Relationship between construction parameters and thermal loads in a building without internal gains

Abstract

The analysis of building characteristics indicates that there are some uncertainties influencing its energy performance: Environment, volumetry or operating conditions. It is important to have a low-cost system that performs this analysis and energy management by optimizing the coupling between production and consumption. Knowing the relationship between the annual thermal needs with different construction parameters can help to define this system and allow understanding the expected heating and cooling consumption based on easily available information. In this work, a numerical methodology has been applied to estimate the thermal loads of a building without internal gains. For this purpose, a simulation environment has been developed to execute a sensitivity analysis through the interconnection between TRNSYS 16.1 and GenOpt programs. Volumetry, building materials according to Spanish regulations and percentage of external windows are evaluated as analysis variables of the parametric study. Heating, and cooling loads have been calculated to quantify their influence: Older regulations imply higher annual loads; the increase in building height and area reduces the annual thermal loads and higher percentages of glazing on the external façades imply higher annual demands, particularly in the east and west orientations; the variation of the envelope results in the most influential factor. Finally, a statistical study has been performed to assess the annual trends: Heating trends point to more stability with two defined intervals, while cooling trends are more asymmetric.

Keywords

• Energy efficiency in buildings
• sensitivity analysis
• multivariable construction evaluation
• thermal loads