part 3 – energy and atmosphere -...

FALL 2013// 48795 A2// LEED: Green Design

& Building Rating in a Global Context SINGAPORE GREENPLAN RATING SYSTEM

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PART 3 – ENERGY AND ATMOSPHERE

SGEA3.1// WHOLE BUILDING PERFORMANCE (2 Options)

Option 1 – Whole Building Simulation Modeling and Analysis

Option 2 – Prescriptive Compliance Path

In Singapore, commercial buildings account for about 31% of the nation’s electricity consumption and

including households, this number increases to about 49% (BCA 2010). From Figure 1 below, it can be

seen that commercial buildings have significantly higher EEI (energy efficiency index); a normalization

the building industry in Singapore uses when comparing the energy usage intensity of different

buildings and is defined by the equation below (BCA). Of the energy consumed by a typical

commercial building, about half is due to air‑conditioning and two fifth attributed to lighting and

mechanical ventilation (Figure 2). Since the intent of this section is to reduce and optimize energy

consumed by a building, the focus would be on measures directed towards energy savings in the areas

of air‑conditioning and mechanical ventilation and lighting without compromising Indoor

Environmental Quality.

Reason for 2 Options

With rapid advances in technology,

building designs and systems are

becoming increasingly complex as with

the evaluation of its performance. With

the many interactions between different

performance indicators, a prescriptive

approach may not be able to effectively

evaluate the performance of a building.

Instead, a performance based approach

using whole building energy simulation

programs such as EnergyPlus, IES‑VE

and e‑QUEST to simulate reductions in

whole building energy consumption

would be more meaningful (Turiel,

Boschen et al. 1984). However, whole

building energy modeling is difficult,

requiring many inputs which may not

be available or are difficult to attain.

Hence, to encourage building owners to



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gradually move towards a performance based evaluation, compliance to this standard in terms of

Energy Efficiency can be achieved either using a prescriptive method (Option 2) or through whole

building energy simulation (Option 1).

Option 1 – Whole Building Simulation and Modeling



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Option 2 – Prescriptive Compliance Path

In Singapore, about 52% of energy consumed by a typical commercial building is for air conditioning

(Lee, Schafer et al. 2004). The energy consumed by the cooling system depends on the amount of heat

gained into the building which in terms depends on the resistant/insulation provided by the building

envelope. This is expected considering that Singapore has heating and cooling degree‑days (base

18.3°C) of 0 and 3537 respectively (ASHRAE Fundamentals – 2009). The building envelope therefore

plays an important role, acting as the modifier between the indoor space and the outdoor environment,

directly influencing the energy requirements and thermal comfort within the building (Guan 2006).

Furthermore, improving the building’s envelope thermal performance can also reduce peak load, thus

reducing system sizes.

Having efficient air‑conditioning systems is crucial to reducing a building’s overall energy

consumption. For instance, by replacing its 15‑year‑old chiller, Republic Plaza was able to reduce its

energy consumption by 17.5% (BCA 2012). This translates to about 4,000,000kWh of energy and

approximately $870,000 savings for its owner. In addition to this increase in efficiency, the owner was

also able to gain an additional 200m² of rentable space, which was initial taken up by the previous

chiller.

Objective

The intent is to encourage the reduction of energy consumption before technological solutions are

applied to eliminate wasteful usage.

Pre-Requisite

• Air conditioning equipment includes:

o Chillers;

o Chilled‑Water Pumps;

o Condenser water pumps;

o Cooling towers

o Air Handling Units

o Fan Coil Units

o Direct –Expansion (DX) unitary air‑conditioners / condensing units

• All air conditioning equipment shall meet the minimum efficiencies specified in SS 530:2006

(Singapore Standard for Energy efficiency standard for building services and equipment).

• The ventilation rates of these systems shall comply with SS CP 13 – Code of Practice for

Mechanical Ventilation and Air‑Conditioning in Buildings

• To ensure good thermal comfort, it is required that air‑conditioning systems be designed to

provide consistent indoor temperature between 22.5 to 25.5°C and relative humidity less than

70%

• Rating conditions for air conditioning equipment shall be as follows:



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o 35°C Entering Water Temperature or Dry Bulb Outdoor Air Temperature for Air Cooled

Condensers

o 29°C Leaving Water Temperature

o 24°C Wet bulb Outdoor Air Temperature

Rating System



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Calculation Equation

Example



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SGEA3.2// NATURAL VENTILATION & AIR QUALITY

Reason

Air‑conditioning typically accounts for about 50% of a commercial building energy consumption in

Singapore (BCA 2010). This is due in part to the Singapore’s hot and humid climate. However, before

trying to improve system efficiencies, passive designs should first be considered to prevent energy

wastage. One way to reduce this is to design for natural ventilation to reduce consumption when

outdoor conditions are favorable. These air movement not only help reduce energy consumption by

reducing the need for air conditioning and mechanical ventilation but also helps to (BCA 2010):

• Reduce heat island effects in dense urban areas

• Improve human comfort within occupied spaces

• Improve indoor air quality

In Singapore, the prevailing wind is in the north to north‑east direction (Northeast monsoon season)

and south to south‑east direction (south‑east monsoon season) (BCA 2010). Hence designers should

take advantage of this fact by orienting buildings in these directions to encourage cross ventilation.

Objective

The intent is to encourage the reduction of energy consumption using passive design alternatives

before technological solutions are applied to eliminate wasteful usage; and to encourage the use of

better energy efficient air‑condition equipment to minimize energy consumption and equipment sizes

without compromising on indoor thermal comfort and air quality



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Pre-Requisite

• If designing for natural ventilation:

o Operable windows shall be provided to allow for natural ventilation as well as to allow

flexibility to use filtration system provided by mechanical systems where outdoor air

quality is bad

o The ventilation simulation shall be carried out in accordance with the assumptions and

methodology stated in Annex C of the Code for Environmental Sustainability of

Buildings (BCA 2010). The CFD modeling shall be carried out using software that is

capable at minimum of the following:

! Solving Navier‑Stokes fluid flow equation for a three‑dimensional

incompressible flow at steady state on a body conforming computational grid

! Turbulence modeling using the standard k‑epsilon turbulence model coupled

with standard wall function



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Rating System



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SGEA3.3// DAYLIGHTING

Pre Requisite – SGST 1.2 Views and

Daylight

Reasons

Daylight autonomy can be easily achieve even with

blinds due to the tropical climate conditions Singapore

experience all year round (Grobe, Wittkopf et al.).

Daylight provision therefore not only proves to be a

useful sustainable resource not only for supplementing

artificial lighting but also for improving indoor

environmental quality. According to BCA (2010), the

presence of adequate daylighting has also been shown

to be both beneficial to artificial lighting consumption

and improved occupant health and well‑being.

Objectives

The intent is to encourage the reduction of energy

consumption due to artificial lighting before

technological solutions are applied to eliminate

wasteful usage.

Pre-Requisite

Daylight sensors are to be installed at locations providing where daylighting is designed for to

eliminate unnecessary daytime use of electric light.

GreenPlan enforces the use of lighting simulation software, such as Ecotect, for lighting assessment. Other simulation tool is acceptable as long as all required factors and calculation are calculated in the report.

GreenPlan requires a clear lighting plan layout within the report. All lighting specifications must be included either as a separate or combined document.



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Rating System



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SGEA3.3.5// ARTIFICIAL LIGHTING

Reasons

Artificial lighting consumes about 20% of whole building energy consumption, the next highest energy

consumer in commercial buildings after air‑conditioning and mechanical ventilation (Ho 2012). By

shifting to electronic ballast and replacing conventional light fitting with energy efficient bulbs and

replacing boilers with heat recovery systems, The Regent Singapore (Hotel) was able to reduce their

energy consumption by 26% (NEA). Hence to reduce energy consumption in buildings, it is essential

that artificial lighting design be addressed.

Objectives

The intent is to reduce energy consumption by artificial lighting while maintaining sufficient lighting

levels suitable for the intended task

Pre-Requisite

To earn credit under this category building must meet the requirements for artificial lighting specified

in SS 530:2006 (Singapore Standard for Energy efficiency standard for building services and

equipment). This is to ensure lighting levels provided within the buildings are sufficient for the

intended task and not compromised to reduce the building’s lighting power density.

Rating System



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SGEA3.4// VENTILATION IN

CARPARKS

Reasons

With 1 in 10 Singaporeans owning a car, the total

number of motorized vehicles within the small island

sums up to approximately 1 million. Buildings need to

cater to the existing number of motorized vehicles

without jeopardizing the health and safety of

occupants

Objectives

Utilizing an energy efficient ventilation system to

provide sufficient fresh air and prevent accumulation

of toxic gas from exhaust by installing adequate

supply/return duct. GreenPlan minimizes the number

of points attainable relative to Greenmark as to

discourage the stress put into car parks space.

Rating System

Source: Energy Market Authority (2011), Energizing our Nation: Singapore Energy Statistics

CO sensor should be installed in enclosed mechanically ventilated caraparks.



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SGEA3.5// EFFICIENT ESCALATORS & ELEVATORS

Reasons

According to Hong Kong EMSD Guideline on Energy Audit, elevator and escalators make up 11% of

non‑residential energy consumption. The amount of energy spent for introducing newer technologies

with occupancy sensors switch that allow for sleep mode can significantly reduce energy consumption

of these appliances.

Objectives

Install sensor switch escalators as to reduce energy load from the typically energy intensive appliances

Install energy efficient elevators such as AC variable voltage and variable frequency (VVVF) motor

drive; and energy efficient features such as sleep mode.

Rating System

Implementation of sensor switch should be implemented for all non-residential buildings.

Energy efficient elevator, such as regenerative drive, can potentially save approximately 1300kWh/year.



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SGEA3.6// ENERGY EFFICIENT FEATURES

Reasons

With increasing advancement in technological systems in

HVAC, Lighting, Building Material and Control industries,

energy efficient features becomes more prevalent. According

to an article in Global Energy Initiative, Singapore’s green

project has increased from 17 in 2005 to a 1,600 in 2011 (Chiao

2011). As a result, energy efficient features become much more

reliable and accessible to many new construction projects.

Objectives

Install energy efficient features which are innovative and have

positive environmental impact in terms of energy saving.

Energy efficient features include the following: heat recovery

devices, thermal insulation or cool paints, occupancy sensors,

vertical greenery system for exterior façade, gas water heater,

clothes drying facilities, skylight or sun pipes, and ductless

fans. Other innovative system that is not listed will be

evaluated by the organization for any accreditation with the

provision of sufficient tender specification and performance

report.

Skylights can be accounted as an energy efficient feature. Glazing of skylights must follow ASHRAE 90.1 standard for climate zone 1.

Heat Recovery System

Vertical green wall façade will only be credited when implemented in proper orientation (east and west)



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Rating System



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SGEA3.7// RENEWABLE ENERGY

Reasons

In 2010, around 79% of Singapore’s electricity

was generated from natural gas, and another 19%

from petroleum products such as fuel oil and

diesel. The remaining 3% was generated through

renewable sources such as biogas, municipal

solid waste and solar (Energy Market Authority

2011). Greater investment needs to be done if the

country hopes to attain a 35% (2005) reduction in

energy use intensity (EUI) by 2050.

Objectives

Install renewable energy harvesting systems such

as photovoltaic (PV) panels, wind turbine within

the building design. Other external

implementation includes enrolling for alternative

energy source such as utilizing district cooling or

enrolling for bio‑waste recycling system will

allow for partial accreditation.

Rating System

According to Renewable energy only made up 3% of Singapore’s total energy consumption.

Singapore rarely integrates energy generation systems in buildings, but there are many external sources that is available as an alternative source of energy.



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Calculation and Point Allocation Energy calculation will be based on expected energy consumption for new building constructions.

Use the building’s annual energy cost, calculated in SGEA 3.1 based on building simulation EUI;

otherwise use the U.S. Department of Energy’s Commercial Buildings Energy Consumption Survey

(CBECS) database to estimate energy use and cost.

For Building Integrated Renewable Sources (a)

Percentage Renewable Energy (Integrated) Points

1% 1

3% 2

5% 3

10% 5

>15% 15

For External Renewable Sources (b)

Percentage Renewable Energy (External) Points

1% 1

3% 2

5% 3

10% 5

>20% 10



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SGEA3.8//

TESTING AND COMMISIONING

Reasons

Current Greenmark standard does not include

any testing and commissioning within its criteria,

hence with the rapidly increasing number of

construction projects, more awards are given too

leniently without considering the maintenance of

proposed standards. GreenPlan proposed that

testing and commissioning is necessary for case

study and performance tracking purposes.

Objectives

Commissioning the electrical and mechanical

systems to ensure the impact on energy use of the

systems is adequate, the systems performance is

as specified and the systems operation is as

intended.

Increasing trend in new construction demand addresses the need of testing and commissioning. Source: Building Construction Authority 2011

Commissioning is a potential cost and energy saving method.



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Rating System



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SGEA3.9// OPERATION AND MAINTENANCE

Reasons

GreenPlan stresses on building operation and maintenance and ensure accreditation is maintained.

Building system has to be updated accordingly to retain awards. Operation and maintenance need to

be kept according to data attained from testing and commissioning. Tuning or replacement needs to be

carried out if system falls under 10% of the initial testing data.

Objectives

GreenPlan stresses on building operation and maintenance and ensure accreditation is maintained.

Building system has to be updated accordingly to retain awards. Operation and maintenance need to

be kept according to data attained from testing and commissioning, hence enabling building operators

to implement the design intent and to monitor and maintain the performance of the building. Tuning

or replacement needs to be carried out if system falls under 10% of the initial testing data.

Rating System



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SGEA3.10// METERING AND MONITORING

Reasons

Although Singapore has a strict metering and sub‑metering code under Energy Market Authority,

there is no disclosure or reports on recorded data. GreenPlan aims to publish these data to raise

awareness of proper metering and monitoring. Since building value will be affected if published data is

inadequate to what was initially tested, the criteria will serve as a motivation for maintaining

performance. New York city for instance initiated the Greater Buildings Plan in 2009, which includes

the benchmarking and disclosure of building energy performance and water consumption. The city

predicted a $700 million savings annually in energy cost from the policy (BuildingRating.org 2013).

Similarly, GreenPlan hopes to create such incentive to achieve greater energy savings.

Objectives

Enable building operators to measure, monitor and develop measures to improve the performance of

the building’s engineering systems, particularly concerning energy use. Building performance and

annual consumption will be recorded and published to the GreenPlan website, for accreditation and

awards and consequent renewal.

Although Singapore has voluntary disclosure for

multi‑family residential buildings, non‑residential

buildings are not subjected to the disclosure and

benchmarking policy. GreenPlan aims to add this

incentive to push the implementation of energy

disclosure and benchmarking within the non‑

residential buildings.



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Rating System



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SUMMARY OF ENERGY AND ATMOSTPHERE

PART 3 ENERGY AND ATMOSPHERE POSSIBLE POINTS

SGEA 3‐1 WHOLE BUILDING PERFORMANCE 30

SGEA 3‐2 AIR CONDITIONING EQUIPMENT, NATURAL

VENTILATION & AIR QUALITY 13

SGEA 3‐3 DAYLIGHTING 9

SGEA 3‐3‐5 ARTIFICIAL LIGHTING 12

SGEA 3‐4 VENTILATION IN CARPARKS 5

SGEA 3‐5 EFFICIENT ESCALATORS AND ELEVATORS 2

SGEA 3‐6 ENERGY EFFICIENT FEATURES 12

SGEA 3‐7 RENEWABLE ENERGY 30

SGEA 3‐8 TESTING AND COMMISIONING 3

SGEA 3‐8‐5 OPERATION AND MAINTENANCE 3

SGEA 3‐9 METERING AND MONITORING 3

Total 122

Since 2005, Singapore expects to reduce building EUI by 35% by 2030, however 2012 data

shows that EUI is reduced by approximately 10% (EMA 2012). Although Greenmark building has

increased exponentially since its conception in 2005, the current standard might be too low for

the projected goal. GreenPlan allows for more a stringent rule by introducing optional

assessments that involve using building simulation tools to increase accuracy and credibility of

expected energy performance.

The existing BCA Greenmark standard puts a lot of emphasize in energy and atmosphere and

presented a great detail in terms of calculation and method of assessment. The GreenPlan

system adapts the existing standard but additionally include the option of using building

simulation tool to encourage performative-based design. As seen from the table, the potential

for scoring points are higher when building simulation is implemented for whole building

performance and natural ventilation assessment. GreenPlan also made building simulation to

be a compulsory tool for lighting assessment.

The optional point also allows for flexibility in choosing various HVAC system, but the points

distribution encourages for the best system. Hence there is also a marginal difference in

potential points for air-conditioning assessment.

GreenPlan decides to add three other possible accreditations for commissioning, operation

and metering. These factors are important especially in correlation to the way GreenPlan

Award functions. These factors will be used to keep track of the building’s consumption thus

enabling the organization to reward the building according to its tested performance.

part 3 – energy and atmosphere -...

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