Boundary-Resolved Thermal Sufficiency of Occupied Zones in a Hot-Desert Freeway Deck Park

Abstract

Hot-desert deck parks need thermal evidence of whether occupied spaces reach comfort-relevant end states, not whether the design reduces some calculated heat load. In this paper, a novel Residual Thermal Sufficiency Analysis (RTSA) is formulated based on COMFA, an approach used to quantify distances between final temperatures and comfort intervals for adults and children. The application of RTSA is demonstrated for a 31,700 m² freeway deck park in downtown El Paso, Texas, considering the documented local climate, ENVI-met simulation validation, COMFA sensation limits, changes in site-scale microclimatology, and four occupied-place level COMFA transitions. RTSA helps answer questions about which spaces reach thermal sufficiency after the design, which do not and remain either warm or cool, and what physical control measures need to be applied to close the rest of the distance. The response to intervention at the site scale was relatively modest, involving a 0.67 ^∘C drop in air temperature and a 0.30% increase in relative humidity, while substantial reductions were achieved for solar radiation (−25.2%) and wind speed (−17.2%). At the place scale, however, a different ranking emerged. Water plaza had the greatest reduction in COMFA value (from 247 to 69 W m⁻²), yet it retained significant adult and child heat residual (19 and 29 W m⁻² according to Brown and Gillespie thresholds). Amphitheater and pedestrian street had similar performance, falling from 147 and 149 to 46 and 42 W m⁻², achieving adult sufficiency under the Brown and Gillespie limits, respectively. Pedestrian street had just 2 W m⁻² exceeding the child upper limit. Winter green patch was adjusted from −101 to −55 W m⁻². The findings highlight the necessity of focusing thermal design decisions on residual distance, occupant category, season, and activity zones. RTSA can show designers in which spaces further canopy, misting, surface cooling, or permeable shelter from wind needs to be considered.