Thermal Simulation of a Zero Energy Glazed Pavilion in Sofia, Bulgaria. New Strategies for Energy Management by Means of Water Flow Glazing

Abstract

The building sector is primarily responsible for a major part of total energy consumption. The European Energy Performance of Buildings Directives (EPBD) emphasized the need to reduce the energy consumption in buildings, and put forward the rationale for developing Near to Zero Energy Buildings (NZEB). Passive and active strategies help architects to minimize the use of active HVAC systems, taking advantage of the available natural resources such as solar radiation, thermal variability and daylight. The building envelope plays a decisive role in passive and active design strategies. The ideal transparent facade would be one with optical properties, such as Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT), that could readily adapt in response to changing climatic conditions or occupant preferences. The aim of this article consists of describing the system to maintain a small glazed pavilion located in Sofia (Bulgaria) at the desired interior temperature over a whole year. The system comprises i) the use of Water Flow Glazing facades (WFG) and Radiant Interior Walls (RIW), ii) the use of free cooling devices along with traditional heat pump connected to photo-voltaic panels and iii) the use of a new Energy Management System that collects data and acts accordingly by controlling all components. The effect of these strategies and the use of active systems, like Water Flow Glazing, are analysed by means of simulating the prototype over one year. Summer and Winter energy management strategies are discussed in order to change the SHGC value of the Water Flow Glazing and thus, reduce the required energy to maintain comfort conditions.