Ventilate to adapt to new building energy performance requirements.
Because of new energy and acoustic requirements for dwellings, new constructions and renovated buildings are now basically an envelope with reinforced insulation and sealing, while older buildings are generally ‘over-ventilated’ due to leaky windows and outside walls.
In new buildings and refurbishment, when ventilation is absent or insufficient, the new air cannot enter, creating manifest problems: air quality declines and excess steam condenses on the coldest parts of the dwelling. Openings must therefore be created for fresh air to circulate through the dwelling. To overcome problems, it is necessary to recreate a ventilation circuit. Fresh new air is brought into the least polluted rooms and polluted air is extracted through wet rooms.
However, care must be taken not to ventilate in an excessive way because air renewal has one big flaw: exhausting hot air and thus contributing to energy loss. Yet building energy requirements are getting more and more strict. As a consequence, energy performance of ventilation system represents a real issue for the dwellings of tomorrow.