Abstract:
Energy consumption is a critical factor in building design. Maintaining a comfortable
indoor temperature consumes high energy than other necessities such as lighting and
cooking. The building envelope is the main component of the building that transfers
heat between indoor and outdoor environments. During the daytime, a proper
ventilation system or an air conditioning system can control the heat in a building.
Insulation layers are also used under the roofing sheets to control the heat transfer
through the roof because a building’s roof contributes to a significant heat gain in
tropical countries.
Sustainable insulation materials have been more attractive in the last two decades due
to biodegradability, low embodied energy, availability, and non-toxicity. Sustainable
insulation materials are primarily fabricated using lignocellulose fiber (natural plant
fibers). Then it is mandatory to add binder material to adhere to fibers and the material
formulated as a composite material, and an air void should be introduced to the
combination of fiber and binder to increase insulation properties. Now the whole
material can be identified as a three-phase composite material. Thus, the volume
fraction of each phase (fiber, binder, and air void) is the most critical factor which
controls these composites’ insulation properties.
The insulation properties of the material can be analysed using experimental,
analytical, and numerical methods. Analytical and numerical methods are more
attractive than experimental methods. However, there are limited number of studies on
the effect of volume fraction with insulation properties in a three-phase composite. In
this study, the effective thermal conductivity (K
eff
) of the composite was analysed
through the analytical and numerical models and validated through the experimental
results. The results concluded that the experimental results agreed with the numerical
and analytical results. Furthermore, a novel mathematical model has been proposed to
find the K
eff
of the three-phase composite using the analytical and numerical methods.
The proposed model shows better agreement with the experimental result. Therefore,
it can be used to develop this research area further.
Citation:
Chamath, L.G. (2022). Development of coir fiber based insulative composite material to reduce thermal heat in buildings [Master's theses, University of Moratuwa]. Institutional Repository University of Moratuwa. http://dl.lib.uom.lk/handle/123/21397