Document Type

Article

Source of Publication

Applied Mathematical Modelling

Publication Date

10-1-2022

Abstract

A simple mathematical model to estimate the energy stored in a green roof is developed. Analytical solutions are derived corresponding to extensive (shallow) and intensive (deep) substrates. Results are presented for the surface temperature and energy stored in both green roofs and concrete during a typical day. Within the restrictions of the model assumptions the analytical solution demonstrates that both energy and surface temperature vary linearly with fractional leaf coverage, albedo and irradiance, while the effect of evaporation rate and convective heat transfer is non-linear. It is shown that a typical green roof is significantly cooler and stores less energy than a concrete one even when the concrete has a high albedo coating. Evaporation of even a few millimetres per day from the soil layer can reduce the stored energy by a factor of more than three when compared to an equivalent thickness concrete roof.

ISSN

0307-904X

Publisher

Elsevier BV

Disciplines

Engineering | Mathematics

Keywords

Green roof, Heat island, Climate change, Mathematical model

Indexed in Scopus

no

Open Access

yes

Open Access Type

Hybrid: This publication is openly available in a subscription-based journal/series

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