Field and Model Analysis of the Operational Energy Benefits of Cross-Laminated Timber Construction

The thermal mass of CLT can significantly contribute to indoor temperature moderation, leading to more efficient heating, ventilation, and air conditioning system operations and comfort, especially during peak hours. Despite these proposed benefits, existing research predominantly relies on simplified simulations with extensive assumptions. Our study involves monitoring an actual CLT building (a five-story hotel) and collecting data for two years on indoor/outdoor temperatures and thermal and moisture transport within CLT components in six rooms facing two orientations. Temperature, relative humidity, and heat fluxes are modeled with exterior weather data from the nearby weather station. This approach aims to minimize assumptions and calibrate simulation models for optimal HVAC control, which can then be replicated across various U.S. climates. This paper discusses using two advanced whole-building simulation models and comparing their performance against the measurements and each other. A traditional lightweight exterior wall assembly is simulated, and its performance is compared against the CLT assembly at the component level and for overall energy use. The findings from this study are pivotal in understanding and quantifying the operational energy benefits, indoor temperature moderation, grid service capabilities, and resilience of CLT constructions.