28 April, 2015
A building can be looked upon as a system that converts primary energy ˗ coming generally from fossil ˗ into heat, to then dissipate it in variable quantities, depending on the thermal properties of the elements of which the building envelope is composed.
The first step to reduce the energy requirements of a building is obtained by:
• Improving performance of the building envelope (exterior walls, doors and windows, attics, roofing)
• Limiting heat loss through transmission and ventilation
• Maximizing passive solar energy during the colder months
• Reducing heat during in summer to avoid overheating of the environment, by means of installing sunbreakers for example, which allow for a good balance between energy and light, or technichal blinds, all such as those proposed, in a wide range of types, by Pronema
The resulting energy balance defines the amount of heat energy necessary to ensure the maintenance of comfort in the environment, allowing for a reduction of consumption, powered by renewable energy.
The possibilities for renewable energy of an existing building are numerous and can lead to reducing fuel consumption by up to 10 times, if implemented in a professional manner.
The correct application of appropriate materials with low thermal conductivity, installing aperture fixtures of high thermal resistance, protection from solar radiation by shielding systems of glazed surfaces, the use of controlled mechanical ventilation systems with heat recovery, making the most of renewable energy sources and the adjustment of the heating/cooling system, all contribute towards making substantial savings and investments which can in some cases around the world count on strong tax advantages.
To build a low-energy building from scratch, with an annual energy requirement of less than 50 kWh/m2, you must first define an energy strategy and planning, modelled on the climatic characteristics of the site, which skilfully combines physical performance of building structures with innovative system solutions.
It is essential that the stratigraphy of each architectural element is designed in detail, both to limit the heat loss, thus reducing overall dispersion caused by the influence of thermal bridges, and to ensure the maintenance of performance over time.