Performance Data for Reflective Blinds

The problem we face, given our scientific understanding on window insulation, is that the performance of a window with a Reflective Blind will vary depending on the glass type and frame specifications. These charts will enable you to compare each of the Reflective Blind films in the same window, on the one chart, and then by comparing it with the other chart you can see what happens to performance when the frame material changes.

One is for the industry ‘Standard Window’ : This window is defined as a basic aluminium frame 1.5m X 1.8m, with 3mm plain window glass.

The other is for the same size window, with the same glass, but with a timber frame.

Spectral Performance Graphs

There is one for each film currently in the Reflective Blinds range.

These graphs were obtained with the aid of a spectrophotometer, an instrument which measures the wave length of electromagnetic waves, and are the basis for the data shown in the Performance Data Charts.

Here we see the full range of spectral radiation, that is, those wave lengths given off by the sun broken into three groups: ultra violet, visible and infra red .

Two parameters are measured :

  1. Transmission which is seen as the yellow line
  2. Reflectance which is seen as the blue and green lines

Here you can see that some films are more reflective when one side is facing the sun, that is, more effective at solar energy rejection than when the other side is facing the sun.

To find out how much, you really need to consult the Performance Data Charts.

Sensitivity analysis :

What is the effect of a change in window size, or the distance the blind is from the glass, on the Energy Saving Performance of a Reflective Blind ?

Here are just three sample charts to illustrate how performance varies as the window size and shape varies. It illustrates the point that you cannot quote a universal number for the energy saving performance of a blind which applies to every window.

What is the effect of a change in the distance from the glass a Reflective Blind is hung on the Energy Saving Performance of the Reflective Blind ?