20 November, 2018
Builders of quality, high-energy efficiency buildings know that reducing energy consumption is not enough to achieve good results; the rooms need to be comfortable, especially in terms of temperature. This principle applies to both new buildings and planned actions on existing buildings undergoing renovation and energy redevelopment. In summer, the sun’s rays hitting the walls and doors with windows cause the rooms to overheat. We all know this situation, often accompanied by high humidity, which causes fatigue, loss of concentration, glare and excessive sweating.
HEAT REDUCTION STRATEGIES
Here are the main actions that can be undertaken to reduce solar penetration and heat dissipation in our rooms.
Building physics principles confirm that mass walls contain greater amounts of heat compared to structures that use lighter materials, although insulating. This heat storage property is defined as heat capacity. Anyone will feel fresh inside a building made of thick stone blocks, such as a Romanesque church or a medieval castle, even on the hottest days.
Equipped with sensors that monitor the main internal environmental parameters, controlled mechanical ventilation systems automatically ensure air renewal and promote excess heat dissipation, without having to open any windows.
Natural cooling, achieved by allowing the warm air inside the rooms to circulate and exchange as fast as possible with cooler air after sunset, is certainly a healthy habit at no cost.
In addition, you can use some shading systems, which protect the home from the sun’s rays before they penetrate through your glass doors and windows and overheat the rooms. The word “shading” refers to: drop-down awnings or overhangs (such as the traditional types with folding arms), sun blinds with adjustable slats and Venetian blinds.
To improve the effect, these devices must be positioned outside the windows and, to receive the ecobonus (the tax deduction of expenses incurred), they need to be movable. Moving them makes it possible to adjust the level of solar protection and shading from sunlight during the day, and to completely remove them in winter. Whereas solar films applied to windows cannot adapt to variable visibility, solar radiation and temperature.
A study on the behaviour of buildings in summer, commissioned by ANIT (the Italian National Association for Thermal and Acoustic Insulation) and conducted with several companies in the industry, compared dozens of new buildings, built according to different construction standards, in places with different climatic conditions, to evaluate the actual effectiveness of each of the above summer strategies. Using sophisticated performance simulation software, it was found that investing resources in the thermal storage capacity of brick walls and installing mechanical ventilation systems are not necessary and sufficient to perceive increased comfort in summer, which on the other hand can be achieved through shading systems combined with natural cooling systems.
Sunlight protection with shading systems is the most effective solution. Immediately reducing the causes of unbearable heat inside a living or a working space is no doubt more effective than installing any other systems afterwards in an attempt to dissipate the thermal energy produced or accumulated inside.
The study also showed that the lack of proper solar shading systems causes the rooms to overheat, regardless of the type of masonry used. We should not forget that in addition to increased comfort, solar shading systems help save energy by reducing the costs incurred for cooling the house – often with low-efficiency air conditioners.
The Pronema catalogue includes several types of shading systems to choose from to find the most suitable solution for any building.
Architetto, consulente energetico CasaClima. Professore Politecnico Milano e ITS Varese. Consulente tecnico presso Pronema Srl. Web communication (edilizia zero consumo, agevolazioni fiscali).
Architect, energy consultant CasaClima. Professor at Politecnico Milano and ITS Varese (Italy. Technical consultant at Ponema Srl. Web communication (zero construction consumption, tax breaks).All articles by this author LinkedIn Website
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