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| CASE STUDY FIVE: ENVIROMENTAL AESTHEIC FACE LIFT | |
|  Project 
          type: British Gas Headquarters, 
          Staines  | Film 
          type: Duralux Long Life Solar 
          Control Film – Bronze | 
|  As 
          a part of its energy-saving policy, British Gas Trading has had a high-performance 
          solar control film applied to its glazing of its ten storey office headquarters 
          at the North Thames House, Staines, Middlesex.  A subsequent 
          energy saving analysis calculates that the film achieves an annual saving 
          of £7,274 at the current energy prices. The film Duralux 500 and made by Madico, reduces the effect of the sun's rays on the building by rejecting over 79% of the solar energy via a combination of reflecting and absorbing the sun's rays. Less heat enters the building from a solar source which keeps the interior at a more even temperature all year round, ensuring the air-conditioning functions at a more economical rate and makes the cost savings possible. |   | 
| The 
          use of an exterior grade film made it unnecessary for the installers 
          to enter the office premises to fix the film: hence no interruption 
          to the office routine was caused during the worked. Because the film 
          is applied to the external face of the glazing, it reflects heat away 
          from the glass surface back into the atmosphere. | The solar control film was installed on the external face of the glazing working mainly from cradles suspended from the building. As a result, the glass is not subjected to the high levels of heat gain that could occur if the film was applied internally. This avoids the possibility of the glass in the double glass units cracking as the result of thermal stress. |