PASSIVE COOLING
ROOFS Up to
64%
in the tropical climate
0
LEGEND
Up to
50-70%
of electrical energy is used to cool a building
Heat gain is through roofs
0
Water cost
Heat reduction
Capital cost
Nil
0
Solar reflectance
Psychological effects
Positive score
Not available in market
Embodied energy
Maintenance
Negative score
Not commonly used
0
0
ROOF OPTIONS
0
Insulated Reinforced concrete roof
1
Screed Reinforced concrete
Corrugated composite roof
Cool roof
2
3
Aluminum corrugate sheet
Double Skin roofs (DSR)
0
Roof structure
Secondary roof Insulation/ air gap
Insulation
Polyurethane insulation
Insulation
4
Cool coating
Primary roof 0
Roof structure
0
Roof structure
0
0
Roof structure 0
9oC
Limit to increasing insulation
0
Cyclone resistant
0 0
0
Optimizes materials properties
Works against techniques
0
0
00
0
Employed with other systems
0
0
Wrong orientation would result an increase in 5oC
70% thermal load 0
54% heat gain
Nil
Saves 34% energy
0
Secondary skin hinders heat loss at night
62% and 85% with cool roof coating.
0
0
Faciliates heat loss
0
0
0
0
0
0
0
0 0
0
0
0 0
Extensive green roofs
Intensive green roofs
5
6
Lawn / sedum
0
Lawn / sedum
Substrate
Wet evaporative roof
Innovative roofs: SHETRE
7
8
Evaporative pond
Substrate
Roof structure
Roof structure
0
0
SHETRE roof module
Water inlet
0
0
0
0
0 0
for 5 & 6
0
0
90% heat
0
Water borne viruses. 0
Extend lifespan 0
0
Insulation & evaporative cooling
0
Psychological performance 0
Requires more material
0
38.1oC (arid environment)
Needs alot of water
0
0
8oC (internal)
0
0
0
0
Works against the insulation 0
0
for 5 & 6
0
Retain 88% of runoff
Green corridor
No tall trees
Reduce urban heat island effect (UHI)
Only flat roof
0
0
Water borne viruses.
0
0
0
Works against the insulation
0
Limit to increasing substrate (200mm)
0
0
0
Lower water loss than arid environment 0
High heat capacity
Increase total comfort hours by up to 210%
0
0 0
0
No practical precedent in the market Requires start up cost to utilise
0
Evaporative cooling
0 0 0
0
0
0
0 0
0
0
0 0
Yee Ann (Ean), Tan 4576071
Report: Tan Y. A (2016). How to design passive cooling roofs to achieve comfort in a tropical climate? This factsheet was made as part of the TU DELFT AR0531 Innovation & Sustainablity. Not inteneded for commercial use. Copyrights remain with the authors of the soruce material.