Determination of the most influential and cost-optimal building characteristics on the energy performance of commercial and industrial buildings

Abstract

Unlike other types of buildings, commercial and industrial buildings have been so far "forgotten". In addition, EPBD requirements are increasingly challenging for this type of buildings. This paper aims to identify the most building determinants of the energy performance of commercial and industrial buildings, focussing on the building envelope. Building energy simulations (BES) in TRNSYS are used to simulate the energy demand for heating and cooling in five building variants. The Pareto optimality approach that considers the economic and energetic objectives equally, is used to determine the cost-optimal solutions. The sensitivity analysis and cost-optimal study clearly reveal that airtightness seems to be the most important factor. Although heat recovery on a balanced mechanical ventilation system has a major impact on the energy demand for heating, this measure is not cost-optimal. The large impact of the U-value of the roof on the energy demand for heating is also reflected in the cost-optimal study. The insulation of the floor do not appear to be cost-optimal. Moreover, attention to construction detailing is important. The additional energy losses that can occur due to thermal bridges quickly reach significant values although solving the thermal bridges seems not to be cost-optimal.