Sequence of the Presentation Architect’s Perspectives in ... · • Sustainable & Green Retrofitting • Bioclimatic Retrofitting (Naturally ventilated, solar heated/ cooled, well

AshokAshok Kumar Kumar Senior Principal Scientist &Senior Principal Scientist &

Head, Architecture & Planning Head, Architecture & Planning CSIRCSIR--Central Building Research Institute, Central Building Research Institute, RoorkeeRoorkee

Architect’s Perspectives in Green Retrofitting of Existing Buildings

September 6, 2014

International Conference – Green Existing Buildings, IGBC & CII

• Background - Existing Building Stock • Challenges, Opportunities & Perspectives –

Architects• Green Buildings & Green Retrofitting -Define• Identifying Attributes / Approaches – Green

Retrofit• Concluding Remarks

Sequence of the Presentation

CSIR-Central Building Research Institute, Roorkee

India has about 27.87 Billion sqm. (2.787x10 sqm) of

existing building stock as of today.

Retrofitting Existing Buildings into Green can help address National issues like Energy & Water Efficiency, conserving the natural resources,

handling of wastes etc.


Existing Buildings Stock

Buildings use about 50% of all the energy produced in our planet during operation for heating, cooling, lighting and also during building construction (ERG et al.1999).

Buildings also use about 42% of Water and 50% of raw materials.

Major part of this consumption is directly related to buildings use.


Existing Buildings Stock

About 50% Air-Pollution, 42% GHGs, 50% Water Pollution,

48% Solid waste, and 50% Chlorofluorocarbons (CFCs).

In turn they are

responsible for

Break – up of Energy Consumption in a Building

CSIR-Central Building Research Institute, Roorkee CSIR-Central Building Research Institute, Roorkee

Until the early 20th century, the only way to control the indoor climate was through passive

strategies. (Hartog, 2004).

The evolution of new technologies and the development of artificial systems for lighting, and air conditioning equipment and the availability of cheap energy made the architects & engineers ignore the climatic characteristics, resulted in

dependence and indiscriminate use of such systems.

Existing Buildings

Some Solutions to these Challenges

Green Buildings, Retrofitting Existing Buildings& Sustainable Cities

Challenges


Water ShortageClimate Change Energy Shortage Urbanizat ion

Challenges

Conservation of Natural Resourcesv 3 billion tons of limestonev 13 billion tons of aggregates

Climate Change (Green House Gas Emissions)Need to reduce “greenhouse” gas emission to combat global warming

v 6-7% of the World CO2 emissions from cement productionvOne ton of cement produces ~0.9 ton of CO2vCement production is highly energy intensive process.

Construction – the largest consumer of Non-renewable Resources


Green Buildings

ASHRAE Standard 189.1 -describes the High Performance Green Building as - designed, constructed and capable of being operated in a manner that increases environmental performance and economic value over time.



Susta inable

GREEN

Ecological Performance / Per formative

Relationship in Greenness – Architect’s Perspectives

Conceptual Framework

for Measuring

the “Greenness

of Architecture”


Sustainability, Ecology & Performance Requires

• Elements (Technology & Materials) - E

• Resources - R

• Environmental – Env

No. of Attributes

Measuring Green

For example: Building can be completely or barely sustainable or un-sustainable depending upon the

number of attributes it possesses within each of the sub-categories – EREnv.


Sustainable

• Elements (Technology & Materials) – Durable, Economical, Recyclable, Low -Maintenance etc.

• Resources – Onsite conditions, Cost –effectiveness, Accessibility, Natural Forces etc.

• Environmental – Healthy, Habitable, Social, Safety & security etc.

AttributesMeasuring

Green


Elements Resources Environment

Clean ( non pollutant /

low emission)

Resources share Pollution (air/ water/ land)

Earth resources Soil/ landscape Global stewardship

Biodegradable Site selection Biodiversity

Low – embodied energy

Water resources and use

Land use

Renewable Waste management (low solid waste)

Ecological - Measuring Green

The main source of GHG emissions from buildings is energy consumption

Energy is consumed duringi Manufacturing of B.Ms

(‘Embedded’ or ‘Embodied Energy’) ii Transporting the materials from

production plants to building sites (‘Grey’ Energy) iii Construction of building (Induced Energy) and iv Operation of the building (‘Operational’ Energy).

Majority of GHG emissions take place during the operational phase of buildings when energy is used for

HVAC, lighting, appliances and other applications.

Environmental Effect of a Building


Performance

• Elements (Technology & Materials) –Efficiency, Effectiveness & Productivity

• Resources – Economic, Eco- behaviour, Design

• Environmental – Adaptability, Functionality, Environmental Quality

Attributes


Construction Process

Majority of the Energy Consumption and Environmental Impacts (CO emission Resource use & Replacement, wear and tear Water Pollutionetc.) takes place during the Life – Cycle stage

Source: Osman Attmann


Why Retrofitting Existing Buildings?

A city of only new green buildings does not make a sustainable city - we also need to address green retrofitting of existing buildings along with other wider issues such as waste management, water conservation, efficient transportation and renewable energy usage to reduce impact on the environment.


Concept of Developing Sustainable Cities


Green Retrofit• Green Retrofits - are any kind of upgrade(s)

at an existing building that is wholly or partly occupied -• To improve energy and environmental

performance, • To improve the comfort, • To reduce water use, • To improve the quality of space in terms

of natural light, air quality, and noise etc.

All done that is financially viable with payback guarantees.

(Source: USGBC)


Retrofitting Existing Buildings

Buildings which were constructed about 50-60 years before and that have a

remaining service life of minimum 20-25 years - presents a good retrofitting

potential for energy saving in buildings through active & passive strategies.

Refurbishment , Retrofitting & Renovation

Refurbishment – returning the building or its systems to their original condition, addressing the forces of physical obsolescence.

Renovation - attacks the effects of obsolescence. Retrofitting - the replacement & up gradation of old systems and

addition of new technologies for the purpose of improved efficiency to address technological or environmental obsolescence.[Richard Hyde, 2013]

Application of both Technical & Non-technical Strategies can be applied to existing buildings through the process

of retrofitting using Bioclimatic & Eco- design Principles.

Olgyay , 1963


Approaches to Green Retrofitting -Architect’s Perspectives

Active & Passive Strategies …..?Without Touching the Building…?Intelligent Features …………….?


Availability of diversified retrofit options through three different modes

of influences on buildings environmental loads and internal loads.

Tangible externalitiesBuilding designEnvelope architectureEnvelope materialsBuilding sectional fo rmBuilding plan form

Tangible and intangible internalities

Equipment

Occupancy profile3

Level / Mode In tangible externalities

Micro climate an d Climate

Level / Mode In tangible externalities

Micro climate an d Climate

Architectural dimensions of externalitiesHeavy or light massSkin or Core DependentOpen or Compact Plan

Thermal Load Profile

• Environmental loads

• Internal loads

2

1


• Sustainable & Green Retrofitting

• Bioclimatic Retrofitting (Naturally ventilated, solar heated/ cooled, well insulated, optimum daylight, Use fresh air etc.)

• Ecological Retrofitting (Extension to the Bioclimatic Approach)

• Energy Retrofit (Active Retrofit - Lighting, HVAC etc.)

• Envelope Retrofit (Glazing, Walls, Roofs, Floors etc.)

• Insulation Retrofit (Walls, Floors & Roof insulation)

Focus Areas of Research on Retrofits - Architects


• Solar Retrofit (Grid connected PV system, BIPV [façades & roofs], solar heating & cooling etc.)

• Roof & Wall Retrofit (Green roof & walls)

• Water Retrofit (Rooftop Rainwater Harvesting, Ground Water Recharge & Drip Irrigation, surface water collection, water bodies etc.)

• Intelligent Building Envelopes

Focus Areas of Research on Retrofits


Other Retrofitting Actions / Research:

• Carbon Reduction & Occupant Comfort.• Sewage Treatment Plants (STPs). • Shading of Envelope (Roofs, Walls & Glazing)

by fabrics etc.• Recycled water for flushing & irrigation etc.• Low embodied energy materials, low

emissions materials, Reusable & Recyclable materials.

Other Possible Actions for Green Retrofit



Examples – Evaporative Cooling

• Earth Air Tunnel System with Evaporative Cooling -Ambient Air at 44 °C is brought down to about 32 °C.

• Air coming from EAT pass through the Evaporative Cooling Unit to bring down the temperature to about 21 °C.

Air Cooling by Wind Towers with Misting Nozzles – System based on 100% fresh air supply to the occupants.


Geothermal Boreholes with Evaporative Cooling –

System is based on fresh air.• Water from the Geothermal holes is pumped

in the special designed AHU Coils to reject the heat.

• Ambient Air at 44 °C is brought down to about 35 °C without adding moisture to it.

• Temperature of 27-29 °C can be maintained inside.


In India by 2025, one person in three will live in conditions of absolute water scarcity.About 65% of households across 7 major cities face water deficiency.


Domestic waste Water

Use of Treated Grey Water

Gardening and Irrigation

Toilet flushing WashingOther applications

Car washingFire fighting etc


Recycling GW to gardening

Overflow to sewer Toilet and Kitchen

to Sewer

GW from bathroom and laundry

Schematic of Overall Treatment System


Advantages of Grey Water Recycling

• Lower the fresh water use Upto 40 %• Reduces strain on treatment plants• Reduces environmental degradation, and other

health hazards• Ground water recharge• Appropriately applied, greywater may contain

nutrients (e.g. phosphorus and nitrogen from detergents), benefiting plant growth.


Phytorid Treatment of Waste Water

CSIR- NEERI


Approaches to Green Buildings /Retrofit

a. Designing for Biodiversity – To minimize any impact upon the local ecology and to deliver wider ecological benefits / enhancements. This can be achieved through-i) Series of water bodies to cool down the

air temperature;ii) Reduce storm water, run –off, shading, etc.

b. Use of Pervious Concrete – Pervious / Permeable concrete instead of conventional concrete to enhance the replenishment of ground water.

Interventions without touching the building


Approaches to Green Retrofit

c. Vegetative surface on Roof – To slow down the rainwater runoff, helping to keep

the building cool, ameliorating “Urban Heat Island” effect and contributing to the

filtration of pollutants from the atmosphere.

d. Green Walls – Vertical vegetated surfaces on solid walls, providing visual amenity for the public and helping rainfall attenuation, dust filtration, and reduce urban heat island effect.




e. Deciduous Trees – Plant trees on South & Western side to maximize their benefits; helping to shade the lower part of the building during hottest months of the summer and when trees drop leaves, allow sunlight to warm building during the winter.No. of trees cut down to be replaced by new trees planted in the ratio of 1:3 + 25% extra.




f. Rainwater Harvesting – To harvest rainwater for irrigation purposes to reduce municipal storm water runoff. - To minimize the wastage of water drip irrigation systems ( micro – irrigation) to deliver water directly to plants.




g. Indoor Plants for Combating “Sick Building Syndrome” – To keep indoor plants e.g. Bamboo

Palm; to improve air quality and remove Formaldehyde, Benzene and Carbon Monoxide

from the air e.g. Areca Palm – Plant that removes CO•& coverts into oxygen. We need four shoulder – high plants per person, and need to wipe the leaves daily.Mother –in – Law’s Tongue – Plant that coverts CO•into oxygen at night. One requires about 6-8 such waist high plants per person in a room ( Building with 24 hrs use).Money Plant – Excellent plant for removing Formaldehyde and other VOC’s in the air.-




h. Composting – To recycle organic waste from fruit peels, grass clipping, leaves, etc. and mix into garden soil –to improve soil moisture retention; reduce municipal waste; to boost

plants’ immune system; and to reduce the need for chemical fertilizers.



• Reduce hard paving on site & increase Pervious surfaces.

• Passive solar control / Sun shading devices (adjustable)

• Low embodied energy materials, low emissions materials, Reusable & Recyclable materials.

• Construction & Demolition waste management.

Other Retrofitting Actions


Opaque Wall Assembly U- factor and Insulation R-valueRequirements as per ECBC 2007 & NBC 2013

None of the Wall Assemblies fulfill the Criteria Source: ECBC,2008 & NBC - 2014


Burnt brick masonry (229 x 114 x 76mm)

345 mm burnt brickU – Value: 1.720 W/m²K

229 mm burnt brickU - Value :2.283 W/m²K

15mm ce ment plaster + 345 mm burnt brick + 15mm cement plaster

U – Value: 1.610 W/m²K

76mm

76mm

15mm thick cement plaster


Cement Concrete Block Masonry (300 x 200 x 150 mm)

15mm cement plaster + 200 mm C.C. Block + 15mm cement plasterU – Value – 2.348 W/m²K







Improving Thermal Performance of Existing Buildings

• Building Envelope Thermal Performance –

Improvements in Overall Thermal Transmittance of Opaque Wall Assemblies, Roofs , Fenestration - Glazing, Shading, Screens and Surface Finishes.

Retrofitting offers a great possibility to enhance the thermal comfort , indoor air quality and natural lighting

/ daylighting etc.

A key strategy for achieving energy savings.

The goal is to reduce the heatgain through the envelope


Building Envelope Improvements –Walls, Roofs , Fenestration -Glazing, Shading, Screens and

Surface Finishes (Overall Thermal Transmittance (U – value)

Enhancement of Thermal Performance - Roofs:

• Applying Over Deck Insulation • Inverted earthen pots• White glazed ceramic tiles or

Vermiculite tiles • Highly Reflective coatings • Green Roofs etc.

Enhancement of Thermal Performance - Walls :

• Applying Thermal Insulation

• Providing Air Cavities in walls• Green walls by Veg. / tiles• Double skin facades• Applying Coatings & Light

colour paints

Glazing : S+D+T, Coatings / Films, WWR

Retrofitting Interventions vary for each type of Wall & Roof & Glazing.


• Eq. used for calculating the overall U- factor of typical wall assembly construction:

U = 1/ (1/hi + • ni=1 Li / K i + 1/ ho)…….. (i)

Where, ho (19.86 W/(m2 K) and hi (9.36 W/(m2 K) are the outside and inside film heat transfer coefficients; Li and Ki are thicknesses and thermal conductivities of material layers . SP- 41 (S&T) -1987 & ASHRAE - 2009

Development of a MATLAB Program


To evaluate the U-values of different materials and thicknesses of retrofit insulation (using equations)

Applying Insulation on Wall Surfaces

• The effect of insulation is to reduce heat gain / loss. Insulation / materials with lower conductivity are preferred, as they are better insulators and reduce the external heat gains from the envelope.

• Insulation must be placed on the hotter side of the surface.

• In hot areas, insulation should be placed on the external side and In Cold Climates, Insulation on Inside.


Improved Building Envelope - WallA. Brick Masonry WallB. Plaster C. In sulationD. P aint / Gypsum Panels

INSIDE

Improving R- values of the wallReduces energy consumption for space heating in all climates


Sand Lime Brick Masonry (229 x 114 x 76 mm )

Sand lime brick masonry 229 mm

Sand lime brick

15 mm CP 1:6

15 mm CP 1:6 - inside

Steel frame 63 mm EPS Insulation fixed to steel frame

5 mm CP 1:110 mm C. plaster 1:7 with w. resist. putty & white reflective paint

Chicken / WWM fixed to insulation

Existing

Retrofit

(Existing U- value: 2.2063, Retrofit : 63 mm EPS, U-value : 0.44 )

Inside

Air Cavity of 20 mm reduces desired thickness by about 4%


Fire Resistance

• Although Retrofit by Insulation is useful in improving energy efficiency, Fire safety of the structures is equally important.

• Retrofitting Roofs by Insulation is preferred as it requires minimum amount of interventions ; however, wall insulation on the hotter side of the walls (outside) in all types of climates except cold, will require major renovation.

• But both the roof & wall insulation contributes immensely in improving energy efficiency


Roof Assembly U- factor and Insulation R-valueRequirements as per ECBC 2007 & NBC 2014

None of the Roofing Assemblies fulfill the Criteria Source: ECBC,2008 & NBC - 2014


Options for Energy EfficiencyConventional Option ( without Retrofitting)•Roof – 35mm thick Brick Tiles + 75mm Mud Phuska + 100mm RCC + 15mm CP•Walls – 229mm burnt clay bricks•Air changes per hour = 5•WWR to 45 % & Double glazing•Sun shading projection of 500 mm

Option -1 : (Retrofitted Model) • Reduced WWR to 15 %• Double glazing• Increased Sun shading projection

size up to 900 mm• Increased ceiling height to 3.9 m • Roof insulated with 80 mm thick

PUF • Cavity walls (229 mm internal wall

+ 50 mm air gap + 115 mm external wall)

Energy Simulation Modelling – Design Builder Software & eQUEST,


Options for Energy Efficiency Option-6•WWR of 45 %•Double glazing & Outer Glazing With Film in the vision panel •Sun shading projection size of 500 mm•Roof insulated with 100 mm thick PUF + 35 mm thick vermiculite tiles & white reflective paint •Walls – 400mm CC blocks•Windows open from 18:00 to 9:00 hrs. (ac/h = 5) along with exhaust fan

Option-12•Roof – 50mm thick Brick Tiles + 100 mm thick PUF + 120mm RCC + 15mm CP •Walls – 229 mm thick Sand-lime bricks


• There is vast scope for improving the energy & water efficiency, indoor environmental quality and thermal comfort by both active as well passive interventions and also by improving the microclimate of the immediate environments around the existing buildings.

• Retrofitting by Fire Resistant Insulation may play an important role in Retrofitting in India.

• CSIR – CBRI has already developed a Fire Resistant Insulating Material.


Concluding Remarks…..

• There is a need to update the Climatic data files of existing Indian cities after five years and add more number of cities so that realistic results can be obtained while doing simulated modeling.

• It has been observed that there is a deviation of about 10% in the result outputs when compared with real – time data.

• Hence, the existing climatic data files of the softwares can not be relied upon to get the accurate results but will give approx. picture.

Concluding Remarks…..


• There is a need to develop a Standard for the Design of High-Performance Green Buildings and Retrofitting Existing Buildings in India in line with ASHRAE, the International Code Council (ICC), American Institute of Architects (AIA), Illuminating Engineering Society of North America (IES) and the U.S. Green Building Council (USGBC) ASHRAE Standard 189.1.

• BIS, CSIR – CBRI, IITs & other Institutions may join hands.


For Details:Director, CSIR- CBRI, Roorkee.www.cbri.res.in, [email protected]

Documents

Sequence of the Presentation Architect’s Perspectives in ... · • Sustainable & Green Retrofitting • Bioclimatic Retrofitting (Naturally ventilated, solar heated/ cooled, well