Thermally Activated Walls for Reducing Energy Consumption of Cold-Climate Buildings

  • Author / Creator
    Rezvanpour, Mohammad
  • The global increase in energy usage and greenhouse gas (GHG) emissions is largely due to the ascending trend of energy consumption in buildings. To address the negative impacts of this trend, designing energy-efficient buildings is crucial. As a potential solution, thermal energy storage (TES) systems, specifically using active TES in buildings’ mass have been proposed. This thesis focuses on reducing thermal loads (i.e., space cooling and heating loads) in cold-climate buildings by investigating the implementation of two methods of active TES in walls: the use of domestic cold water (DCW) for space cooling and ventilated concrete block wall (VBW) with supply air to zone (SAZ).
    DCW can be circulated through thermally massive walls before regular household consumption (e.g., shower) (herein “DCW-wall”) to provide free cooling without wasting DCW. The study evaluated the cooling potentials of DCW-wall system through 3D transient thermal simulations and revealed that the system is effective in providing cooling energy to the zone. With low inlet DCW temperatures, the system was able to deliver a significant amount of cooling energy per day, which could contribute to a substantial portion of the annual energy demand for space cooling in cities with cold climates like Toronto.
    In VBW system air is circulated between a zone and the voided cores of a VBW, where the air exchanges heat with the wall before returning to the zone. To evaluate the system's performance, typical-day and annual energy analyses were conducted under various boundary conditions and air circulation speeds. The study found that a VBW with a 2 m/s air circulation speed throughout the day can lead to 67% more thermal energy storage when compared to having no air circulation. The annual analysis compared the energy performance between a VBW and a traditional wood-frame wall in different cold climates. In addition, an annual energy analysis showed that substituting a traditional wood-frame wall with a VBW can yield a total assisting heating and cooling of 35 kWh/m2 (wall area) for Edmonton, Canada throughout the year.
    Overall, this thesis presents two methods that can potentially reduce space thermal loads in cold-climate buildings through active TES solutions in wall system. The results of this research can provide valuable insights for building design and energy management in order to create more energy-efficient buildings.

  • Subjects / Keywords
  • Graduation date
    Fall 2023
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.