Residential ventilative cooling in national energy performance regulations: properties and impact on ernergy consumption and overheating

Ventilative cooling as passive technique can limit overheating and decrease cooling energy consumption. The national energy performance regulations (EPBD) determine whether, how and under which requirements ventilative cooling can assist to reduce cooling demand and overheating. Therefore, those regulations are a key factor in the market uptake of ventilative cooling. Without a realistic and achievable approach, ventilative cooling will marginally be applied in buildings. In this study a kind of sensitivity analysis is performed to assess the impact of parameter variation on the ventilative cooling effect. One reference dwelling is selected and introduced into the EP software of Belgium, France and The Netherlands. In that way, differences in buildings characteristics between countries on the output are ignored. In the three countries ventilative cooling by means of openable windows can be taken into account, in Belgium and France as a percentage of openable windows, in The Netherlands as present or not. The ability of taking into account the properties of ventilative cooling devices is rare, although they have a significant impact on the effective operating time. As can be expected, ventilative cooling always decreases the cooling demand (28 to 74% in Belgium, 29 to 35% in The Netherlands for the studied case), especially in combination with mobile solar shading. Similar to the cooling demand, the risk on overheating in Belgium decreases by applying ventilative cooling. In France, summer indoor temperature can be strongly reduced by using openable windows, although the fraction openable windows has no effect. In The Netherlands, the risk on overheating cannot be assessed. The overall primary energy consumption of the reference dwelling is lower when ventilative cooling is applied (up to 9% in Belgium and up to 3% in The Netherlands) except for France where openable windows remarkably increase the heating demand (up to 29%). The remarkable differences between the national energy performance procedures urge the need for a European ventilative cooling standard to harmonize national energy regulations.