Analysis of the effect of passive strategies on a nearly zero Danish residential building by means of dynamic simulations

Increase of outdoors temperature, due to climate changes, results in warmer summers even in cold climate regions. Moreover the use of wider glazing surfaces leads to high amount of incoming solar radiation. As a consequence, the moving toward low energy buildings with the improved air tightness is raising the issue of overheating even in the middle seasons creating not negligible thermal discomfort. Through building simulation program, the effect of passive cooling strategies, such as solar shading and natural night-time ventilation, on a residential building under Copenhagen climate conditions.The main result is that a crossed use of both strategies leads to a cooling demand reduction (21 kWh/m2year) that varies between 98%-100% depending on the building’s tightness. Behavioural actions of the occupants were also considered in the calculation of the cooling energy demand and their impact on the indoor environment. When an alternative mechanical ventilation system was considered to exploit the nighttime cooling potential,results show a more constant indoor air temperature performance, just below 26˚C. Even though this temperature trend satisfied the design conditions and users’ safety,it isn’t that one required by the users (22-24°C by previous studies). This desired thermal indoor environment can be however obtained by exploiting windows opening during nigh.