Development of the timber-glass upgrade module for the purpose of its installation on energy-inefficient buildings in the refurbishment process

Abstract

The current research study presents the development of the upgrade module consisting of a timber frame structure with the optimal glazing size in the east-, south- and west-oriented facades for the purpose of energy-efficient refurbishment of the existing energy-inefficient buildings. Such construction module could open the way to simple installation onto the existing residential, public or office buildings of various shapes and ensure better energy performance of the refurbished buildings. The optimal glazing size of the east-, south- and west-oriented facades of the module with the optimal shape is determined by the glazing-to-wall area ratio where the sum total of the annual energy need for heating and cooling of the module is minimal. The sum of the annual energy is defined through an extensive parametric numerical analysis including variations regarding the module’s aspect ratio, the thermal transmittance of its envelope and the glazing size in its east-, south- and west-oriented facades. A parametric analysis carried out in the previously described manner leads to analytic functional dependence between the energy consumption and the module’s design parameters. It is therefore possible to make a fairly simple preliminary estimate of the annual energy need, in addition to defining the optimal floor plan shape of the module along with the optimal proportion of glazing in its east-, south- and west-oriented facades. The optimal proportion of glazing varies from 24 to 91% in the south-oriented facade, from 7 to 43% in the east and from 9 to 55% in the west facade, at the thermal transmittance of the thermal envelope 0.100 W/(m2 K). The variation in the optimal glazing proportion of the module with the thermal transmittance of the thermal envelope 0.165 W/(m2 K) ranges from 14 to 85% in the east, from 28 to 97% in the south and from 16 to 68% in the west-oriented facade. The presented research study permits a choice of the optimal module design with respect to baseline characteristics of the existing building and allows for a more systematic as well as energy-efficient refurbishment process.