Passive cooling has several methods of cooling a structure specifically the Caribbean region. This essay will help students gain a greater understanding of ways to approach in cooling a building within the Caribbean.

1. Running Head: PASSIVE COOLING TECHNIQUES
University Of Technology, Jamaica
Caribbean School of Architecture
Building Services 1 for Architects
ARC2001
AS2
Semester 1
Lecturer: Mr. Ainsley Mills
Name: Chad Minott
1605285

2. PASSIVE COOLING TECHNIQUES 1
Abstract
Throughout the Caribbean and Jamaica in particular there has been a need for cooler air
conditioning systems that is environmentally friendly and can be applied on and within all types
of buildings. This research highlights the different Passive cooling techniques that have been
used in building systems. In Addition, the research identifies the use and application of these
passive cooling techniques. The need for eco- friendly natural cooling systems is important in
increasing human comfort within our hot tropical and equatorial climate. Hence, this research is
used as a solution to target the excess heat transfer by convection entering a building and finding
simple ways of cooling a building.

3. PASSIVE COOLING TECHNIQUES 2
Shading Devices
“Sharon! Luk how yuh hot and miserable! A time yuh get an Awning or put some opening a di
side a yuh building”.
The scenario above highlights the importance for citizens in the Caribbean region to seek
shading devices; such as Awnings, reasonable sized overhangs and louvers to control the direct
sunlight to control the amount heat within a building. Shading devices can be a part or separately
detached from a building. Similarly, shading device greatly reduces the peak heat gain and
cooling requirements; in fact it improves the natural lighting quality on the interior of a building.
In Addition, before implementing shading devices the building orientation must be consider and
region climate on a whole (Kamal, 2012). In the Caribbean, Jamaica in particular the South-
Western receives direct sun in the Afternoon and the mornings in the Winter Solstice and
Equinox. Window sizes and location on a building is also of significant importance, generally in
Jamaica on the windward side of the island,
Kingston in particular homeowners sometimes
place windows on the north eastern facade or the
south east Facade to gain access to the dominant
trade winds so it can cool down the building in the
day time. In Addition day and night breezes also
play a relevant part in orienting where windows
and openings should be placed.
Fig. 1 Sun path 18 degrees Latitude.
Fig 2. Controlled lighting using
shading techniques to cool a building.
Fig. 3. Different shading techniques used to control heat
gain with a building.

4. PASSIVE COOLING TECHNIQUES 3
Roof Shading
Roof shading is a system that helps reduce the amount of direct sun touching the building
underneath; more so it reduces heat gain within a building. Roof Shades can be adjustable,
portable, detached or attached to the existing building. Roof shading also acts a solar insulator to
block the heat flow from passing through the materials under it. Some roof shades such as plants
or simply a wood or concrete slab is placed with a gap between the wall lintel and the roof to
allow adequate cross ventilation as well allowing hot air to rise and flow through these gaps.
Fig 4. Roof shading with solid cover. Fig 5. Trellis covered roof. Fig 6. Roof shading with
plant cover
Kamal (2012) agrees that the use of deciduous plants and creepers is a good alternative for a roof
shading device. The leaf has the ability to reduce the temperature of the roof to a standard which
can be matched with that of the daytime air temperature. Kamal even states that; “at night, it is
even lower than the sky temperature”. However, some roofs use removable canvases or other
adjustable materials which is mounted over the or close to the roof. It is economical and
effective. In the daytime the canvases prevents heat from entering and its removal at night time.
The white Albedo in the white paint is also effective in reflecting the sun rays which minimizes
the radiation and conductive heat gain (Kamal, 2012).
Roof shading devices may affect the occupants visual comfort if for example a trellis is
used or an opening is in the roof which is glass covered to allow lighting cause a change in the
illuminance levels within a space (Dubois, 1997; p 89.). However, roof shading is effective in
reducing heat gain and increasing human comfort.

5. PASSIVE COOLING TECHNIQUES 4
Natural Shading
Shading using natural vegetation and trees are if not the most acceptable cooling technique.
Trees are able to absorb excessive carbon monoxide and dioxide which in turn cools and cleans
its surroundings. Excellent landscaping is required to reduce heat gain in Caribbean islands.
Kamal (2012) highlighted that shading and evaoptranspiration from shrubs and trees may reduce
surrounding temperatures as much as 5◦ C. Special trees and plants can be used at particular areas
to get the desired amount of shading.
Some benefits of using Natural shading is that it reduces air conditioning needs, creates a
cooler building microclimate and reduces heat loss from lateral wind movement. However, some
limitations are; plants must be chosen carefully so that it’s adaptable to the local micro climate. It
requires maintenance (it should not grow out of proportions). In Addition space available for
planting may be limited. Deciduous and coniferous trees should be planted on the southern
elevation along with vines and creeper on the southern facades. In fact, a tree also acts as wind
breakers which can control intense hurricane winds and noise from neighbours around is reduced
(Lighting & Daylighting, n.d.).
Identically, Shading and insulation for walls can be directly provided by plants that stick
to walls. Some are the English Ivy, or the Jasmine plant that is supported by a wall. Tall vertical
pines and deciduous trees with vines supported on frames is excellent for the west walls and
windows (Kamal, 2012).
Fig 7. Trees used to cool and
heat a building.
Fig 8. Trees used to cool and
heat a building.
Fig 9. Trees used to cool and
heat a building.

6. PASSIVE COOLING TECHNIQUES 5
Air Vents
Air vents are excellent in using on curved roofs, high pitched roofs and wind towers. This
is because hot air is forced upward where the heat is pushed out due to the formation of the roof.
It is used in combination for passive cooling of air in hot and dry climates. Usually at the apex of
a domed roof or a ridge of a high pitched roof a cap is placed there to direct the wind across it.
The opening at the top provides proper ventilation and it provides an escape route for hot air
accumulated at the top. The air ventilation system work on the basics of cooling by induced
ventilation, caused by pressure differences within the building.
Fig 10. Air Flow in a building Fig 11. Air flow and cooling system
Stack ventilation, which uses the increased buoyancy of
air as it warms up to push it out of the building. In stack
ventilation, cool air is drawn into the space low down
to replace warmer air that naturally rises as it is
warmed. This caused air flow and pushes the warm,
rising air up and out of the building (Wheeler, 2012).
Fig 13. Methods of channelling cool and exhaust
air.
Fig 14. Air Ventilation Vent is placed at the top with a
cap over it.
Fig 12. Fresh air entry and exhaust air removal

7. PASSIVE COOLING TECHNIQUES 6
Wind Tower
A wind Tower collects hot ambient air through the openings in the tower which in
turns is forced to move downwards which is cooled; whereby the heavier air sinks down. Usually
the inlet and outlet of the room below induce cool air movements. Some wind towers may have
louvers or vents to control the amount of hot or humid air entering. The top part may be divided
into several vertical air spaces ending in the openings in the sides of the rower and into the living
area. The system works excellently and is applicable in hot and dry climates where the diurnal
variations may be high (Kamal, 2012). After the whole day of air exchanges, the tower becomes
warm in the evenings. During the night, cooler ambient air comes in contact with the bottom of
the tower through the rooms (Reddy, 2015).A limitation to the wind tower design is that it is too
easily accessed by other humans or by insects and animals. Also in a place like Jamaica there
would be some security problems because criminals could have easy access in the building,
unless protective steel bars are placed on the sides of the tower. In addition rain can become a
problem.
Fig 15. Wind Tower section and its
location within a design
Fig16. WindTowerthat capturesheatin
the daytime andreleasesitinthe cool night.
Fig17. Detailedsectionof a
WindTower.

8. PASSIVE COOLING TECHNIQUES 7
Roof Pond
A shallow water pond placed over a highly conductive flat roof where the sides are fixed
with thermal insulation. The thermal insulation is movable. The pond is usually covered during
the daytime hours to prevent heating and solar heat gain. In addition, studies have shown that the
use of a roof pond can lower room temperature to about 20◦C. Furthermore, the pond is left open
during the night so that the water can be cooled by nocturnal cooling. When the pond is covered
during the day it provides cooling due to the effect of nocturnally cooled water pond, also on the
other side solar radiation is cut from the thermal insulation of the roof. The system can be used
for heating during the winter as well and used as a passive cooling agent (Kamal, 2012).
Factors that affect the performance of roof ponds are; meteorological condition
(“Increased humidity in the atmosphere reduces the potential for evaporative and radiative
cooling”) which in fact a lower relative humidity is desirable for efficient functioning of cooling
roof pond systems ( Sharifi & Yamaagata, 2015).
Fig18. Roof Pond andits applicationduringthe dayandnighttime asa passive coolingsystem.

9. PASSIVE COOLING TECHNIQUES 8
Earth Air Tunnel
The earth is used as a heat sink or a source of cooling and heating air which is usually
buried pipes or tunnels underground. Generally the air that passes through a tunnel or a buried
pipe which can be buried a few meters deep usually gets cooled in the summer time and heated
during the winters (Kamal, 2012). Architect Reddy (2015) stated that “Daily and annual
temperature fluctuations decrease with the increase in depth below the ground surface”. When
the pipes are embedded 4m below ground level it will acquire the same temperature as the
temperature at the ground level surroundings. Furthermore, the ambient air which is ventilated
through this tunnel will get cooled in summer and warmed in winter and this air can be used for
cooling in summer and heating in winter.
Cool air underground needs to rise above into the living space so it can be circulated
around. Each room should have a solar chimney that is used to push hot air out, which in fact
creates an air current for cooler air from the underground tunnels so it can replace the warm air
(Reddy, 2015).
Fig19. Earth Air tunnel with
undergroundwatercooling
system.
Fig20. Heat exchange between
the exteriorandinterior
Fig21. Earth tunnelsusedtocool a
buildingduringsummerandwarmit
duringwinter.Fig22. Earth Tunnel witha fountainandpool usedtocool the building.

10. PASSIVE COOLING TECHNIQUES 9
Earth Berming
According to Ahmed (2012) Earth Berming shelter is earth that is piled up against an exterior
wall and heaped to climb downwards away from the house (p.133 – 134). The roof may or may
not be fully covered with earth. Usually the building is placed above ground which in fact will
have less moisture settling than if it was fully covered by earth. In addition, other variation of
Earth Berming is In-hill construction which is particularly useful in cooler climates (Ahmed,
2012, P. 134).
Generally, in an earth sheltered building or earth bermed structure the reduced infiltration of
outside air and the additional thermal resistance of the surrounding earth greatly reduces the
average thermal load. More so does the earth mass acts as a large thermal mass which reduces
the fluctuations in the thermal load. It also reduces solar and convective gains (Kamal, 2012).
Underground air tunnel connection may be successful with earthbermed design also acts as a
heat sink. Earth berming is significant passive cooling technique.
Fig22. Partial Earth Shelteredbuilding
Fig23. Earth bermingdesignsthatare in- hill cut
outsand covered Earth Bermbuilding.
Fig24. Earth Berm buildingduringsummertime
conditions.

11. PASSIVE COOLING TECHNIQUES 10
Conclusion
Passive air cooling is a systematic technique used to remove excess heat gain and radiative heat
accumulated in a building. A passive cooling technique is effective in hot and dry tropical
climates. Passive cooling encompasses several techniques that are all natural and is eco- friendly
and may be economical to consumers. Hence, passive cooling plays a major role in achieving
thermal comfort for individuals and it significantly saves energy. Increase in energy use has led
many countries to seek passive cooling techniques especially during the summer season
primarily because of the need for a cooling system during the intense hot periods of the year.

12. PASSIVE COOLING TECHNIQUES 11
Reference
Anslem, A. J. (2012, October 31). Earth Shelters; A Review of Energy Conservation Properties
in Earth Sheltered Housing . Dr. Azni Zain Ahmed (Ed.), InTech, DOI:
10.5772/51873. Retrieved from: https://www.intechopen.com/books/energy-
conservation/earth-shelters-a-review-of-energy-conservation-properties-in-earth-
sheltered-housing
Dubois, M. C. (1997). Solar shading and building energy use: A literature Part 1. Lund
University.p. 89. doi=10.1.1.595.7355. Retrieved from http://citeseerx.
ist.psu.edu/viewdoc/download?doi=10.1.1.595.7355&rep=rep1&type=pdf
Kamal, M. A. (2012). An overview of Passive Cooling techniques in buildings: design and
concepts and Architectural interventions. Acta Tech. Napocensis: Civil Eng. & Arch.,
Vol. 55 (1), p 84 – 97. Published online 19.09.2012
Lighting & Dylighting. (n.d.). Shading with vegetation. Retrieved from http://www.
greenglobes.com/advancedbuildings/main_t_lighting_shading_vegetation.htm

13. PASSIVE COOLING TECHNIQUES 12
Reddy, S. (2015, January 25). Passive cooling techniques. Retrieved from
https://www.slideshare.net/swapnika15/passive-coolingtechniques
Sharifi, A., & Yamagata, Y. (2015). Roof ponds as passive heating and cooling systems:
A systematic review. Applied Energy, 160, 336–357. https://doi.org
/10.1016/J.APENERGY.2015.09.061
Wheler, M. (2012). Natural Ventilation. Retrieved from https://ssb2012marcywheeler
.wordpress.com/2012/10/13/107/