Page 109 - Polymer-based Nanocomposites for Energy and Environmental Applications

Nanoclay and polymer-based nanocomposites: Materials for energy efficiency 85

equipped with PCM wallboard, which the gypsum wallboard was impregnated with
25.2 wt% of PCM (Emerest 2326) through immersion techniques [29]. The research
showed that the thermal storage capabilities of PCM wallboard enable it to preserve
room temperature in the comfort zone for humans for longer periods of time after the
cooling or heating system was turned off. In the other hand, Neeper et al. impregnated
PCM (fatty acid and paraffin waxes) into the gypsum wallboard and examined the
thermal performance of this PCM wallboard that is exposed to the diurnal variation
of room temperature and is not directly irradiated by the sun, with the PCM on interior
partition and exterior partition, respectively [50]. It was found that the diurnal storage
2
attained in practice may be limited to the range of 300–400 kJ/m even if the wall-
board has a greater latent capacity. Moreover, the maximum diurnal energy storage
occurred when the value of the PCM melt temperature is close to the average room
temperature, and diurnal energy storage decreased if the phase-change transition
occurred over a range of temperatures. Additionally, Shilei et al. impregnated
26 wt% PCM (mixture of lauric and capric acid) into gypsum wallboard and exper-
imentally evaluated the performance of PCM wall room and the ordinary wall room
in the northeast of China in winter. The thermal performance of rooms
(5 3.3 2.8 m) was tested for 3 continuous days [51]. For these 3 days, the room
was heated by 2040 W electric heat membrane in the ceiling. The results of these
experiments showed that the PCM wallboards can weaken the indoor air fluctuation,
the scales of heating equipment, and the related investment cost. Therefore, the appli-
cation of PCM wall room will bring more benefits to the building energy
conservation field.
In order to improve the thermal inertia of light envelopes and comfort inside the
buildings, Ahmad et al. [52] realized building components incorporating PCM
coupled with a vacuum insulation panels (VIP). Two test cells were installed, and each
consisted of five opaque faces insulated with VIPs one glazed face (Fig. 3.5); one of

Fig. 3.5 View of the test cell [52].