This review analyzes the relationship between Urban Heat Island (UHI) microclimate parameters and poor air quality in urban environments, focusing on how temperature variations, wind dynamics, and urban morphology influence pollutant concentrations. Experimental studies and numerical simulations emphasize the necessity of pedestrian-level sensing combined with computational fluid dynamics (CFD) simulations to accurately capture spatial variations in UHI-related parameters. Ozone concentrations have been observed to increase by up to 4 ppbv, while PM_2.5 levels rise by 1–2 µg/m³ in response to UHI effects. Additionally, ANSYS Fluent 2020.R1. simulations demonstrate a 0.93 °C error in temperature predictions and a 1.35 m/s error in wind speed estimations. These findings highlight the critical role of sustainable urban planning strategies in mitigating UHI effects and improving air quality in densely populated areas.

During the intense heatwaves of late summer 2024, Washington, D.C.’s urban landscape revealed the powerful influence of urban morphology on microclimates and air quality. This study investigates the impact of building height-to-width (H/W) ratios on the urban heat island (UHI) effect, using a combination of field measurements and Computational Fluid Dynamics (CFD) simulations to understand the dynamics. Street-level data collected from late August to November 2024 across three sites in Washington, D.C., indicate that high H/W ratios (1.5–2.0) increased temperatures by approximately 2–3 °C and reduced wind speeds to around 0.8 m/s. These conditions led to elevated pollutant concentrations, with ozone (O₃) ranging from 1.8 to 7.3 ppb, nitrogen dioxide (NO₂) from 0.3 to 0.5 ppm, and carbon monoxide (CO) remaining relatively constant at approximately 2.1 ppm. PM_2.5 concentrations fluctuated between 2.8 and 0.4 $\mathsf{\mu }$g/m³. Meanwhile, lower H/W ratios (less than 1.5) demonstrated better air circulation and lower pollution levels. The CFD simulations are in agreement with the experimental data, yielding an RMSE of 0.75 for temperature, demonstrating its utility for forecasting UHI effects under varying urban layouts. These results demonstrate the potential of Computational Fluid Dynamics in not only modeling but also predicting UHI dynamics.

This chapter includes the basic configuration of combined cooling heat and power (CCHP) systems and provides performance analysis based on energy, economic and environmental consideration applicable to buildings. The performance parameter for energy savings measure used for the analysis is primary energy consumption (PEC) of CCHP system. Parameters used for economic analysis are the simple payback period (SPP), annual savings (AS), internal rate of return (IRR) and equivalent uniform annual savings (EUAS). The emissions savings are determined for carbon dioxide (CDE), nitrogen oxides (NOX), and methane (CH4). Economic, energy, and emission performance criteria have been utilized for three types prime movers in five different building types, consisting of a primary school, a restaurant, a small hotel, an outpatient clinic, and a small office building. Performance for economic analysis indicated that economic savings career, unlike ICE, which is preferable in terms of economic and energy savings, emission analysis shows that micro-turbine poses be observed for the ICE in all building types, and the micro-turbine in some building types. For all types of prime mover based CCHP systems, lower CO2 emission is observed for all building types. However, emission characteristics compared to other types of prime movers. Overall, CCHP system with optimum use of its appropriate prime movers can provide potential energy, economic and environmental benefit in buildings.

During the intense heatwaves of late summer 2024, Washington, DC’s urban landscape revealed the powerful influence of urban morphology on microclimates and air quality. This study investigates how building height-to-width (H/W) ratios impact the urban heat island (UHI) effect, using a combination of field measurements and CFD simulations to understand the dynamics. Street-level data collected from late August to November 2024 across three sites in Washington DC. show that high H/W ratios 2.5–3.0, significantly increased temperatures 30.12–32.10°C and reduced wind speeds 0.02–3.20 m/s, leading to elevated pollutant concentrations, with PM2.5 averaging 2.19 µg/m³. Meanwhile, lower H/W ratios less than 1.5 demonstrated better air circulation and lower pollution levels. The CFD simulations are in good agreement with the experimental data yielding an RMSE of 0.75 for temperature, thus demonstrating its utility for forecasting UHI effects under varying urban layouts. These results demonstrate the potential of CFD in not only modeling but also predicting UHI dynamics, providing valuable tools for urban planners to mitigate heat and improve air quality through strategic design decisions.