Within several research projects and with the aim to optimize energy efficiency and ecological characteristics of structural building components the Department of Structural Design and Timber Engineering (ITI) at the Vienna University of Technology (VUT) developed several wood-based composite systems, which combine timber...
Structural solutions involving the mechanical interaction of timber and glass load-bearing members showed a progressive increase in the last decade. Among others, a multipurpose hybrid facade element composed of Cross-Laminated Timber (CLT) members and glass panels interacting by frictional contact mechanisms only was proposed ion the framework of the VETROLIGNUM project. While demonstrating enhanced load-bearing and deformation capacity performances under seismic loads, facade elements are known to represent a building component with multiple performance parameters to satisfy. These include energy efficiency, durability, lightening comfort and optimal thermal performance. In this paper, a special focus is dedicated to the thermal performance assessment of CLT-glass facade modules under ordinary operational conditions. Based on the thermal-chamber analysis of small-scale prototypes, reliable Finite Element numerical models are developed and applied to full-scale VETROLIGNUM solution. Sensitivity analyses are hence carried out to explore the actual thermal performance of these novel hybrid systems.
Timber building has gained more and more attention worldwide due to it being a generic renewable material and having low environmental impact. It is widely accepted that the use of timber may be able to reduce the embodied energy of a building. However, the development of timber buildings in China...
This monitoring study was initiated to collect performance data from a highly energy efficient, six-storey building located in the coastal climate of British Columbia. This work focuses on the following objectives by installing sensors during the construction:
· To provide information about the indoor environment of a highly energy efficient building
· To provide field data about the durability performance of an innovative high energy efficiency exterior wall solution for mid-rise wood-frame construction
· To provide information on the amounts of vertical movement in wood-frame exterior walls and interior walls below a roof/roof deck
This paper examines the performance and apparent temperature in cross-laminated timber (CLT) school buildings. The research presents empirical data on the performance and provides the first set of data on apparent temperature in CLT school buildings. The development is in the New England area of the Northeast of the US. The investigation was conducted in the summertime. The principal aim of the investigation is to evaluate the performance, occupants’ comfort, apparent temperature, and other thermal indices concurrently in CLT school buildings. The research intends to understand if occupants of CLT school buildings are susceptible to thermal stress in summer and assess whether apparent temperatures are consistent with sensation. The study also discusses other indices, practical implications, and applications of the outcomes. To achieve the research aim, the study considered the field measurements of variables. Occupants’ comfort is accessed using the PMV and adaptive methods of various comfort standards. During the survey, the development was occupied from 8am-6pm and partly operated from 7pm-7am. The mean temperatures during the occupied and non-occupied periods varied from 22.1°C-22.4°C. The overall RH was 59.2%. The PMV range and sensation showed the occupants were comfortable. Approximately 80% of the users were satisfied with the thermal environment. The temperatures were within the acceptable bands of ASHRAE-55, CIBSE TM52, and EN16798-1 thermal comfort models. The results showed that the apparent temperatures are consistent with the outcomes of the sensation at different periods. The mean indices ranged from 18.8°C-23.5°C. The study recommends that further research should be conducted on occupants’ comfort and heat indices in school buildings during the first few hours of occupation to understand changes that occupants can make to remove unwanted heat from the thermal environment. The study also recommends that various designers should consider heat stress analyses along with thermal comfort assessment at the design phase to determine possible interventions to improve the thermal environment of schools and other buildings.
The largest source of energy consumption and greenhouse gas emissions in Canada and around the world is buildings. As a consequence, building designers are encouraged to adopt designs that reduce operational energy, through both increasingly stringent energy codes and voluntary green building programs that go beyond code requirements...
The challenges for the use of the cross-laminated timber (CLT) system in the Brazilian agricultural market are significant. This study evaluated the thermal performance of fiber cement tiles associated with a CLT non-conventional structure compared to those of ceramic, fiber cement and aluminum roof tiles based on following thermal comfort indexes (i.e., black globe humidity index (BGHI), radiant heat load (RHL) and specific enthalpy) using physical conventional models of reduced-scale rural facilities under summer conditions. The non-conventional CLT model comprised closing walls and a lining that form a self-supporting structure with few air inlets. This model presented reduced thermal comfort indexes compared to the other conventional roofs. Moreover, the CLT model has an average black globe temperature (Tbg) of 32.9 °C, which was lower at all times compared to those of the other roofs. In conclusion, the roof with fiber cement tiles associated with the CLT structure exhibited the best performance in terms of thermal comfort, followed by the ceramic, fiber cement, and aluminum tiles. The study results allow a better understanding of the opportunities for CLT usage.
The objective of this project was to quantify and compare the environmental impacts associated with alternative designs for a typical North American mid-rise office building. Two scenarios were considered; a traditional cast-in-place, reinforced concrete frame and a laminated timber hybrid design, which utilized engineered wood products (cross-laminated timber (CLT) and glulam). The boundary of the quantitative analysis was cradle-to-construction site gate and encompassed the structural support system and the building enclosure. Floor plans, elevations, material quantities, and structural loads associated with a five-storey concrete-framed building design were obtained from issued-for-construction drawings. A functionally equivalent, laminated timber hybrid design was conceived, based on Canadian Building Code requirements. Design values for locally produced CLT panels were established from in-house material testing. Primary data collected from a pilot-scale manufacturing facility was used to develop the life cycle inventory for CLT, whereas secondary sources were referenced for other construction materials. The TRACI characterization methodology was employed to translate inventory flows into impact indicators. The results indicated that the laminated timber building design offered a lower environmental impact in 10 of 11 assessment categories. The cradle-to-gate process energy was found to be nearly identical in both design scenarios (3.5 GJ/m2), whereas the cumulative embodied energy (feedstock plus process) of construction materials was estimated to be 8.2 and 4.6 GJ/m2 for the timber and concrete designs, respectively; which indicated an increased availability of readily accessible potential energy stored within the building materials of the timber alternative.