E + + & ILA Studios integrate IES software from preliminary design stage to decrease energy usage of new headquarters by 52%
The Central Karakoram National Park (CKNP) is one of the most important parks in Pakistan, bordering China, Afghanistan and India.
In order to promote sustainable development of the territory, the Italian Committee Ev-K2-CNR, through the SEED project, is working in the region to support the deployment and management of the park and improve the quality of life and livelihoods of local people. Among the key focuses of the project is the design of a new sustainable headquarters building for the park.
To ensure the energy efficiency of the building, E++ and ILA Studio worked in collaboration to analyse the predicted energy usage of the building right from the early stages of the design process. Taking into account climatic and environmental considerations, they carried out the analysis using VE-Pro modules MacroFlo, ApacheSim, ApacheHVAC and ApacheCalc.
The initial simulation showed the building to be of poor performance with regards to heating, primary energy consumption and summer comfort. The winter thermal balance was mainly affected by the conduction losses through the low performance glazed façade, convective losses due to the high ventilation rate, and a very low external temperature in winter. Thus resulting in more than 88 kWh/m2y yearly primary energy heating consumption.
Given the poor performance of the glazed façade resulting in high heating consumption and low indoor comfort levels, an analysis of the impact of a series of improvements was undertaken. An improved design proposal was created taking in to consideration low budget and limited design changes, using traditional and passive solutions.
The new design proposals were: correct orientation according to the wind direction, the increase of the downwind façade opening area and the doubling of the glazed façade 20 cm towards the internal side, in order to realize a Passive Double Skin Façade. This façade would preheat the air in the heating mode and remove the unwanted heat gain during summer, just by a daily and seasonal opening control strategy. Furthermore it would increase the U-value of the façade and improve the thermal comfort by means of lower glazed surface temperature in summer and a higher one in winter.
The results showed a 52% decrease in primary energy heating consumption from 88 to 42 kWh/m2y. With regards to summer the simulation showed that, despite the opposite being expected, the optimum orientation of the building was contrary to the main wind direction. This is because the unwanted solar heat gain will be removed mainly during the non-occupied period.