INTRODUCTION

 Replacing or upgrading old windows will save energy and increase comfort whether with double glazing or secondary double glazing.

Windows represent a major source of unwanted heat loss, discomfort, and condensation problems, but in recent years, windows have undergone a technological revolution. It is now possible to have lower heat loss, less air leakage, and warmer window surfaces that improve comfort and minimize condensation.

Windows can also be a major source of unwanted heat gain, but  it is possible to significantly reduce solar heat gain and improve comfort while providing clear views and daylight. This means that high performance windows can face into the sun if desired without the need for air conditioning

Energy efficient glazing not only returns heat back into the home greatly reducing heat loss, but it also maximises energy gain from a free energy source - solar energy.

The material used to manufacture the frame will affect the total window performance and govern the physical characteristics of the window, such as frame thickness, weight, and durability. It will have a major impact on the thermal characteristics of the window, because the sash and frame will represent between  10 to 30 percent of the total area of the whole  window. more

For a glossary of window terminology click here (A US site from the University of Minnesota, but lots of useful information applicable to the UK)   REALLY USEFUL!

GLASS, AND COATINGS

The thermal properties of the glass itself can be improved by changing its physical characteristics, for example in tinted glazing. However, tinted glass reduces the amount of visible light.

Low-emittance coatings have been developed to improve both heating and cooling season performance. Low-emittance coatings  (Low-E) are virtually invisible layers deposited on the glass to reduce heat flow. Coating a glass surface with a low-emittance material and facing that coating into the gap between the glass layers, blocks a significant amount of radiant heat transfer, thus lowering the total heat flow through the window. Low-E coatings are transparent to visible light.

mistergreen.co.uk offers advice energy saving home improvements,double glazing,secondary double glazing,glazing advice, glazing energy saving advice