Passive Air Cooling System and Solar Water Heater with Phase Change Material

1. Passive Air Cooling System and Solar
Water Heater with Phase Change
Material for Low Energy Buildings in
Hot Arid Climate
Prof. Dr. Amr Abdallah

3. Solar
chimney
with
PCM
Introduction
Ventilation can be achieved inside buildings due
to strong solar radiation while having large
limitations in the system after sunset and at
nighttime.
1 Solar chimneys are renewable energy systems
that provide natural ventilation in buildings.
2
The integration of phase change material with a
solar chimney is increasing worldwide.
3
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

4. Solar
chimney
with
solar
heater
Solar water heaters are one of the solar thermal
application of using renewable energy, that can
collect sunlight in the outdoor rooftop to heat
water using a pump to circulate water.
1
Recently solar water heater has been integrated
with other solar other techniques such as a solar
chimney, Phase Change Material (PCM) and
others.
2
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University
Introduction

5. No experimental studies were found for
integration passive cooling system, solar
chimney and solar water heater for low energy
building in a hot arid climate, Egypt.
Aims
Improvement of thermal performance of passive
air condition with a solar chimney integrated
with a solar water heater to be applied during
day time and night time in a hot dry climate.
Introduction
To integrate three techniques based on
improving solar chimney by using thermal
storage to increase system performance during
night time.
Importance
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

7. Experimental set-up for
solarchimney and wind
tower
The experiment in this study is done in two stages.
The first stage is investigation and
improvement of a solar chimney
with Phase Change Material and
MWCNTs as a separate system and
integrated with solar water heated.
The second stage is done to integrate
improvement of a solar chimney and
heating water system with full scale test
house and a passive cooling tower built in
Assiut University (El-Gorib site).
1
2
First Stage
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

8. The second stage is done to investigate improvement of solar
chimney model to achieve night cooling with wind tower and
passive cooling.
Second Stage
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

9. Materials and Preparation for
improvement of solar chimney
Examination of Multi-Walled Carbon
Nanotubes (MWCNTs) was done in
Housing and Building National Research
Center (HBRC), Egypt to increase
absorption of solar radiation for the solar
chimney integrated with PCM and
increase chimney performance during
nighttime.
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

10. Methodology
Measurement is carried out after painting aluminium
plate with black painting mixed with MWCNTs
without integration of PCM, and then integration of
PCM.
Monitoring for outdoor air temperature and air cavity
temperature, surface temperature of aluminium plate,
air velocity was done during beginning of hot period
(April and May) of year.
Integration of solar chimney will be done to full-scale
test house with passive cooling wind tower after
improvement of solar chimney during hot period in
June and July.
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

11.  It is observed that surface temperature of aluminium plate
increased with PCM greater than without PCM with values equal to
77.8 C and 68 C, respectively, which agrees with previous research.
Solar chimney evaluation and improvement
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

12.  Maximum solar radiation of 1089 W/m2 during middle of day (12 pm)
causes a rise in chimney air temperature and airspeed with a maximum
value of 62 C and 7 m/s respectively when outdoor temperature is 44 C.
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University
 The decrease of aluminium
surface temperature
gradually after sunset causes
also a gradual decrease in
airspeed without a sudden
drop and a significant high
airspeed greater than 1.5 m/s
during night time that is too
high than published past
research without integration
of PCM.

13.  It is observed that
temperature decreases
gradually after 12 pm
with a maximum
temperature of around
47 C during sunset.
 Then, surface
temperature decreases
gradually with a
maximum
temperature of 34.5 C
during midnight
compared to a
temperature equal to
29.5 without
integration of PCM.
After the integration of PCM.
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

14. Temperature and humidity evaluation inside the test house
• Reduction of indoor temperature is achieved with 80% of acceptable
range according to adaptive comfort standard.
. The outdoor temperature decreases gradually after it passes through
wet pad with a maximum temperature difference equal 8 k during day
time and minimum temperature difference equal 4 k during night time.
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

15. Indoor room relative humidity after cooling is within acceptable range
according to past literature. Most of indoor condition after sunset and
night time is very close to summer comfort zone.
the psychrometric chart of the condition inside the room after
cooling.
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

16. Thermal Comfort Evaluation
The calculation of PMV and PPD was
done based on Fanger’s model. The
condition is within comfort range
except during middle of the day.
While during night time, it is within
the recommended range (0.5 <
PMV<+0.5) .
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

17. 01 03 04
02
Conclusion
The water
heating system
integrated with
solar chimney
achieved water
temperature
equal to 58 C
and 40 C during
2 pm and after
sunset
respectively.
Significant
reduction for
room air
temperature
between 8 and
4 k during day
and night time
respectively
and
improvement
in building
energy
A significant
increase for the
average airflow
rate in the solar
chimney equal
1.5 kg/s
corresponding to
high solar
radiation of
1089 W/m2.
The new system
can achieve air
cooling system
with fresh air
and heating
water
Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University

18. Dr. Amr Sayed Hassan Abdallah
professor, Dept. of Architecture, Assiut University
https://www.youtube.com/
watch?v=trxzzlCpbrk
Here video for the system

19. THANK
YOU