Assessment of building retrofit options using hygrothermal analysis tool

As the stock of buildings in our society ages, it is expected that there will be an increase in building envelope rehabilitation work. Such activities represent an ideal opportunity to modify the existing wall system to improve building envelope durability and energy efficiency. This could be done by addition of insulation and sealing air leakage paths. However, there is very little information available on how to assess the moisture and energy (i.e. thermal) performance of retrofitted building envelope assemblies and select the optimum retrofit options that will maximize the long-term moisture performance and the energy efficiency of the retrofitted building envelopes together. This paper presents the findings from a study that has used a two-dimensional hygrothermal simulation tool, hygIRC-2D, to assess moisture and energy performance of retrofitted masonry walls used in high-rise construction for both residential and commercial types of buildings at various Canadian locations. The results from the simulations indicate that, if heat, air and moisture transport properties of the materials and the airflow characteristics of the systems can be defined properly a hygrothermal simulation tool can be used to evaluate the moisture and thermal (i.e. energy) performance of various wall systems and associated retrofit options.\uc0 mesure que vieillissent nos parcs immobiliers, on pr\ue9voit que les travaux de r\ue9habilitation des enveloppes de b\ue2timent conna\ueetront une augmentation. De telles interventions constituent autant d?occasions id\ue9ales de modifier les murs existants de mani\ue8re \ue0 am\ue9liorer la durabilit\ue9 et l?efficacit\ue9 \ue9nerg\ue9tique des enveloppes. On peut parvenir \ue0 une telle am\ue9lioration en ajoutant de l?isolant et en rendant \ue9tanches les voies de fuite d?air. Il existe toutefois tr\ue8s peu d?information disponible sur la fa\ue7on d?\ue9valuer la performance des ensembles d?enveloppe de b\ue2timent r\ue9habilit\ue9s en termes de r\ue9sistance \ue0 l?humidit\ue9 et de performance \ue9nerg\ue9tique (c.-\ue0-d. thermique) et de choisir les solutions optimales de r\ue9habilitation qui maximaliseront celles-ci du m\ueame coup et \ue0 long terme. Ce document pr\ue9sente les conclusions d?une \ue9tude ayant utilis\ue9 un outil de simulation hygrothermique bidimensionnelle, hygIRC-2D, dans le but d?\ue9valuer la r\ue9sistance \ue0 l?humidit\ue9 et la performance \ue9nerg\ue9tique de murs de ma\ue7onnerie r\ue9habilit\ue9s d?immeubles de grande hauteur tant r\ue9sidentiels que commerciaux, en divers emplacements au Canada. Les r\ue9sultats de ces simulations ont indiqu\ue9 que si l?on peut d\ue9finir ad\ue9quatement les propri\ue9t\ue9s li\ue9es \ue0 la migration de la chaleur, de l?air et de l?humidit\ue9 \ue0 travers les mat\ue9riaux, ainsi que les caract\ue9ristiques li\ue9es au passage de l?air dans les syst\ue8mes, il est alors possible d?utiliser un outil de simulation hygrothermique dans le but d?\ue9valuer divers murs et diverses solutions de r\ue9habilitation connexes en mati\ue8re de performances hygrothermique et \ue9nerg\ue9tique.Peer reviewed: YesNRC publication: Ye