials, have very high radiant transfer rates.) Heat flow by radiation has been brought to the public`s attention with high efficiency windows which commonly use the term "low E " to advertise the higher performance ratings. This value is measured in emitance or "e" values ranging from 0 to 1 (lower "E" value indicates better performance). Most building materials, including fibreglass, foam and cellulose have "E" values in excess of 0.70. Reflective insulation typically have "E" values of 0.03 ( again, the lower the better ). Therefore, reflective insulation is superior to other types of insulating materials in reducing heat flow by radiation. The term reflective insulation, in some ways a misnomer because aluminium or polyester either works by reflecting heat (reflectance of 0.97) or not by radiating heat (emitance of 0.03) whether stated as reflectivity or emitance, the performance (heat transfer) is the same. When reflective insulation is installed in wall cavity, it traps air ( like other insulation materials) and therefore reduces heat flow by convection thus addressing both modes of heat transfer. In all cases, the reflective material must be adjacent to an air space. Foil, when sandwiched between two pieces of plywood for example, will conduct heat at a high rate.In the UK current regulations require us to provide insulation that will achieve a u value of 0.16, this can be achieved by using several of our foil materials in co- junction with glass wool or polyisocyanurate (PIR) board.To give you more detail it would be advised to consult your local building control on what specification they require as we have seen many councils differ on specifications. We would recommened the following specification and have had many excellent reports on completed jobs around the UK and France. If this is a to gain more insulation and create a warm roof a DIY job, you would use 70mm of polyisocyanurate board or 100mm glass wool between your rafters, then cover the face of the rafters with a quilted foil, we would recommend Actis super 10, Super foil 19, Alumaflex or Aluthermo quatro. all these materials we stock for instant despatch. If using the foil on its own you would achieve a u- value of somewhere between 0.18 - 0.20, which is quite acceptable on a refurbishment project.