Annals of the Assembly for International Heat Transfer Conference 13

ISBN 1-56700-225-0 / CD 1-56700-226-9

Year 2006

J. Deans
Department of Mechanical Engineering, University of Auckland, Auckland, New Zealand

A. Weerakoon
The University of Auckland, Auckland, New Zealand

P. Richards
The University of Auckland, Auckland, New Zealand

I. McClew
Dimond, Auckland, New Zealand

The use of commercial roofing panels to collect the incident solar radiation arriving at a building wall and transforming this energy to provide background heating within the building has been investigated. The results show that the ambient air which flows through an array of holes pierced in the panel can extract almost 60% of the incident solar radiation. The air passing through the panel flows into the air gap behind the panel. In this heating system the panel and the gap behind it effectively act as a single stream heat exchanger with variable mass flow. The air warmed by the panel is transferred to the building's heating system.
This paper reviews both the analytical and experimental studies that were directed towards optimisation of the heat exchanger's design. The experiments were performed using two different types of roofing panel each with its own distinct profile. The panel porosities, suction flow rates and air gap geometry, were varied on a dedicated test rig that was exposed to local weather. Analytical study was conducted using a simple Excel model to determine energy balances and a CFX finite volume model to investigate flows in the air gap. This analysis has enabled new insights to be gained about the mode of heat transfer from the panel to the air and the importance of the air gap behind the plate.

ENR-01 pages DOI: 10.1615/IHTC13.p24.10 Download article

Article price - $35.00

  Next article >>