PCM FOR CONCRETE BRICK WALL

1. Acknowledgement :This work has been carried out at Centre of Excellence in Thermal Energy Storage, TERI University, funded by the Ministry of Human Resource Development, Govt. of India.
 Integrating latent heat thermal energy storage using Phase Change Material (PCM) provides better thermal comfort in building and
therefore reduces energy consumption through HVAC system. This includes reduction in indoor temperature and its fluctuation in hot
climate.
 Alawadhi has reported that using three PCM filled cylinders at the centre line of the bricks resulted in a heat flux reduction of 17.55% in the
indoor space during working hours.
 Castell et al. analyzed performance of macro-encapsulated PCM in modular storage panels sandwiched between perforated bricks and
polyurethane foam for passive cooling and observed when the phase change effect is maximized the temperature fluctuations are
completely prevented.
 In this work, PCM encapsulated in cylindrical steel capsules in different combination were integrated into concrete bricks. (Encapuslation
shown in Fig 1 )
 The bricks were used to erect prototypes of south-facing walls and their performance was studied. Performance improvement is measured
from difference between inner wall temperatures & ambient temperature.
SEM-EBIC
CENTER OF EXCELLENCE IN
THERMAL ENERGY STORAGE
TERI UNIVERSITY
Fabrication and Performance Testing of Phase
Change Material Integrated Concrete Brick Wall
Rohit Ranjan, Abhinav Bhaskar, Som Mondal
Centre of Excellence in Thermal Energy Storage, TERI University
Email: rohit.ranjan@students.teriuniversity.ac.in
Fig 1 Macro encapsulation of phase
change material
 The dimension of the bricks was selected to be 9-inch length, 4-inch breadth & 6-inch height (or nearly
229 mm × 102 mm × 152 mm) and the concrete mixture ratio used was 1:2:4 (cement:sand:garvel) by
weight. (Table1)
 HS34 (PLUSS Advanced Technologies) was used as the PCM in the bricks. It has a high volumetric
latent heat capacity of 297 kJ/L.
 Relatively higher solid and liquid thermal conductivities of the PCM ensuring efficient heat transfer from
the encapsulation wall to the PCM and within the PCM. In larger quantities (200mL), it was found that
the freezing temperature was 33 ± 2 °C and melting temperature of the material was 35 ± 2 °C
 140 g of HS34 in its molten state was poured in the stainless-steel capsules and kept to solidify. Each
capsule was 7-inch long with an outer diameter of 25.4 ± 0.5 mm and a wall thickness of 2 ± 0.1 mm
Bricks
Configuration
Cement:Sand:
Gravel
Bricks
Dimension
(in)
No. of
PCM
Capsules
Weight
of PCM
(g)
Reference
Bricks
1:2:4 9 × 6 × 4 - -
2×1 PCM Bricks 1:2:4 9 × 6 × 4 2 280
3×1 PCM Bricks 1:2:4 9 × 6 × 4 3 420
Table 1 Configuration of each set of bricks integrated with macro encapsulated
phase change material
Fig 3 The variation of inner surface temperatures of
the bricks with time
Fig 2 DSC test results of HS34 used as phase
change material in the experiment.
Fig 5 Temperature difference between the outer and
inner surface of the respective walls.
Fig 4 Difference in temperature between the
reference and the PCM bricks with time
Fig 2 The wall set-up for the
experiment
 One thermocouple (k-type) each was
placed along the centre-line of the
south-facing surface of the walls and
using a thermal insulation tape. Fig 2
shows the experimental set-up of the
walls.
 The thermocouples were connected to
NI cRIO 9076 data logger through the
NI 9213 module. And temperature
readings were recorded with a 10-
minute time-gap through the NI
LabVIEW software.
 DSC test was conducted on HS34 to
evaluate the melting point and latent
heat of fusion shown in fig 2.
 The phase change in the night is
distinctly observed in Fig. 3 as the
inner wall temperature of the PCM
walls is stabilised for 2-3 hours.
 Fig. 4 shows that the 3×1 PCM wall
was more effective to reduce the heat
influx through the day; a maximum of
2.7 °C reduction in temperature in
comparison to the reference wall
 Fig. 5 shows the difference between
the inner surface temperatures of the
reference and the PCM walls.
 The negative temperature
difference indicated that the
PCM walls had higher
temperature than the
reference wall,
 The thermally responsive building element, a brick integrated with phase change material, reduces the heat flux through the wall and therefore enhances the thermal
comfort in the hot climatic condition like New Delhi.
 The 3×1 PCM bricks having three capsules filled with PCM was able to reduce the heat influx in the inner wall surface amounting to a maximum of 2.7 °C reduction in the
inner wall surface temperature in comparison to the reference brick wall.
 The performance of 2×1 PCM wall was comparatively lower than that of the 3×1 PCM wall during the day.The 2×1 PCM brick was effective during the night when we
compared the walls based on the difference in the outer and inner surface temperatures.
 While the 3×1 PCM wall had higher difference during the day, the 2×1 PCM wall had higher difference during the night with a maximum of -6.8 °C (i.e., inner surface >
outer surface by 6.8 °C). The temperature difference of 2×1PCM wall with the reference wall ranges between -2.5 °C to 2.5 °C with certain high occurrences. While the
3×1 PCM wall temperature difference with the reference wall varies between 3 °C to -3.5 °C with moderate number of occurrence.
 The current PCM integration technique can further be realized in commercial fly ash bricks and the performance may be tested.