Human thermal sensation and comfort in transient and non-uniform thermal environments

TLDR

Most existing thermal comfort models apply only to uniform, steady‑state thermal environments. This thesis presents results from 109 human subject tests conducted under non‑uniform, transient conditions in the UC Berkeley Controlled Environmental Chamber. The study measured skin, core temperatures, thermal sensation and comfort at one‑to‑three‑minute intervals while independently heating or cooling local body surfaces in a controlled chamber, and replicated the protocol in a vehicle wind tunnel to validate the models. The resulting models accurately predict local and overall thermal sensation and comfort for 19 body parts, were validated in vehicle wind tunnel tests, and are useful for designing non‑uniform and transient environments in buildings, vehicles, and outdoors.

Abstract

Most existing thermal comfort models are only applicable only in uniform, steady-state thermal environments. This thesis presents results from 109 human subject tests that were performed under non-uniform and transient conditions in the UC Berkeley Controlled Environmental Chamber. In these tests, local body surfaces of the subjects were independently heated or cooled while the rest of the body was exposed to a warm, neutral or cool environment. Skin temperatures, core temperature, thermal sensation and comfort responses were collected at one- to three-minute intervals. Based on these tests, we have developed predictive models of local and overall thermal sensation and comfort: Local thermal sensation for 19 body parts Local thermal comfort model for 19 body parts Overall sensation model Overall comfort model A separate set of tests was carried out in an automobile in a climate-controlled wind tunnel at the Delphi Harrison facility in Lockport, NY. These tests simulated conditions found in vehicles during both hot and cold weather. The subjects’ body temperatures, thermal sensation and thermal comfort were measured similarly to those in the UCB chamber tests. The results of the Delphi tests were primarily used for model validation. The validation results show that the models predicted the actual sensation and comfort votes well. The models will be useful for designing and evaluating non-uniform and transient environments in buildings, vehicles, and outdoors.