Cultural Microclimatic Park by HuiYuan_Koh

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Cultural Microclimatic Park The urban park is a place where visitors can enjoy comfortable outdoor space and have enhanced experiences of Chinese culture through the design of the Chinese classical garden. It is located on Little Bourke Street, in the middle of the oldest Chinatown in Australia - Melbourne Chinatown, hence the park will have a role to conserve the Asian cultural heritage. This is explored through designing the park and its atmospheric sensation during the season for major Chinese cultural events such as the Chinese New Year celebration and Mooncake festival; where it could function as event space and provide a comfortable outdoor environment to hold these cultural events.

Our design concepts are based on the Chinese Classical garden that has a strong influence from the Shanshui culture and the Chinese philosophy of Yin and Yang. The Shanshui culture is a cultural phenomenon that is derived from nature. It is the creation of peaceful spiritual shelters by manipulating the natural element of the landscape. Through studying case studies such as the Chinese Garden of Friendship in Sydney, we have extracted a few design principles that follow the concept of Shanshui culture. These concepts and principles are used to create a Chinese aesthetic outdoor space that provides a sense of inner peace for them. The Yin and Yang philosophy inform us that all things are mutually opposing and constraining and we should always keep a dynamic balance of all things. In this design, it is to create a harmony between nature and humans.

By combining the design principles of a Chinese garden and microclimatic design strategies, the park becomes a comfortable space where people are able to enjoy outdoors all year long. It is an urban park that focuses on Chinese culture, microclimate and the community.

According to the reading The Garden of Cool Change (Missingham & Selenitsch, 2000), ’As a placemaking tradition, Chinese gardens aimed to provoke emotional engagement and intellectual reflection – interior and personal rather than collective and social experience.’ The landscape design of the garden takes in consideration the human activities and sensory experience at different seasons and time.

Shanshui culture

Yin & Yang

Natural element

Framed & borrowed view

Extension guide

Rhythm & repetition

Pr i nci pl e s

Design Concepts & Principles

Conce p ts

Introduction

Design Strategies

Water & Rock

Planting Design

Cool Paving

Shading Structure

Lit

tle

ur ke St re

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Climate Data Walk A is a North South axis walk connecting Londsdale Street and Bourke Street. We have shown sections on Corrs Lane, Middle Site and Brien Lane which are Section A-A, Section B-B and Section D-D respectively. The path at Corrs Lane and Brien Lane are relatively narrow and were shaded most of the time by the adjacent building as seen in Section A-A and Section D-D. The narrow lane also results in wind tunnel when there is prevailing North and South wind. This result to cooler environment. Walk B is a East West axis walk connecting Russell Street and Exhibition Street through Little Bourke Street. Section C-C and Section E-E investigate the relationship between the building height and shading. On the site, buildings adjacent on Little Bourke Street are around 1-3 storeys. Although the building provide shades on the pedestrian walk, it does not cover the asphalt road and the pedestrian walk on the south side. Visitor will not feel comfortable during summer during hot day if they were expose under the sun. Section B-B and Section C-C shown the middle site that has a wide empty space. From the onsite recorded temperature, it is observed that the site has a relatively fluctuating temperature between morning and afternoon compared to other spots.

Section A-A

Section B-B

Section C-C

Section D-D

Section E-E

During summer and autumn, the majority of uncomfortable days are due to heat stress and air pollutants as warm dry conditions create favourable settings for heat waves and bushfires. Grass pollen which is of a continental origin is the key discomfort contributor (hayfever) during late spring and early summer. This means during Chinese New Year celebrations - a major Chinese cultural event, people will potentially feel uncomfortable and sick while spending their time outdoor.

The Predicted Mean Vote (PMV) is an indicator for thermal comfort which consider environmental and personal factors. The environmental factors include air temperature, level of humidity, wind speed and direction and average rainfall. A PMV value of 0 means comfort is achieved. In the summer season, there is high outdoor temperature with lower relative humidity. The PMV result is the furthest from the thermal comfort zone. In the winter season, there is a lower air temperature, higher humidity level and lower wind speed, leading to a closer value to the thermal comfort zone. One finding from this is wind can play an important role in affecting the outdoor environment conditions.

This diagram analyze the broader context of Melbourne climate data and social events in Chinatown, it helps to identify the opportunities and constraints of outdoor environment conditions for the proposed site.

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Site Analysis

Through the simulation of walk A and B on the site, we found out that compared to other site points, Middle site has higher wind velocity and solar exposure. In the summer, Little Bourke Street and the Middle Site have very high solar radiation which is 2.5 kWh/m2 when simulated for 3 hours. With the same amount of simulation time, during spring the same site has solar radiation of 0.3-2.0 kWh/m2, during autumn solar radiation is 0.4-0.7 kWh/m2, during winter solar radiation is 0.0-1.0 kWh/m2. In these simulations, we can observe that where there is shade, solar radiation is lower. The narrow laneway such as Corrs Ln and Brien Ln has solar radiation of approximately 0.

Radiation

Human Activity

Proposed site

Wind Direction

We have picked Middle Site to carry out design intervention because of the the problematic environmental condition brought by high solar radiation and relatively high wind velocity. It also plays an important transition point which is adjacent to two main streets. By designing the site as a cultural microclimate park, it has opportunities to revive heritage precinct, promote greenery in urban outdoor space and cultural event activities in the middle of Melbourne CBD zone.

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Master Plan

Design Strategies

Water & Rock Feature Water and rock are the two key features in the design to bring a notion of balance in terms of microclimate mitigation and Chinese culture philosophy.

Planting Design Planting design in the garden provides functions of featuring view and adapting to microclimate in different seasons. The aim is to create a picturesque scenery for visitors and provide shade when needed.

Corr

Shading

s Ln

Designed shading structures will provide shading for people during hot summers and warm air allowed to come through during winters

Cool Pavements

Little

ke r u o B

Permeable pavement could reflect sunlight resulting in a cooler pavement and atmospheric temperature. The water flow under the site during rainy days will also help to carry heat away from the site

St 0m

1.5m 0.5m

3.5m

Winter

Outdoor Furnitures Offering seats for outdoor dining and leisure

Plum Tree Flowers are blooming during winter seasons to create a picturesque scenery

Framing View A focal point of layering view for the whole garden

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Scenarios during Special Events

Rock Garden at night during the festive season.

Water feature used to mitigate city noise, creating a quiet and peaceful space during non feastive time.

Function as event and performance space.

Summer

Outdoor Furnitures Offering seats for outdoor dining and leisure

Arbor Climbing plants provide shading for people seating underneath

Water Curtain Preparing a subtle atmosphere for visitors entering the garden

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Design Strategies

Water & Rock

Water and rock are the two key features in the design. The design idea is based on Chinses philosophy of Ying Yang theory integrated with microclimate mitigation to achieve a notion of balance in the garden. Water brings cooling effect to the south court where it is the most exposed area to solar radiation. It cools down heat in summers and increases humidity to achieve a fresh and cool thermal experience for visitors. And when summer breezes come from south and southwestern, it emphasizes the cooling effect and flow into north court. Rocks in the south court will slow down the temperature change during day and night. During daytime heating from solar, thermal mass in rocks would able to absorb parts of heating, and then releasing the stored heat back to ambient air temperature during nights. It slows the change of temperature and bring a notion of balance for people’s experiences.

Water features on the North Court.

Water Coverage Impacts on Microclimate Mitigation

According to a study of impact evaluation of landscape elements on microclimate and thermal comfort of Lingering Garden in Suzhou, the result states that water body can modify the thermal comfort indicator more than 1°C. ( Yao Xion, 2020)

It shows that the temperature drops with the water area increasing from 25% to 40% was less significant than that from 10% to 25%. It vindicates that there is an upper limit for water body impacted on reduced temperatures.

As a result, the most optimal size of water coverage is 25% which can achieve an effective cooling effect and leaving more space for human activities. In the garden, we decide to apply 25% water coverage of south court’s area for designed water pond.

Misting Sytem ‘Dry Mist’ System To couple with the Urban Heat Island effect from heats in summers, there is a solution of use of misting systems that tap on the principle of latent heat of vaporisation to provide cooling. During hot afternoons where relative humidity is lower, but the original “wet mist’ systems are disadvantageous because only a fraction of the water evaporates, and the remaining liquid produces a wet sensation upon contact, lowering the cooling performance. In the garden, we employ an evaporative cooling system called ‘Dry Mist’ system, which refers to systems which produce ultrasmall water droplets that evaporate very quickly, and do not leave a wet sensation on the human skin upon contact. (K., C., C., & N. ,2019)

Other than providing cooling effect, the misting system that acts as a humidifier also play a role in both the improvement and treatment of allergies symptoms. During pollen seasons in summers, the misting system increase humidity as breathing higher humidity air is one way to relieve the discomfort and symptoms of allergies and reducing inflammation of tissues related to pollen allergy, resulting in providing a quick relief for visitors.

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Rock Garden on the South Court during daytime.

Rock Garden on the South Court during night time.

Rock Garden Design Concept

Notion of Balance

Prevailing Wind

Reserved Wind Tunnel

Water and rock are the two key features in the design to bring a notion of balance in terms of microclimate mitigation and Chinese culture philosophy

The two dominant wind directions are from south and southwestern in summers and autumns, the northerlies in winters had been blocked by buildings

While designing for the orientation and form of the rock garden, the middle part of the rock garden is emptied to provide a tunnel for summer breeze to come through into the north court

Obstacles Free Ensuring there is no objects that blocked the summer breezes from south and southwest, which brings the freshness and coolness into the site during hot summer

Winter

Fresh and cool breezes manipulated by the water pond.

Rocks Rocks help to absorb a part of heat in hot summers, and release the heat back to ambient temperature slowly which slow down the change

Water Water pond helps to cool down the prevailing wind from south in hot summers and increase moisture in the air.

Prevailing winds are from south in the hot summer.

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Design Strategies

Shading

The shading structure are designed and positioned in a way to create an enhanced experience of the Chinese Classical Garden. It is design to frame the view of the featured water pond and rock garden and also to guide the visitor through the garden. The structures are placed along the Little Bourke Street to create a sense of privacy for the park visitors and to separate the park into create regions with different sensory experience. In terms of thermal comfort, the structures are important in providing a cooling resting spot for people, especially during hot summer when the site has long hours of high solar exposure. It is also design with the goal of reducing the strong southernly wind that brings in heat wave during the summer towards the Middle Site. The chosen shading structure consist of a clerestory opening which is an effective passive cooling strategy to induce an air flow, allowing the more buoyant warm air to escape. It also angled to allow winter sunlight to shine on the south side of the shading. Shading structure that create focal points and borrowed view.

Resting spot under the arbor with deciduous climbing plant that allow sunlight into the space.

Park layout has extension guide to provide an enhanced Chinese garden experience.

Outdoor Comfort Shade Benefit Analysis

By using the outdoor comfort shade benefit analysis, which is a diagram shows where the allocation of shade is required, the different roof structure design, and allocation of trees to shade and manipulate. In short, the darker the blue indicates the more demanded areas for shading during the hot season, the darker the red indicates people need more sunshine in winter therefore shading isn’t necessary. The diagram on the right compares the comfort index change before and after shading, in the diagram, the red area during the hot summer season is obviously reduced since the shading is applied and provides a more thermal comfortable environment for people.

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Design Iterations

Chosen

Solid Wall

Structure A

southernly wind

northernly wind

winter

Function as transitional between two space

space

•

Provide a sense of privacy

•

Create framed view and focal point

southernly wind

northernly wind

winter

Pros • Resist strong south wind speed and heat wave direct towards into middle site during summer

Structure C

southernly wind

summer

•

Structure B

northernly wind

summer

winter

Pros • All pros of a solid wall

Pros • All pros of solide wall

•

Provide shade to high solar exposure and solar radiation zone during summer

Cons • Very cold during the winter due to lack of heat and natural light

•

During summer, clerestory opening are angled to provide shade but also allow winter sunlight to reach the south side of the shading structure. Clerestory opening use as thermal heat escape during summer season

Cons • No shade

Clerestory opening Allow southernly wind to flow through and allow warm air to espade, creating a cooler ground level atmospheric temperature.

Vegetation as shading Deciduous climbing plant provide shade during summer and allow sunlight in during winter.

Fully shaded north solar orientation during summer

Cons • Inefficient to reduce the south wind •

Allow only low amount of natural light to pass through

•

Very cold during the winter due to lack of heat

Angled shading roof Roof shade is angled to allow winter sunlight to pass through the clerestory opening, allowing natural light and heat on the south side of the structure.

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Design Strategies

Vegetation

For planting design in the garden, we set criteria for species selection in terms of microclimate mitigation, featuring view and seasonal change to deliver a pleasant sensory experience for visitors.

Plum tree as the focal point on the North Court

Deciduous trees are considered to provide shade most of the time but allow the penetration of sunlight during the winter season to warm up the site. Meanwhile, the summer breeze coming from the south, based on the wind analysis provides an opportunity to utilize the wind tunnel as a medium to spread the scent of flowers, providing a pleasant smell for visitors. All selected species are referred to Royal Botanic Garden and Burnley Plants Guide to ensure the plants are able to grow in the local climate condition.

Lighting on vegetation create a different visual experience for the visitors.

Planting Design Strategies

Spring & Summer Scenario Trees provide shade for people in hot summers and act as green barrier to filter the unpleasant smell from the restaurant beside

Autumn Scenario

Winter Scenario

Wind Tunnel

Deciduous Gingko trees contribute autumn color with foliage interest.

Leaves of deciduous trees falling down in winter, and allow sunlight go through the site to warm up

The scent of the flowers is wafted along by the breeze from south in summers

Planting Design Criteria

Design Simulation Vegetation Solar Analysis

Plants Selection

Ginkgo biloba ‘Princeton Sentry’ Summer

These are solar simulation of selected deciduous trees in Summer and Solar Radiation Analysis Winter, it testifies that shade from tree canopy is demanding in summer, but in winter, shade is not necessary. Group 10_Ahvaz | Hui Yuan Koh 799168 | Zhiyong Pe 1111873 | Liying Tang 825665 | Hongyu Wei 1141893 | Minjie Liang 1010618

Prunus mume ‘Pendula’

Trachelospermum jasminoides

Winter

Selected species will provide functions of featuring view and adapting to microclimate in different seasons

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Design Strategies

Paving

In urban context, most of the urban fabric is covered by pavements. Therefore, the outdoor thermal environment is influenced by the surface temperature of pavements which is most prominent heat sources incident solar radiation. In the garden, we employ cool pavements by increasing permeability which cools the pavement through evaporation of moisture. (D., & D. (n.d.).) A study shows that cool paving reduces pavement temperatures by 19.5°C or more, it is an effective way to reduce solar heat in urban phenomena. (D., & D. (n.d.).) Permeable paving has a longer solar reflectance which the surface temperature is lower. And its permeability helps create water flow underneath to cool heat away (D., & D. (n.d.).). As a result, employing permeable paving in the garden is an effective way to mitigate microclimate and help to achieve a thermal comfort experience for visitors. Entrance view with cool paving and framed view.

Impermeable vs Permeable Pavements Impacts on UHI Rainy Days

Sunny Days

Impermeable

Permeable

Impermeable

Permeable

Rainwater is difficult to permeate due to its importability.

Allowing rainwater to go through which tends to create cooler atmosphere due to evaporation

Impermeable paving has a shorter solar reflectance which results in higher surface temperature

Permeable paving has a longer solar reflectance which results in lower surface temperature.

Rainy Day Due to evaporation, the pervious surface tends to be cooler than the impermeable pavements.

Hot Day Due to longer solar reflectance, the permeable pavements absorb less heat with a lower surface temperature

ABPL90380_2020_NOV | Designing for Heat in the Public Domain

Reference Chris Reardon, D. C. (2013). Passive cooling. Retrieved from https://www.yourhome.gov.au/passive-design/passive-cooling D., & D. (n.d.). Mitigating Thermal/Solar Heat Gains on Pavements and Its Influence on the Environment (9th ed., Vol. 7, Ser. 2015, pp. 34-41, Rep.). Civil and Environmental Research. Jacobs, Stephanie & Pezza, Alexandre & Barras, Vaughan & Bye, John. (2013). A new ‘bio-comfort’ perspective for Melbourne based on heat stress, air pollution and pollen. International journal of biometeorology. 58. 10.1007/s00484-013-0636-0. K., C., C., & N. (2019). Dry mist systems and its impact on thermal comfort for the tropics. Sustainable Cities and Society, 51(101727), issn 2210-6707. doi:https://doi.org/10.1016/j.scs.2019.101727. Retrieved from: http://www.sciencedirect.com/science/article/pii/S2210670719311515 Missingham, Greg & Selenitsch, Alex. (2000). THE GARDEN OF THE COOL CHANGE: A GARDEN IN SUBURBAN MELBOURNE DESIGNED ON CLASSICAL CHINESE SCHOLAR GARDEN PRINCIPLES. Nurse rock microclimates significantly buffer exposure to freezing temperature and moderate summer temperature [Abstract]. Journal of Arid Environments, 177(ISSN 0140-1963). doi:https://www.sciencedirect.com/science/article/abs/pii/S0140196320300537?via%3Dihub Yao Xion, J. Z., Xiyan Xu, Yan Yan , Shibo Sun , Shuming Liu. (2020). Strategies for improving the microclimate and thermal comfort of a classical Chinese garden in the hot-summer and cold-winter zone. Energy & Buildings.