AR1329 Task 1 Report

Group 4-7

Year 2 | Semester 2

BA Arch

Department of Architecture

School of Design and Environment

National University of Singapore

AY2022/2023

Task 1.

Measuring & Experiencing

AR1329 | Climate. Ecology & Architecture

Prof. Heinzelmann Florian

Mr. Joel Lau

Huang Zitao

A0239208A

Xu Chenxiao

A0239094X

Wang Tianyun

A0238022R

Zhang Xuanqi

A0236544A

CONTENTS

SECTION 1 | SITE ANALYSIS

Oasis Terraces

SECTION 2 | 4 CONDITIONS

Forest Park

Aircon Alley

Sealed Surface

SECTION 3 | INDIVIDUAL ROOM

Zitao's Room at PGPR

Chenxiao's Room at RVRC

Tianyun's Room at RC4

Xuanqi's Room at Jurong East HDB

SECTION 1 | SITE ANALYSIS

Oasis Terraces

The new neighbourhood centre and polyclinic at Punggol was envisioned together by, “Serie Architects” and “Multiply Architects” in 2017.

The design concept is to construct a light and open frame that accommodate multiple programs and functionalities, in conjunction with the slopped terrace that knit together the community and the landscape.

Punggol Waterway

50m+ HDB Blocks

Free Green Land

Sitting among high-rise HDB blocks, Oasis Terraces faces the Punggol waterway and link up with the free large green land on its west.

Builing Massing and Design Concept

On the waters edge is an 800sqm sheltered community plaza with a 4-storey-tall column-free clear space.

Rendered view of 11am on Jan 27, 2023, the date of site visit

The C-shape massing creates a self-shading effect for the central "courtyard".

The central green area slopes down towards the waterway, allowing for light and air to penetrate the building.

Water Playground

Hammock Deck

Jumping Water Jets

Garden Cabana Deck

Rain Garden

Polyclinic

Community Plaza

Foodcourt Shops

Annual Sunpath and Shadow Patterns

Oberservation and Findings:

September 1700

In March and September, the sun is exactly above the Equator and travels along a similar sunpath. The terrace and roof experiences more direct and stronger sunlight, and are expected to have higher luminance and temperature. Throughout the year, the east facade of Oasis Terraces is shaded by its neighbouring buildings in the morning. In June, when the Earth's north pole is at its maximum tilt, Oasis Terraces's west facade has a longer exposure to the sun.

Building Orientation and Monthly Solar Exposure

Due to the building's orientation, the west facade of Oasis Terraces is heated more by the afternoon sun in the first half of the year (from March to September). Especially in June, from 4pm to 6pm, the west facade is fully exposed to the sun.

The south side of the building is connected to Oasis LRT station. Yet in December, there would be some sun glare at noon.

The presence of neighboring HDBs blocks Oasis Terraces and prevents it from the morning sun glare especially in the second half of the year (from September to next year March).

Facade Material Consideration

East Facade

As the neighboring buildings cast shadow on the east facade of Oasis Terraces, we expect it to be have less sun glare. However, the annual glare simulation shows otherwise. The luminance level is still too high to be tolerable. Thus there is still a need for sun shading.

Both east and west facades actually use concrete wall rather than full glazing for a more comfortable working environment of 500 lux. The simulation of both facades with the solid concrete wall justifies its effectiveness.

West Facade 1800

East facade with full glazing

East facade with solid concrete wall

Annual wind rose shows that prevailing winds come from northeast and south, which correspond to Oasis Terraces' orientation and typology. Together with the south wind, it appears that cross-ventilation is likely to form to cool the entire atrium.

Thus we hypothetise that Oasis Terraces is designed such that the slope increases wind velocity and drives air flow especially at the ground floor.

January wind direction tallies with site visit measurements and experiences.

Fluid Dynamics Analysis

In order to verify our hypothesis on the massing strategy, we compared the terrace slope with a void and a rectangular box on the site location respectively.

Test 1: No building on the existing terrain

Test 2: Building massing as a 6-storey-high flat rectangle

Observation: Wind speed increases dramatically and abruptly around the borders of the rectangular massing.

Test 3: Actual design, which contains a slope

Top View (left)

Isometric View (right)

Observation: The increase in air velocity along the terraces is more gradual. A low pressure zone down the atrium is also created to draw air in, evident in the less dense tracing lines that envelope the rectangular massing.

Conclusion: The slope facilitate air flow and venturi effect is set up on the ground floor.

Measurements at 12 Locations

Level 6 (Rooftop)

East Corridor

Temperature: 28.5°C

Relative Humidity: 70.9%

Wind Speed: 1.2-2.5m/s

Luminance: 35 klux (10 klux under the shade)

Level 6 (Equipment room)

Along South Corridor

Temperature: 30°C

Relative Humidity: 68.9%

Wind Speed: 2.1m/s

Luminance: 7831 lux -69 klux

Level 6 (Rooftop)

East End, towards the River

Temperature: 30°C

Relative Humidity: 68.2%

Wind Speed: 2.3m/s from the river

Luminance: 16.7-41.1 klux

Level 6 (Rooftop) Gym, West Side

Temperature: 31.4°C

Relative Humidity: 62.8%

Wind Speed: 0.5m/s

Luminance: 4779 lux -53.6 klux

Level 6 (Rooftop)

East Garden

Temperature: 29.8°C

Relative Humidity: 66%

Wind Speed: 3.9m/s

Luminance: 10.7 klux

Level 6 (Rooftop)

Sealed Surface, West End

Temperature: 31°C

Relative Humidity: 61.4%

Wind Speed: 2.4 -5.5m/s

Luminance: 61.4 klux

Level 5

East Corridor

Temperature: 30°C

Relative Humidity: 63%

Wind Speed: 1.2m/s

Luminance: 500 lux

Level 3 (LRT Entrance)

Sheltered Sealed Surface

Temperature: 28°C

Relative Humidity: 61.4%

Wind Speed: 0.6m/s

Luminance: 36 klux

Level 5 (Terrace) Water Playground

Temperature: 29.5-31°C

Relative Humidity: 70%

Wind Speed: 2.3 -3.3m/s

Luminance: 60 klux (20 klux under the trees)

Level 4 (Terrace)

Rain Garden

Temperature: 30°C

Relative Humidity: 65%

Wind Speed: 4m/s

Luminance: 20 klux

Level

Temperature: 27°C

Relative Humidity: 71.5%

Wind Speed: 1m/s

Luminance: 100 lux

Level 1 (Atrium)

Community Plaza

Temperature: 26.7°C

Relative Humidity: 70.7%

Wind Speed: 1.5m/s

Luminance: 13.4 klux

2 (Staircase) towards Shopping Mall

Radar Diagram

In order to make climatic data more visually readable and easier to understand, we have created radar diagrams and defined five dimensions.

The four measurable dimensions are luminance, wind speed, temperature and humidity. The fifth dimension is green-to-sealed surface ratio. It is estimated and added so as to differentiate data collected from green space and sealed man-made visually.

Being inside and outside the community plaza have different experiences. Near the river bank, the wind speed is higher and temperature is lower.

The radar diagram is meant to describe the differences visually using shapes or patterns.

The sets of data collected at Oasis Terraces tally with the general environmental condition in Singapore, where better natural ventilation is needed for optimal comfort. In other words, higher wind speed is needed to lower the high humidity level.

Among all the locations, rooftop park and gym are closest to the comfort zone. Here, a link between activity and choice is location is drawn. The rooftop with good natural ventilation fulfill the requirements for exercising, to bring in fresh air and take away excess heat and water vapor.

Increase in Relative Humidity Increase

Purple Squares: Singapore's Condition

Rooftop Garden and Gym

Climate-Responsive Design Strategies

Fixed Shading Devices --- Effective

Oasis Terraces has a characteristic and consistent use of pergola on its rooftop as a replacement of conventional fully-covered shelter.

Although not protective from the rain, such device can reduce sun glare up to 80% based on measurements.

Gym and east garden are the top two most comfortable places among all, largely due to the pergola that provide shade and also facilitate air flow.

The design leverages on the high wind speed at rooftop to evaporate humid air generated at gym and greeneries.

Mobile Shading Devices --- Unsatisfactory

Wall are recessed to create corridor or balcony so as to reduce sun glare. Yet the additional layer of translucent black roller blind makes the space gloomy and somewhat depressing.

To improve, operable louvres could be used to cature the beauty of light and shades.

Atrium or community plaza does not perform as good as we expected. The 4-storey high space is stuffy and warm because the full-height glass panel between plaza and terraces hinders the air flow.

A possible solution is to use monsoon window to replace the glass, so that the plaza is protected from rain and has good ventilation.

Rooftop Sealed Surface Rooftop Gym

Rooftop Garden at Southeast Corner

Rooftop South Corridor

Level 5 East Corridor

Level 5 East Corridor

Ground Floor Atrium

Ground Floor Atrium

Annual Average Luminance of Selected Regions: 26882 lux

Annual Average Luminance of Entire Rooftop: 32156 lux

Through it is still bright at rooftop especially in the afternoon, the pergola shading devices have effectively reduce a significant percentage of sun glare, as evident in the clear color distinction between the shaded and unshaded areas.

Rooftop Garden at Southeast Corner

Rooftop Sealed Surface

Rooftop Gym

Rooftop South Corridor

Climatic Performance Test @Terraces

Self-shading effect of the C-shape massing is justified, as shown in blue regions. While unshaded terraces appear very bright and hot in the simulation result, the actual situation is better with the trees.

Recession in facade reduces a portion of sun glare but black blinds are still needed mainly in the afternoon. The necessity of using blinds is illustrated on the left, as they lower the brightness by over 80%.

Annual Average Luminance without Blinds: 10717 lux

Annual Average Luminance with Blinds: 1871 lux

Jan 0900 with blinds half-open

Jan 1100 with blinds half-open

Jan 1600 with blinds half-open

Annual Average Luminance without Blinds: 9438 lux

Annual Average Luminance without Blinds: 7733 lux

Inside and outside the plaza has a large difference in luminance level. Thus the plaza may feel dark due to such comparison, though it is mostly above 1000 lux. Similar to corridors, blinds are incorporated but this time the shading effect of blinds is less obvious as they can only cover two fifths of the height.

SECTION 2 | 4 CONDITIONS Forest

Park

Bishan Park

Aircon Alley

Little India Chinatown

Sealed Surface

Bayfront

Bukit Timah Nature Reserve Pulau Ubin

Forest 1 Aircon Alleys

Sealed Surface Forest 2 Park

Forest @ Bukit Timah

Windy and Drizzly, Measured on Jan 25 Slightly Rainy, Measured on Jan 28

Forest @ Pulau Ubin

Park @ Bishan AMK

Overcast, Measured on Jan 18

Aircon

Alley @ Little India

Sunny, Measured on Jan 27

Sealed Surface @ Bayfront

Sunny, Measured on Jan 27

Aircon Alley @ Chinatown

Rainy, Measured on Jan 23

Rainy, Measured on Jan 23

Comparison with Characteristic Environments

On the psychometric chart, the data points of Oasis Terraces largely overlap with those of park, aircon alley and sealed surface. They stray away from the forest data points, which are closer to the comfort zone in general.

However, that does not imply that Oasis Terraces and these locations give visitors the same sensation. Based on our physical experience, the rooftop of Oasis Terrace, for example, was much more cooling and comfortable than the sealed surface even though the data points overlap. This is because the rooftop of Oasis Terraces has good natural ventilation, which improved the comfort level there. In other words, the intervention suggested by the psychometric chart is already in place.

Chenxiao's Room at

SECTION 3 | INDIVIDUAL ROOM

Zitao's Room at PGPR

Tianyun's Room at RC4

Xuanqi's Room at Jurong East HDB

Tianyun's Room at RC4

Where is RC4?

Residential College 4 (RC4) is located at the north end of NUS University Town. It is next to College of Alice and Peter Tan (CAPT) and former Yale-NUS College. Surrounded by many low-rise buildings including New Town Secondary School, RC4 is rather exposed to direct sunlight, hardly shaded by neighboring buildings.

My room located at level 9 is usually bright and hot in the afternoon. Thus this report focuses on the afternoon sun glare analysis.

CAPT

Low-rise Houses

High-rise HDBs

New Town Secondary School

Yale-NUS

When is RC4 shaded by neighboring buildings?

RC4 is slightly only shaded by Yale-NUS and CAPT in the late afternoon about 1.5 hour before sunset.

Why does my room have an overhang?

Morning sun is only observed at CAPT side not at RC4.

RC4: North and south facades are not exposed to low-angle sunlight, thus only has overhangs.

Tembusu College: Half-Surrounding Shading to protect from the sun glare in the early morning and late afternoon

Each overhang has a specific width of 760mm, which is roughly half of the full height of the window.

My Room at Level 9, south-facing

CAPT Tembusu College

Comparison with Tembusu College shading devices Similar location but different orientations

Where is my room?

Residential College 4 Level 9 Floor Plan

My Room (Single Corridor with AC)

Current Residential College 4 (RC4)

Current College of Alice and Peter Tan (CAPT)

Why does the wind close my door only in the second half of the year?

Can I not close my window when it rains?

The diagram shows Level 9 layouts and wind direction in the first half of the year. In the second half of the year, the wind direction reverses (from south to north instead). When the south wind is heavy especially on rainy days, it can shut the door of my room.

The wind direction also affects the direction of rain. In other words, from January to June, even if I do not close my window, the rain would not be blown into my room, whereas from June to December, I have to close the window otherwise my bed would be wet.

Suites usually have their doors closed, so cross-ventilation mainly occurs in the corridor.

Where should I take the measurements?

4. Door

Measure with the door open to understand the air flow and ventilation. The measurement also serves as a comparison between indoor and semi-outdoor environments.

2. Bed

Although I spend less time here during daytime (7am7pm), this is an important location to evaluate its comfort level.

Three layers of sun-shading devices:

1. Desk

This is a place where I spend most of my time. It is expected to be the most comfortable spot as the fan is directly above and there is a good distance from the window.

3. Window Brings in lighting and wind. It is where the shading devices start to function.

2600 mm

3000 mm

Measurements are all taken at eye level which is about 1200 mm from the floor.

(1)

(2)

(3)

(3)Rollers Blind (mobile)

(2)Double Glazing Windows

(1)Overhang (fixed)

Why does my room feel cooler on sunny days but warmer on rainy days?

On sunny days single ventilation driven by the ceiling fan works better than cross ventilation driven by wind because of the L shape corridor.

As hot air is less dense and rises, the fan can effectively speeds up air flow, thus it works better than wind.

However, on overcast days when the ex terior, meaning the corridor or outside the window is much cooler (about 2°C) than the interior, 1 and 2 which are in the middle of the room are warmer than 3 and 4.

Is my room brighter and warmer than the corridor?

Annual average luminance of accessible corridor at eye level (1200 mm): 1048 lux

My room with blind fully open

My room is generally bright with blinds fully open (on sunny days), but the sun glare is largely imperceptible. Yet, I have the habit of leaving my blind half open to achieve a comfortable brightness level for working and resting (around 300 lux).

How come recently my room is significantly hotter in the afternoon?

In the afternoon, due to the orientation of the building and the lower sun angle, sunlight is converged to a point between the desk and the bed that is super hot.

My Experiences with the Early-morning and Late-afternoon Sun

As sun glare mostly occurs in the early morning or late-afternoon due to the low sun angles, it seems that the beauty of sunrise and sunset is overlooked. For me, they are meaningful and special moments that mark the start and end of my day. They decorate my room, every day, so that my room is truly livable, not only in climatic aspects, but also in a psychological way.

Watching the shadow of my plant gradually fades away as the sun rises is a pleasant and soothing experience.