The demonstrational Pavilion, which will be built at the Scientific Campus II of the Bulgarian Academy of Sciences in Sofia, Bulgaria, is designed to achieve the Bulgarian nearly Zero Energy Building (nZEB) standard. It consists of:
- Glass envelope - Water Flow Glazing (WFG) modules on three facades
- Roof-mounted 4.8 kWp photovoltaic system
To simulate processes in the Pavilion, the IDA ICE software was used, which has the functionality to model sophisticated simulation applications to study the indoor climate as well as the energy consumption of the entire building. In order to enable the simulation of dynamical physical changes within the WFG facade, the software was enhanced by integrating a specific tool developed as part of InDeWaG project. The simulations were made with different combinations of glass type and position of the argon and water chambers corresponding to the three types of WFG modular units so called iThermGlass, HeatGlass and CoolGlass. The highest annual monthly average Water Heat Gain and lowest annual monthly average Internal Heat Flux are obtained for HeatGlass, which makes this module type the best choice for the local climate conditions. To estimate the effect of using WFG modules another simulation was prepared in which WFG modules are replaced by standard triple glazing windows.
The figures present the monthly electrical consumption of the Pavilion with WFG modules and triple glassing window: white - equipment, red - heating, the blue - ventilation, blue with shadows - cooling, yellow-lighting is presented.
The simulation shows a significant difference in energy consumption between the WFG case and the standard triple glazing. The total peak consumption of the WFG module doesn't exceed 700 kWh on monthly bases compared to a maximum of 2000 kWh/monthly for the triple glazing.
The most substantial energy effect comes for cooling where the difference in electrical energy consumption is almost 15 times less in the case of WFG. The difference in energy consumption for heating is 3 times lower for the WFG case due to the reason that the heat flux from inside to outside is minimized.
Electricity production from the PV system is calculated by using PVGIS solar radiation database and is estimated to be 7384 kWh/year.
On yearly bases the PV electricity production will exceed the consumption of the pilot building by 3256 kWh, which makes it energy plus building, covering the nZEB standard in Bulgaria.