Large glass façades are very much in vogue for office complexes around the world and yet they only make sense, in terms of energy savings and cost efficiencies, if they have integrated air-conditioning technogies to allow buildings to cool and heat 'naturally'.
Glass buildings can act like greenhouses and heat up very quickly especially in summer months and traditional air-conditioning systems require a lot of energy to cool buidlings down. According to forecasts, as many as 1.33 billion square metres of new façades will be in place by 2021 and air conditioners are currently largely responsible for buildings producing around 40 per cent of all carbon emissions in industrialised countries.
Any company planning to use glass therefore needs to install additional functions that create both shade and air conditioning. This is all the more important as fewer and fewer emissions are permitted under international climate protection targets. The member states of the European Union, for instance, have agreed that from 2020 any energy requirements of new buildings must be almost zero for heating, hot water, ventilation and air conditioning and that any additional energy requirements must be met by facilities within the building itself.
This is where multifunctional façades can be helpful. “Even in the past many elements already formed part of the façade, such as various control functions and sun protection. In the future we will see further functions being added,” says the architect Stefan Behnisch from Stuttgart. He mentions lighting elements, heat exchangers for the production of solar heat and also mechanical ventilation and aeration elements.
A foretaste of future architecture when is represented by the 67-metre Festo Automation Center with its 16 floors in the southern German town of Esslingen. The building was officially inaugurated at the end of 2015 and is based on an ingenious energy scheme. Its glass façade, which covers 8,500 square metres in all, can be described as an exhaust air façade where the air is continually siphoned off between the inner anti-glare shield, the aluminium components of the unitised façade and the glazing. This means that the heat of summer cannot penetrate to the inside of the building in the first place, thus reducing the need to cool down.