RESEARCH TITLE: CONCRETE VENT BLOCKS AS EFFECTIVE

NATURAL COOLING STRATEGY IN IMPROVING THE INDOOR ENVIRONMENTAL QUALITY AT

PJ TRADE CENTRE

Concrete Vent Block as Effective Natural Cooling Strategy in Improving the Indoor Environmental Quality at PJ Trade Centre

(Concept Mapping)

Research Questions

Main Question: How effective are the concrete vent blocks as natural cooling strategy in improving the indoor environmental quality at PJ Trade Centre? Sub Questions: 1)  What are the passive cooling strategies in improving the indoor environmental

quality? 2)  What are the main roles of concrete vent blocks in natural cooling? 3)  How is the use of concrete vent block is applied to improve the indoor

environmental quality?

Design Intensions

Main: Providing a working space that is rich in textures and delight. One that serves its practical needs while prioritizing the user’s need and comfort as well. •  Bold choice of materials for modern office

headquarters: Concrete vent blocks, raw concrete, bricks •  Choosing materials that makes the building

sustainable : Lessen the maintenance, reducing construction waste and long-term energy consumption •  Basic materials which defines a duality to the site

and context, respecting the green hills behind the development.

•  Choosing materials that gives warmth and cozy interior

Concrete Vent Block

Concrete Vent blocks are ventilation blocks that is made out of concrete, which provides practical protection against heavy wind and rain while allowing sufficient amount of light and air to flow and circulate into the functional space. Other advantages of using vent blocks: -  aesthetically pleasing -  its form is flexible according to the design -  precasted at the factory > less construction waste

Type A

•  Size (mm): 310(H) x 310(L) x 125(W) •  10.4 blocks per Meter Square •  Used at the exterior facades and the interior side

Based on a research paper, the heat preservation effect of the compound concrete vent blocks is better than that of clay bricks. Furthermore, the application of lightweight aggregate concrete does not show much improvement on heat insulation properties of the small-size concrete vent blocks. [6]

Type C

•  Size (mm): 200(H) x 200(L) x 100(W) •  25 blocks per Meter Square •  Used at the exterior facades of the building

Type B

•  Size (mm): 255(H) x 260(L) x 100(W) •  15.1 blocks per Meter Square •  Used at the some part of the interior side of the building

Thermal Mass

Ø  The ability of a material to store and absorb heat energy.

Thermal mass properties of concrete: •  Delays and reduces peak loads •  Reduces total loads •  Works best in commercial building

applications •  Works when mass is exposed on the

inside surfaces •  store and absorb heat during day, re-

releases heat during nighttime Concrete material has a high thermal mass and works best in commercial building such as the PJ Trade Centre.

Orientation

•  Usually the north and the south façade is designed to be longer.

•  But in this case, architects strive to design a great and effective shading devices and consider putting more of these devices on the east façade, which is the concrete vent block.

•  The west façade is shaded by the building next to it.

•  This orientation allows air to flow and circulate better –one façade facing the highway, another façade facing rows of buildings (wind tunnels)

Natural Ventilation

•  The concrete vent block allows airflow while providing shade.

•  1 to 4 units per floor in PJ Trade Centre - the environment in each floor not too compact and thus enhance the ventilation.

•  The ventilation rate in the office is high as the occupancy is low.

-the ventilation rate is depends on the occupancy density. •  Rows of balcony as a wind scoop,

scooping the air into a building to allow better ventilation in the unit and balcony.

•  The ceiling in the office towers is 3.8 metres high – allow better ventilation

Stack effect is the way to ventilate the room to be hot or cold than the outside air temperature. Stack effect causes air infiltration, which allows air leakage into the building. The design of the sky terrace at PJ Trade Centre uses the stack effect, allowing air flow through the balcony.

AN ANALOGY ON ANOTHER TYPE OF CONCRETE VENT BLOCK AND THE CONCRETE VENT BLOCKS AT PJ TRADE CENTRE

This analogy only discussed on the change of indoor temperature for this experiment, as this paper studies on improving the indoor environmental quality . Based on this study, it can be said that the concrete vent blocks at PJ Trade Centre are able to improve the indoor environmental quality by having the prospect of cooling indoor temperature of the building by at least 10%. The concrete vent block used at PJ Trade Centre allows more airflow than that of this prototype. Moreover, The use of concrete vent block at PJTC is in larger scale to compare with this study.

Vegetation

•  PJ Trade Centre has a landscape plaza with more than 1400 mature trees, 12 Sky Terraces with tall trees, wall creepers and hanging vines. •  Sky Terraces between towers - bring landscaping up vertically and giving its occupants a thrilling experience walking on the steel grating. •  Plaza & wall creepers- environmental friendly and allow the user to feel close to nature, while increasing the natural ventilation around the building, provide shade and act as a filter to cool heated wind.

Conclusion

•  The use of concrete vent block improves the indoor environmental quality as a natural cooling strategy at PJ Trade Centre. •  The thermal mass of concrete allows better cooling towards the occupants during the working hours. •  The orientation of the building helps to support the idea of using concrete vent

block as natural cooling strategy. •  The concrete vent block acts as a shading device which allows airflow to circulate

in the building, thus makes the building naturally ventilated. •  The design of the building using wind scoop effect and stacking effect enhance the ventilation system, thus cooling the building. •  The trees planted all around the building and the wall creepers acts as filtration to cool the heated air.

References

[1] Ratcliff, R. (2014). Properties of Concrete. Retrieved April 17, 2015, from World Business Council for Sustainable Development (WBCSD) website: http://www.wbcsdcement.org/index.php/key-issues/sustainability-with-concrete/properties-of-concrete [2] Boake, T. (2011). Sustainable Design Part Three: The Basic Principles of Passive Design. Retrieved April 20, 2015, from Slideshare: http://www.slideshare.net/tboake/sustainable-design-part-three-the-basic-principles-of-passive-design [3] Architectus. (2013). Sustainability - Natural Ventilation. Retrieved April 15, 2014, fromArchitectus: http://www.architectus.com.au/en/sustainability/articles/natural-ventilation [4] Ng, T. (2013). PJ Trade Centre Damansara Perdana, Petaling Jaya. Retrieved April 17, 2015, from PJ Trade Centre official website: http://www.pjtradecentre.com/about.html [5] Ismail, Z. (Ed.). (2015, February 1). PJ Trade Centre. Architecture Malaysia, 18-25. [6] Yang, D., Sun, W., Liu, Z., & Zheng, K. (2003). Research on improving the heat insulation and preservation properties of small-size concrete hollow blocks.Cement and concrete research, 33(9), 1357-1361.