Paper 7
Roof Thermal Design for Naturally
Ventilated Houses in a Hot Humid Climate
Bin
Su1 and Richard Aynsley2
1School
of Architecture, Unitec Institute of Technology, Auckland, New Zealand
2Delta
T Corporation, Lexington, Kentucky, USA
Abstract
Roof thermal performance is one of the most important
factors for achieving
indoor thermal comfort in a tropical house designed for natural cross
ventilation. This study,
based on field study data, discusses roof design strategies for a
hot-humid climate by investigating the impacts of roof thermal performance
on indoor thermal comfort in a naturally ventilated house.
Conventional roof design for tropical houses mainly focuses on the
roof’s day-time thermal performance for limiting solar heat gain through
the roof structure. However it ignores night-time heat loss to the sky by
long wave radiation. This
study investigates the impacts of different roof designs on both day-time
and night-time indoor thermal comfort in a naturally ventilated tropical
house. This paper also
discusses the relationships between roof structure (and roof element)
design and roof thermal performance in the hot-humid tropical climate.
Key words: roof
thermal design, roof thermal performance, indoor thermal comfort,
naturally ventilated house, hot humid climate.
References
AIRAH: (2000). “AIRAH Handbook”. 3rd edition. Australian
Institute of Refrigeration Air Conditioning and Heating, Melbourne.
1017pp.
ASHRAE: (2005) “Handbook
of Fundamentals”. American
Society of Heating, Refrigerating and Air Conditioning Engineers, Atlanta.
pp30-22.
Auliciems A and Szokolay S: (1997).
“Thermal comfort”, PLEA Note 3, Brisbane: Passive and Low Energy Architecture
International in association with Department of Architecture, University
of Queensland. 64pp.
Aynsley R and Su B: (2002). “Estimating wind frequency for natural ventilation at
remote sites”. The International Journal of Ventilation, 1, (2), pp162-257.
Aynsley R and Su B: (2005).
“Insulation of roofs in warm climates”.
Proceedings of the Impact of Cultural Differences and Systems on
Construction Performance, 2005 CIB W92/W107 International Symposium on
Procurement Systems, Las Vegas, NV: Rotterdam: CIB published on CD.
10pp.
Dan
PD and Aynsley R: (1998). “Nocturnal
cooling of an exposed radiator surface”. Proceedings
of the 32nd Annual Conference of the Australian and New Zealand
Architectural Science Association. Wellington,
New Zealand: ANZAScA. pp185-191.
Koenigsberger OH and Lynn R: (1965).
“Roofs in the Warm Humid Tropics”. Lund Humphries, London.
Sariman A: (1998). “Architectural
design procedures for thermal performance of roofs in the warm humid
tropics”; PhD thesis. James Cook University, Townsville,
Australia.
AS 2627.1-1993: (1993). “Thermal
Insulation of Dwellings: Part 1: Thermal Insulation of Roof/Ceilings and
Walls in Dwellings”. Sydney:
Standards Australia. 116pp.
Su B:
(2001). “Estimation of natural cross-ventilation potentials of medium-density
housing in the humid tropics”. Architectural
Science Review, 44, (4), pp405-418.
Su B: (2003). “Developments
in wind tunnel studies for estimating the cross ventilation potential for
a low-rise building in a built-up area” The
International Journal of Ventilation, 2, (1), pp77-86.
Su B and Aynsley
R: (2006) “A case study on roof thermal performance of naturally
ventilated houses in hot-humid climates under summer condition”, Architectural
Science Review, 49,
(4), pp399-407.
|
