What a difference secondary glazing makes

What a difference a secondary glazing treatment makes


Treat Of The Month


sustainability, energy efficiency, thermal secondary glazing

Working in collaboration with a local sustainability charity; ‘Sustainable St Albans’, we have been measuring the changes in the thermal integrity of windows before and after the addition of secondary glazing. The ability to translate thermal energy into visual images inspired ‘Sustainable St Albans’ to invest in a specialist camera; with the object of assisting local residents to make their building’s more energy efficient. St Albans is built on a Roman city, often with the original materials reused in later buildings. This high proportion of traditional buildings is a sustainability challenge.   Heritage buildings are generally built with materials and construction methods that can make them less energy efficient compared to their modern counterparts. Often these buildings are of wooden construction and have single glazed windows with thin glass – not very thermally efficient.  With U- values of between (5.7 – 4.7) original windows in traditional buildings offer very little thermal/acoustic protection. Comprising, on average, 20% of a building’s external surface, these poorly insulated windows have a significant impact on their overall energy efficiency. Thermal spectrum - Thermal imaging camera The visible and infrared spectrum – taking thermal images on location Infrared imagery is generated by thermography which detects heat patterns in the infrared wave length spectrum. Whilst invisible to the human eye, all objects emit energy the level of this energy is determine by its relative heat. Sensors within the camera detect these heat signatures and translated them into visible pixels. The image below gives an indication of the thermal properties of the window pre-secondary glazing from the inside of the building. Adding secondary - recorded with infrared camera Internal thermal images of after and before installation of secondary glazing Our team has recently completed an installation of a large multi-use building in London. This fine quality, yellow brick Victorian property was originally used as a warehouse. With original single glazed Victorian windows the building’s thermal and acoustic properties were deemed inadequate for its new role as an office building. Over one hundred secondary glazing units were specified and made bespoke for each window. Prior to the installation phase we decided we would us the imaging camera to document the thermal changes that took place to during this process. Before and after secondary installation Effectiveness of secondary windows compared to untreated windows viewed from the outside of the building The sophistication of this tool is only set to increase. Even with the low resolution of the resulting images we are delighted with the dramatic contrasts these pictures show between treated and untreated windows. Watch this window (space) for more examples of treatments recorded with the added bonus of thermal imagery!