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External Environments

Bernardo Vazquez, Associate

“Using Microclimate Analysis to improve external environments for Hospital Master planning”

5th European Hospital Engineering Conference , Bern Switzerland, 2013.

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Presentation outline

� Human Comfort

� Case Studies

• Liverpool Arena

• Pinderfields Hospital, UK

� Closure

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Analysis of Comfort Conditions (External conditions)

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Analysis of Comfort Conditions - Transition strategy

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Analysis of Comfort Conditions (External conditions)

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Analysis of Comfort Conditions (External conditions)

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Analysis of Comfort Conditions (External conditions)

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Analysis of Comfort Conditions (External conditions)

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Analysis of Comfort Conditions (External conditions)

Temperature & velocity

Temperature & Humidity

Wind velocity

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Analysis of Comfort Conditions (External conditions)

Temperature

Radiation

Wind

Humidity

Clothing

Expectation

Acclimatisation

Activity

Exposure time

Hot Climates

Cooling breezes

Shelter from extreme winds

Cold climates

Protect from cold winds

Evergreen trees

Temperate climates

Balance cooling vs. shelter

Shelter from strong winds

Dependent on activity

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Design Criteria

External activities on site are classified based on their sensitivity. Quantitative assessment

is required to determine the magnitude of the wind speeds and if areas are likely to be

suitable for selected activities.

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1946 Beaufort Scale

1946 Beaufort Scale

0Calm Calm. Smoke rises vertically.

1Light air Wind motion visible in smoke.

2Light breeze

Wind felt on exposed skin.

Leaves rustle.

3 Gentle

breeze

Leaves and smaller twigs in

constant motion.

4 Moderate

breeze

Dust and loose paper raised.

Small branches begin to

move.

5Fresh breeze Smaller trees sway.

6 Strong

breeze

Large branches in motion.

Whistling heard in overhead

wires. Umbrella use becomes

difficult.

7

Whole trees in motion. Effort

needed to walk against the

wind.

Land conditionsBeaufort

numberDescription

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Lawson Criteria– Comfortable conditions

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Lawson Criteria – Tolerable conditions

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Design Criteria

With ICT Methodology developed by TV Lawson from Bristol University

"The evaluation of the windiness of a building complex before construction,” TV

Lawson, London Docklands Development Corporation

• Developed from Beaufort Scale, extending applicability to

environments in and around buildings.

• Widely accepted for this type of study and comparable with

international guidance

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Design Criteria

Comfort & Safety Criteria

CriteriaFrequency of Wind

Speed OccurrencesActivity

Comfort <5% All pedestrian activities

Safety <0.025% All pedestrian activities

The safety criteria correspond to a single occurrence

of about 2-3hours within a year of a value of the mean

hourly wind speed not exceeding 15m/s for the elderly

and 20m/s for the able bodied

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Case Study – Liverpool Arena

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Wind Engineering Process

Site climate Building Effects

Impacts Design

Wind Data

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Site Proposal

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Desktop – identification of possible mitigation measures

Permeable screens that are as tall as the underside of the tree

canopy provide a wind screen for pedestrians on sidewalk while

allowing views

Low level

sculptural screens

will help screen

high speed winds

from the south

Fin like screens will

shelter exits form West

winds blowing down

the street

Low level

shrubs will

increase the

surface

roughness

of the earth

mounds and

slow high

speed winds

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CFD

With Mitigation

Without Mitigation

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Wind tunnel

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In use

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External Microclimate AnalysisFast wind comfort analysis tool for EIA planning

• To provide both qualitative and quantitative expert advice to designers and planners of new

development to ensure comfort and safety of pedestrians as well as regulatory requirements for EIA’s.

• Ability to communicate highly technical solutions and their cost vs. benefits to non-technical

audiences. This helps our clients make desirable spaces with a high retail potential, to generate

revenue.

Annual comfort map

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External Microclimate AnalysisUniversal Thermal Climate Index

• Index used to quantify comfort annually and for specific detailed snapshot

•Maximise value of external spaces for revenue generation such as good retail facilities

•De-risks design to ensure comfortable external spaces, allowing early Master planning

opportunities

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External Microclimate AnalysisExternal Comfort – Cont.

•BH assess the comfort levels against the usage or retail value of external areas for different

seasons and times of the day.

•Starting at early design stages, we look at different Masterplanning options (different building layouts

vs wind, shading, orientation, etc), progressing through detailed design of shelter schemes and

landscaping

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Mean Scenarios

Scenario 2: Canopy Solar Performance

Scenario 3: Permeability/Openness

Scenario 6: Water FeaturesScenario 5: Black Sky Cooling Scenario 7: Planting

Mean Measures

Scenario 4: Increased Thermal Mass

• Six ‘MEAN’ Scenarios explored

• Scenarios 2 to 4 looked at in sequence and the cumulative effects analysed

• Scenarios 5 to 7 are looked at in turn and the potential benefits addressed with reference to the results of scenario 4

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Base Scenario

� The Base Case Scenario assumes that there is

no canopy

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Environmental conditions – Equivalent Temperature via (UTCI)

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Heat exchanges

Q ground

Q Walls

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Heat exchanges

Q ground

Q Walls

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Heat exchanges

Q ground

Q Walls

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Heat exchanges

Q ground

Q Walls

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Canopy performance

� ETFE Canopy added above

the street

� The solar performance of the

canopy improved by reducing

the solar transmittance (g-

value) of the construction

No Canopy Canopy

Transmitted

Reflected

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Canopy Solar Performance – environmental conditions

0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%

Galleria with no canopy roof

Roof material g=0.5

Roof material g=0.4

Roof material g=0.3

Roof material g=0.2

Roof material g=0.1

Slightly cold stress No thermal stress Moderate heat stress Hot heat stress Very hot heat stress Extreme heat stress

59%

59%

58%

58%

58%

54%

g = 0.1

g = 0.2

g = 0.3

g = 0.4

g = 0.5

Base Case

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Canopy Solar Performance – environmental conditions 2

• Improving the g-value reduces the percentage of temperatures within the ‘very hot heat stress’ band. No

significant change to the percentage of hours in the green band

0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%

Galleria with no canopy roof

Roof material g=0.5

Roof material g=0.4

Roof material g=0.3

Roof material g=0.2

Roof material g=0.1

Slightly cold stress No thermal stress Moderate heat stress Hot heat stress Very hot heat stress Extreme heat stress

59%

59%

58%

58%

58%

54%

g = 0.1

g = 0.2

g = 0.3

g = 0.4

g = 0.5

Base Case

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Case Study – Pinderfield Hospital

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Solar - shadow cast

� To Be Updated at Conference

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CFD - UTCI

� To Be Updated at Conference

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Urban Heat Island - 1

� To Be Updated at Conference

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Urban Heat Island - 2

� To Be Updated at Conference

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External Microclimate AnalysisUniversal Thermal Climate Index

•Measurement of annual and detailed snapshot that quantifies comfort

•Maximise value of external spaces for revenue generation

Area 1: 50% shadedArea 1

extreme heat stressmoderate heat stressno thermal stressstrong cold stress moderate cold stress

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Effect of Landscape

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Boston

New York

Chicago

Los Angeles

San Francisco

Belfast

Bath

Birmingham

London

Glasgow

Edinburgh

Manchester

Leeds

Berlin

Copenhagen

Milan

Moscow

Munich

Warsaw

Cairo

Jeddah

Riyadh

Kuwait

Abu Dhabi

Dubai

Beijing

Hong Kong

Mumbai

Global Offices

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