Could FRP Manhole Covers Help Mitigate Extreme Heat Waves?

Extreme heat waves are becoming more frequent and severe, posing a growing threat to urban populations, infrastructure, and ecosystems. One often-overlooked contributor to excessive urban heat is the use of traditional materials like metal and concrete in infrastructure components such as manhole covers. These materials have high thermal mass and conductivity, absorbing and re-radiating heat, intensifying localized warming.

FRP manhole cover , due to their low thermal conductivity, inherently absorb and store less heat than their metal or concrete counterparts. In direct sunlight, metal covers can reach scorching surface temperatures exceeding 60°C (140°F), posing risks to pedestrians, vehicles, and service personnel. FRP covers, by contrast, remain significantly cooler, reducing these hazards and improving urban thermal comfort, especially during heat waves.

Additionally, FRP can be engineered with light-colored or reflective finishes that enhance its ability to deflect solar radiation. When integrated into city streetscapes, FRP covers help mitigate micro-heat islands that form around traditional manhole covers and other dark, heat-retaining infrastructure.

Beyond surface temperature considerations, FRP covers also support the internal temperature regulation of the enclosed underground spaces. Metal and concrete covers often conduct external heat directly into utility vaults, exacerbating the temperature inside these confined spaces. Overheated vaults can cause premature degradation of sensitive infrastructure, leading to higher maintenance costs and potential service failures during peak demand periods like heat waves.

By replacing conventional covers with FRP alternatives, cities can reduce the temperature spikes inside underground systems, lowering the need for additional cooling measures and enhancing the resilience of critical infrastructure.

Moreover, FRP covers offer long-term durability without the risk of corrosion or deformation under high temperatures, maintaining their thermal performance and structural integrity during prolonged heat events.

In the broader urban heat island mitigation strategies, FRP manhole covers can be a low-cost, high-impact intervention. When deployed at scale, they contribute to overall reductions in city surface temperatures, improving livability and reducing energy demands for cooling buildings and infrastructure.

Their thermal efficiency, safety benefits, and resilience make them a critical component of climate-adaptive infrastructure.