Beyond the Thermostat: A Tripartite Investigation of Convective and Radiant Heat Transfer in Building Systems

Abstract

The purpose of this project is to assess the implementation of modern radiant thermal comfort systems. With a growing prevalence in new buildings and the potential to disrupt the dominance of traditional air-based systems, it is important to evaluate how the technology transitions from the laboratory to building architecture. The topic was tackled from three directions. First, an existing radiant system was used as a case study to evaluate its operation and effectiveness at manipulating the thermal comfort of the building occupants. Next, radiant cooling panels were tested in their standard configuration as a ceiling-mounted system to determine the extent to which they transfer heat to a space via convection, instead of the intended radiant heat transfer mechanism. Lastly, a demonstrator was constructed to illustrate how radiant systems can be reconfigured to shift the focus of thermal comfort systems away from rooms and back to their occupants. The results of the first investigation showed that the existing system was significantly underutilized due to errors in control sequence implementation. The second investigation showed that a significant portion of the heat transfer from standard panels in a ceiling-based system is actually convective, heating or cooling the air in a room. Both of these results point to the naivete of implementing radiant systems in the context of air-based systems, challenging the standard practices of radiant ceilings and floors. The final investigation and design showed that a simple reconfiguration of existing radiant thermal comfort technology can provide substantial thermal comfort differentiation within a small space. Because radiant heat transfer is agnostic to air temperature, radiant thermal comfort systems are capable of a much higher level of granularity than air-based systems. Rather than room-level heating and cooling, radiant systems can modulate thermal comfort on an individual scale when correctly applied. However, this requires a reframing of our standard practices with these systems, severing the ties to air-based system infrastructure.