Simplified methodology to estimate the emissivity for roof covers

Zbigniew Zapałowicz,T Kujawa,A.A Stachel,Z Zapałowicz

doi:10.1051/e3sconf/20187001021

Abstract

In a number of countries, producers of roof covers are not obliged by law to estimate the reflectivity and emissivity of their products and make them generally available. However, information concerning these parameters that characterize the surface of roof cover is relevant for building's heat calculations. Adequate choice of kind and color of the roof surface affects the amount of heat transferred between the interior and the environment. Simplified research methodology has been proposed in the paper. This methodology requires that experimental research is carried out and characteristic temperatures of roof and of the air are determined. It is then possible to estimate the emissivity for roof cover from the model of energy balance.

Highlights

Effective energy consumption is one of fundamental strategic targets of governments in many countries [1]
The amount of energy transferred between the building's interior and its environment can be significantly reduced by application of the right roofing material with right reflectivity and emissivity of roofing outer layers [13,14,15]
The present paper proposes simplified estimate methodology of emissivity for roof covers

Summary

Introduction

Effective energy consumption is one of fundamental strategic targets of governments in many countries [1]. One of ways to diminish the heat energy consumption in constructing is adequate choice of applied building materials [6,7,8]. The amount of energy transferred between the building's interior and its environment can be significantly reduced by application of the right roofing material with right reflectivity and emissivity of roofing outer layers [13,14,15]. Producers of roof covers have created organizations to promote the so called "cool roofing" [16]. They publish information concerning a.o. reflectivity and emissivity of outer layers of roof covers. The methodology requires, as a matter of fact, experimental research to be carried out, its implementation is not difficult

Model of heat transfer for roof

Experimental stand

Research results

Conclusions