Graduation Term
Spring 2025
Degree Name
Master of Science (MS)
Department
Department of Technology
Committee Chair
Sundeep Inti
Committee Member
Pranshoo Solanki
Committee Member
Jin H Jo
Abstract
The Urban Heat Island (UHI) effect has emerged as a critical challenge in modern cities. It contributes to elevated local temperatures, placing significant stress on urban ecosystems and public health. One of the primary drivers of this phenomenon is the widespread use of impervious surfaces, such as dark-colored parking lots, which absorb heat during the day and gradually release it at night. This ongoing cycle results in persistently warmer urban environments. As cities continue to expand and densify, the need for effective, sustainable strategies to reduce urban heat becomes increasingly urgent.
This project aims to explore innovative interventions, particularly in the design and management of urban surfaces, to reduce heat retention, improve thermal comfort, and enhance urban resilience. One promising strategy is the use of hydronic parking lot systems. These systems feature a network of pipes embedded beneath the parking surface, through which a fluid circulates to absorb and transfer the accumulated heat from solar radiation. By capturing and removing this thermal energy, these systems can significantly lower surface temperatures and help mitigate local heat buildup.
Despite their potential, the thermal behavior, efficiency, and optimal design parameters of hydronic systems are not well understood. This knowledge gap limits practical application and broader adoption in urban infrastructure. Addressing this gap is essential to help building owners, urban planners, and engineers make informed decisions about integrating such systems into sustainable development practices.
This study investigates the key factors that influence the performance of hydronic pavement systems. It examines how variables such as pipe material (copper, PVC, and steel), inlet fluid temperature (low, medium, high), fluid flow rate (slow, medium, high), and pipe spacing (close, medium, wide) affect system performance under varying climatic conditions. A dual-method approach was adopted, combining numerical modeling with laboratory-scale experimentation to ensure comprehensive analysis.
For the numerical analysis, over 50 distinct simulation models were developed using MATLAB. Each model simulated the thermal behavior of a parking surface over a continuous 24-hour period, accounting for both daytime heating and nighttime cooling under different weather conditions. These simulations helped quantify the effect of each parameter on pavement surface temperature. The models also considered three levels of solar radiation—200, 600, and 1000 W/m²—to reflect a range of real-world solar exposure scenarios (low, moderate, and hot day temperatures).
To validate the simulations, a custom-built laboratory test setup was developed. It included copper pipes arranged in a serpentine pattern, placed inside an insulated chamber to replicate real-world parking lot conditions. The system was monitored using temperature sensors and a pyranometer, both connected to a data logger to track surface temperature and solar radiation. During testing at 600 W/m², the lab results closely aligned with the simulation predictions, showing minimal variation. This strong correlation confirmed the accuracy and reliability of the computational model.
The simulation results highlighted that cooling effectiveness is most influenced by a combination of lower inlet fluid temperatures, closer pipe spacing (around 4 inches or 10 cm), and moderate flow rates (approximately 10 gallons per minute). Of the three pipe materials tested, copper consistently outperformed steel and PVC, particularly under high solar radiation, due to its superior thermal conductivity (~385 W/m·K). Surface temperature reductions of 8.8°C (47.84°F) under low radiation, 16.8°C (62.24°F) under moderate radiation, and 23.6°C (74.48°F) under high radiation were achieved, compared to the uncooled baseline. These outcomes were statistically validated using an ANOVA test, which confirmed the significance of the findings (p = 0.002).
In conclusion, this research offers validated insights into the design and thermal performance of hydronic pavement systems. It successfully bridges the gap between theoretical modeling and practical implementation, providing a foundation for integrating these systems into climate-resilient urban infrastructure. The results are particularly beneficial for building owners, urban designers, architects, and policy makers, who can use this evidence to support more sustainable, comfortable, and heat-resilient cities.
Access Type
Thesis-Open Access
Recommended Citation
Paramaj, Sumeet Jinnappa, "Hydronic Parking Lots: A Solution for Urban Heat Island Mitigation" (2025). Theses and Dissertations. 2070.
https://ir.library.illinoisstate.edu/etd/2070
