Temperature validation of an advanced hygrothermal model: Statistical analysis

Abstract

Portuguese school buildings are generally characterized by an in-service thermal discomfort, due to the poor envelope thermal properties and the lack of resources for paying energy consumption. Portuguese schools are free-running buildings in a Mediterranean temperate climate, with a natural ventilation strategy. The constructive records of the past describe the existence of typified projects for school buildings replicated throughout the country, without the necessary adaptations to the particular climatic situation. Likewise, the replication of solutions in rehabilitation projects, without taking into account the climatic reality, will have repercussions on the hygrothermal environment inside the classrooms. This work studies the Portuguese Brandao basic schools (from the‘70s). About 100 non-refurbished Brandao schools will require some interventions in the near future. A prototype classroom was prepared in a Brandao school, in Porto. With this prototype, some studies were carried out regarding the thermal behavior before and after a refurbishment process, by experimental monitoring. The in situ experimental campaign consisted of temperature, relative humidity, CO concentration and energy consumption measurements. This extended experimental campaign (three academic years) was a crucial tool to validate an advanced dynamic hygrothermal model of Heat, Air and Moisture transfer-Wufi Plus. The calibration process consisted of comparing and minoring differences between experimental and numerical results of temperature. Given the duration of an experimental campaign like this and also the cost of the prototype, it was important to dominate and improve the numerical model that replies the in situ conditions and allows the studying of the other Portuguese Brandao buildings. This paper presents the temperature validation of this model in three distinct situations: (1) before refurbishment without heating, (2) after refurbishment without heating and (3) after refurbishment with heating. The main inputs were climatic dat