Green Retrofitting of Existing Buildings: CSIR- Central Building Research Institute Initiatives

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1 National Conference Retrofitting of Renewable Energy and Energy Efficiency Systems for Sustainable Habitat Green Retrofitting of Existing Buildings: CSIR- Central Building Research Institute Initiatives December 18, 2014 Ashok Kumar Senior Principal Scientist & Head, Architecture & Planning

2 Outline of the Presentation Challenges & Issues Existing Building Stock - Impacts Green Buildings & Green Retrofitting Assessment of the Parameters Initiatives by CSIR- CBRI Concluding Remarks

3 Challenges Climate Change Energy Shortage Water Shortage Urbanization Some Solutions to these Challenges Green Buildings, Retrofitting Existing Buildings & Sustainable Cities

4 Challenges Climate Change (Green House Gas Emissions) Need to reduce greenhouse gas emissions to combat global warming 6-7% of the World CO 2 emissions from Cement production One ton of Cement produces ~0.9 ton of CO 2 Cement production is highly energy intensive process. Conservation of Natural Resources 3 billion tons of limestone 13 billion tons of aggregates Construction the largest Consumer of Resources Research Focus World Over

5 Construction Process Source: Osman Attmann Majority of the Energy Consumption and Environmental Impacts (CO₂ emission, Resource use & Replacement, wear and tear, Water Pollution etc.) takes place during the Life Cycle stage

6 Green House Gas Emissions The main source of GHG emissions from buildings is energy consumption. Energy is consumed during: (i) Manufacturing of building materials ( Embedded or Embodied Energy ) (ii) Transporting the materials from production plants to building sites ( Grey Energy) (iii) Construction of building (Induced Energy) (iv) Operation of the building ( Operational Energy).

7 Existing Building Stock India has about Billion sqm. 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). Major part of this consumption is directly related to buildings use & Approx. 80% of GHG emissions take place during the Operational Phase of Buildings, when energy is used for HVAC, lighting, appliances and other applications.

8 In terms of Sustainability, Retrofitting Existing Buildings is one of the Most Effective Strategies Retrofitting Existing Buildings into Green can help address National issues - Energy & Water Efficiency, Conserving the Natural Resources, Handling of all kinds of Wastes etc.

9 Relationship between the Green Categories Conceptual Framework for Measuring the Greenness of Architecture Ecological Sustainable GREEN Performance

10 Sustainability, Ecology & Performance Requires Measuring Green No. of Attributes Elements (Technology & Materials) - E Resources - R Environmental Env For example: Building can be completely or barely sustainable or un-sustainable depending upon the number of attributes it possesses within each of the subcategories EREnv.

11 Sustainable Measuring Green Attributes Elements (Technology & Materials) Durable, Economical, Recyclable, Low -Maintenance Resources Onsite conditions, Cost effectiveness, Accessibility, Natural Forces Environmental Healthy, Habitable, Social, Safety & security

12 Performance Attributes Elements (Technology & Materials) Efficiency, Effectiveness & Productivity Resources Economic, Eco- behaviour, Design Environmental Adaptability, Functionality, Env. Quality

13 Six Goals for an Overall Sustainability Assessment Optimization of site / existing structure potential; Optimization of energy use; Protection and conservation of water resources; Use of environmental friendly materials & products; Enhance IEQ; and Optimized O & M practices and create built environments that are livable, comfortable, safe, and productive.

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15 Green Rating for Integrated Habitat Assessment (GRIHA) GRIHA - Green building design evaluation system, is suitable for all kinds of buildings (except factory buildings) in different climatic zones of the country & NOT applicable for existing buildings. Categorization Site Selection and Site Planning (15%). Energy Efficiency and Renewable Energy (35%). Water Efficiency (15%). Materials and Resources (14%). Health and Well Being (15%). Solid Waste Management (6%). Innovation (beyond 100). Project Totals: 104 Possible Points (GRIHA, 2012 )

16 Leadership in Energy and Environmental Design (LEED ) - The most dominant system adapted worldwide. Scope of buildings LEED Core & Shell, LEED New Construction, LEED Schools, LEED Retail, LEED Healthcare, LEED Commercial Interiors, LEED Homes, LEED Existing Buildings and LEED Neighborhood Development. LEED India has been modified by Indian Green Building Council (IGBC) LEED 2009, includes: (New Construction and Major Renovations. SS- Sustainable Sites: (26 Possible Points) WE- Water Efficiency: (10 Possible Points) EA- Energy & Atmosphere: (35 Possible Points) MR- Materials & Resources: (14 Possible Points) EQ- Indoor Environmental Quality: (15 Possible Points) ID- Innovation & Design Process: (6 Possible Points) RP- Regional Priority: (4 Possible Points) Project Totals: 110 Possible Points (LEED, USGBC 2011)

17 Building Research Establishment Environmental Assessment Method (BREEAM) BREEAM is the first commercially available EA tool for buildings & has been used by many other rating systems as their development basis. Scope of buildings BREEAM is used for the certification of projects anywhere in the world. UK, Spain, Sweden and Norway, etc. Categorization BREEAM Europe Commercial covers Europe offices, retail and industrial buildings. Each section has its own weighting and categories are: MAN- Management: (10 possible points). HEA- Health and Wellbeing: (14 possible points). ENE- Energy: (21 possible points). TRA- Transport: (10 possible points). WAT- Water: (6 possible points). MAT- Material: (12 possible point) WST- Waste: (7 possible points). LE- Land Use and Ecology: (10 possible point) POL- Pollution: (12 possible points). Innovation: (10 possible points). Project Totals: 112 Possible Points (BREEAM Europe Commercial 2009)

18 Green Buildings ASHRAE Standard 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.

19 Concept of Developing Sustainable Cities

20 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.

21 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)

22 Retrofitting Existing Buildings Buildings which were constructed about years before and that have a remaining service life of minimum years - presents a good retrofitting potential for energy saving in buildings through active & passive strategies.

23 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 & Nontechnical Strategies can be applied to existing buildings through the process of retrofitting using Bioclimatic & Eco- design Principles. Olgyay, 1963

24 Initiatives by CSIR- CBRI Green Buildings, Green Retrofitting & Sustainability

25 CSIR CBRI Research Initiatives Envelope Retrofit -(Glazing, Walls, Roofs, etc.) Insulation Retrofit (Walls, & Roof ) Experimental Models Experimental data & Simulation Results validated Solar Retrofit - (BIPV roofs, etc.) CBRI Main Building Energy Retrofit - (Active Retrofit - Lighting, HVAC etc.) Simulation of CBRI Main Building Water Retrofit Strategies (Rooftop Rainwater Harvesting, Ground Water Recharge, Surface Water Collection, Water Bodies etc.) Evaporative Cooling - CBRI Library Block

26 Research on Sustainable & Green Retrofitting Bioclimatic Retrofitting (Naturally ventilated, solar heated/ cooled, well insulated, optimum daylight, Use fresh air etc.) Roof & Wall Retrofit (Green roof & walls) Retrofitting for reducing Embodied Energy

27 Bioclimatic Design In 1963, the Bioclimatic term was used for the first time by Victor Olgyay. Bioclimatology relates to the study of climate (climatology) to the human beings that relates bioclimatic data to thermal comfort limits, to identify design strategies (OLGYAY, 1973). Bioclimatic design is an approach that takes advantage of the climate through the right application of design elements and building technology to control the heat transfer process.

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29 Green Retrofit Strategies to achieve Energy Efficiency Active (Fans, HVAC, Solar Renewable etc.) Passive (Solar & Thermal Control and Passive Cooling etc.) Energy Efficiency Heat Protection Natural Resources Optimization Heat Dissipation Microclimate Solar Control Renewable Energy Usage Day lighting Thermal Mass Insulation Passive Cooling Landscaping WWR Solar Panels Mass Effect Fixed / Movable Insulation Natural Ventilation Natural Vegetation Glazing Intelligent Building Envelope(IBE) Evaporative Cooling Water body Shading

30 Experimental Models at CSIR- CBRI Campus

31 Retrofitting Strategies for Energy Conservation Insulation Wall & Roof Green Roof & Walls Shading Landscaping - Improving the Microclimate Evaporative cooling

32 Approaches to Green Buildings /Retrofit Interventions without touching the building a. Designing for Biodiversity To minimize any impact upon the local ecology and to deliver wider ecological benefits / enhancements. This can be achieved throughi) 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.

33 Approaches to Green Retrofit Interventions with touching the building 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.

34 Approaches to Green Retrofit Interventions without touching the building e. 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.

35 Window to- Wall Ratio (WWR) WWR

36 6 mm Clear Glass Single 5 mm Dew Drop 6 mm Dew Drop 8 mm Dew Drop 5 mm Aquamarine 6 mm Aquamarine 5 mm Clear Cosmos 6 mm Clear Cosmos 8 mm Clear Cosmos 4 mm Reflectasol 5 mm Reflectasol 6 mm Reflectasol 6 mm Iris SKN+ 12 mm Air + 6 mm clear 8 mm Iris SKN+ 12 mm Air + 8 mm clear 6 mm Xtreme + 12 mm Air + 6 mm clear 6 mm Icy menthol + 12 mm Air + 6 mm clear 6 mm Icy menthol + 12 mm Argon + 6 mm clear 6 mm cosmos + 12 mm Air + 6 mm clear 6 mm Low-E + 12 mm Air + 6 mm clear 6 mm Low-E + 12 mm Argon + 6 mm clear 6 mm Dew Drop + 12 mm Air + 6 mm clear 6 mm Dew Drop + 12 mm Argon + 6 mm clear 6 mm Reflectasol + 12 mm Air + 6 mm clear Annual Savings (INR) Glazing WWR = 45% WWR = 50% WWR = 60% Single Double

37 6 mm Clear Glass Single 5 mm Dew Drop 6 mm Dew Drop 8 mm Dew Drop 5 mm Aquamarine 6 mm Aquamarine 5 mm Clear Cosmos 6 mm Clear Cosmos 8 mm Clear Cosmos 4 mm Reflectasol 5 mm Reflectasol 6 mm Reflectasol 6 mm Iris SKN+ 12 mm Air + 6 mm clear 8 mm Iris SKN+ 12 mm Air + 8 mm clear 6 mm Xtreme + 12 mm Air + 6 mm clear 6 mm Icy menthol + 12 mm Air + 6 mm clear 6 mm Icy menthol + 12 mm Argon + 6 mm clear 6 mm cosmos + 12 mm Air + 6 mm clear 6 mm Low-E + 12 mm Air + 6 mm clear 6 mm Low-E + 12 mm Argon + 6 mm clear 6 mm Dew Drop + 12 mm Air + 6 mm clear 6 mm Dew Drop + 12 mm Argon + 6 mm clear 6 mm Reflectasol + 12 mm Air + 6 mm clear Annual Savings (INR) Composite Hot & Dry Warm & Humid Moderate Single Double

38 Shading Devices

39 Retrofit Models with Landscape Elements Existing Eucalyptus Trees Water body on the south east side for natural cooling effect. Fountain on the north west side for natural cooling effect. Ashoka Trees on the south side for shading in summer and solar access in winters

40 Landscaping - Trees Without Trees 3 Trees in SE 5 Trees in SE

41 Green Roof Retrofit System for Buildings built with Prefab Brick Panel Roofing Technology Green roof retrofits to improve the micro-climate can be used efficiently in existing buildings where the additional load carrying capacity of buildings about kg/m² is permissible.

42 Green Roofs Technical and economic feasibility of green roofs on prefab Brick Panel Roofing system investigated for composite climate of India. In Warm Summers, green roofs are suitable for reducing the energy demand for the space cooling, with annual reduction of the primary energy requirements between 5% - 10%, without worsening the winter energy performance. Cost of Proposed Green Roof Retrofit is Rs.100 per sqft..

43 Parametric Study for making Existing Buildings Green Building Envelope Thermal Performance Improvements in Overall Thermal Transmittance of Opaque Wall Assemblies, Roofs, Fenestration - Glazing, Shading, Screens and Surface Finishes. The goal is to reduce the heat gain through the envelope 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.

44 Building Envelope Improvements Walls, Roofs, Fenestration -Glazing, Shading, Screens and Surface Finishes (Overall Thermal Transmittance (U value) 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 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. Glazing : S+D+T, Coatings / Films, WWR Retrofitting Interventions vary for each type of Wall & Roof & Glazing.

45 Opaque Wall Assembly U- factor and Insulation R-value Requirements as per ECBC 2007 & NBC 2013 None of the Wall Assemblies fulfill the Criteria Source: ECBC,2008 & NBC

46 Burnt Brick Masonry (229 x 114 x 76mm) 15mm thick cement plaster 76m m 76 mm 229 mm burnt brick U - Value :2.283 W/m²K 345 mm burnt brick U Value: W/m²K 15mm cement plaster mm burnt brick + 15mm cement plaster U Value: W/m²K

47 Cement Concrete Block Masonry (300 x 200 x 150 mm) 15mm thick cement plaster 15mm thick cement plaster 15mm thick cement plaster 15mm cement plaster mm C.C. Block + 15mm cement plaster U Value W/m²K 15mm cement plaster mm C.C. Block + 15mm cement plaster U Value W/m²K 15mm cement plaster mm C.C. Block + 15mm cement plaster U Value W/m²K

48 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

49 Criteria for Thermal Performance Rating Computing (K) and thermal transmittance (Ufactor) are prerequisites for the assessment of thermal performance of building sections. Thermal Resistance (R) for a structure having plane parallel faces is equal to thickness (L) of the structure divided by thermal conductivity (K). Thermal conductance, C = K / L (i), R = 1 / C = L / K.... (ii) For a composite material comprising several layers of conductivities K 1, K 2 etc., and of thicknesses L 1, L 2 etc., the Thermal Resistance is : R T = R 1 + R 2 + R 3 + R 4 + R 5 +. (iii) Where, R T is the total resistance of the materials

50 Development of a MATLAB Program Eq. used for calculating the overall U- factor of typical wall assembly construction: U = 1/ (1/h i + n i=1 L i / K i + 1/ h o ).. (i) Where, h o (19.86 W/(m 2 K) and h i (9.36 W/(m 2 K) are the outside and inside film heat transfer coefficients; L i and K i are thicknesses and thermal conductivities of material layers. SP- 41 (S&T) & ASHRAE

51 Burnt Clay Brick Masonry (229 x 114 x 76 mm )

52 Sand Lime Brick Masonry (229 x 114 x 76 mm ) (Existing U- value: , Retrofit : 63 mm EPS, U-value : 0.44 ) Air Cavity of 20 mm reduces desired thickness by about 4% Inside 15 mm CP 1:6 - inside Sand lime brick masonry 229 mm 15 mm CP 1:6 Steel frame 63 mm EPS Insulation fixed to steel frame Chicken / WWM fixed to insulation 5 mm CP 1:1 10 mm C. plaster 1:7 with w. resist. putty & white reflective paint Sand lime brick E x i s t i n g R e t r o f i t

53 U-values and thicknesses of retrofit insulation MATLAB Program Air Cavity of 20 mm reduces desired thickness by about 4%

54 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.

55 Roof Assembly U- factor and Insulation R-value Requirements as per ECBC 2007 & NBC 2014 None of the Roofing Assemblies fulfill the Criteria Source: ECBC,2008 & NBC

56 240 Options for Energy Efficiency Changing the Variables Conventional Option ( without Retrofitting) Roof 35mm thick Brick Tiles + 75mm Mud Phuska + 100mm RCC + 15mm CP Walls 229mm burnt clay bricks Air changes per hour = 3 WWR to 45 % & Single glazing Sun shading projection of 500 mm Option-2 (Retrofitted Model ) Reduced WWR to 15 % Double glazing Increased Sun shading projection size up to 900 mm Green roof Cavity walls (229 mm internal wall + 50 mm air gap mm external wall. Option -1 : (Retrofitted Model) Reduced WWR to 15 % Double glazing Increased Sun shading projection size up to 900 mm Ceiling height 3.9 m Roof insulated with 80 mm thick PUF Cavity walls (229 mm internal wall + 50 mm air gap external wall)

57 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 mm thick PUF + 120mm RCC + 15mm CP Walls 229 mm thick Sandlime bricks

58 SPV Modules mounted on Roof Tops in the CSIR-CBRI Building

59 Table : Boundary conditions of the reference building for simulation Description Value Building size Two and three storeyed with entrance on ground floor Front orientation North West Operating schedule 8:45 to 17:30 ( 5days / week) Walls Burnt clay brick masonry 345 mm thickness Roof Reinforced cement concrete 100 & 120mm thick Floor Reinforced cement concrete 120mm thick Windows type Single glazed, clear glass, 3 mm thickness with & without horizontal or vertical blinds Window sizes Width varies from 1500mm to 2700mm & height varies from 1350 mm to 1650mm Window shading Blinds Local shading type Both horizontal & vertical louvers Occupancy 1 person per 9 m 2 to 20m 2 Lighting type Compact fluorescent Lighting power density 10 w/m 2 Cooling type Window & split air - conditioners Cooling power density 40 to 60 w/m 2 Ventilation power 5 w/m 2 density

60 Diesel consumption and cost of units generated through DG sets Description Number of Units per Hour Total Units generated by 300 DG sets Diesel Consumption 100 liters / (2 x 50 liters / hour) hour (3 units/liter) Cost 2010 (Indian Rupee) Cost 2014 (Indian Rupee) Cost of Diesel Rs 39 per liter Rs. 51 per liter Cost of unit generated by Rs. 13 per Rs per DG sets unit unit Net cost of unit generated Approx. Rs per considering operation & Rs per unit maintenance costs unit

61 Table : Total installed capacity based on average age Avg. AC Age (<5 Years) Nos. Total Installed capacity (In TR) x x 2 = 26 Avg. AC Age (5-10 Years) (Old technology) Avg. AC Age (10-20 Years) (Old Technology) Nos. Total Nos. Total Installed Installed capacity (In capacity TR) (In TR) x 1.5 = x (50%) 12 x 2 = 75

62 Table : Cost Benefit Analysis of energy efficient Star labeled air- conditioners Description Remarks Total installed capacity of old AC Units 103 TR Annual energy consumption by old air conditioners 211,356 kwh considering 8 hrs./day and 150 days operation in a year (103 x 1.71 x 8 x 150 kwh) Annual energy consumption by new energy efficient air 129,780 kwh conditioners operating for 6 hrs./day for 150 days/annum (103 x 1.40 x 6 x 150) kwh Net energy saving units Annual cost saving (81576 x 3.93/Unit) Rs. 3,20,593/- Average cost of energy efficient Star labeled AC units Rs. 23,000/- (1.5 TR) Total ACs which can be replaced 103 nos. Total Investment required Rs. 23, 69,000/-

63 Table : Cost Benefit Analysis of improved Luminaires Description Remarks Total number of tube lights installed in the reference 410 building Total Power consumption ( 410 x 55 watts) kwh Total power consumption with T5 lamps ( 410 x 28 watts) kwh Net power saving with T5 lamps kwh Annual energy saving (Assuming 8 hours operation per 23,025 kwh day for 260 days) (11.07 x 8 x 260 kwh) Annual Cost 3.93 per unit Rs. 90,488/- Cost of T5 lamp with conversion kit Rs. 800/- Total lamps which can be replaced 410 Total Investment Required Rs. 3,28,000/-

64 Table : Cost benefit analysis of energy efficient fans Description Remarks Total number of old ceiling fans installed in the reference 160 building Total power consumption (160 x 96 Watts) kw Total power consumption with energy efficient ceiling fans 8.00 kwh (160 x 50 watts ) Net power saving 7.36 kwh Annual energy saving assuming 8 hours operation per day 11,776 kwh for only 200 working days excluding the cold season (7.36 x 8 x 200 ) kwh Annual cost 3.93 per unit Rs. 46,279/- Cost of one energy efficient ceiling fan Rs. 1500/- Total fans which can be replaced 160 Total Investment Required Rs. 2,40,000/-

65 Table : Cost Benefit Analysis of Solar PV Plant Description Total (Rs.) 100 KWp Solar PV modules along with Solar Power Control Unit, Battery Back-up, Solar Array Mounting Structure & fittings including 5% (A) 2,62,00, Installation & Commissioning of Solar PV Plant (B) 8,00, Sub Total (A+B) 2,70,00, Service Tax on 10.3% (C) 27,81, Total project cost for installation and commissioning (D) = (A+B+C) 2,97,81, Availability of Subsidy by MNRE, 90% 2,68,02, Total Investment for CBRI, Roorkee 29,78, Average output achieved during May 7, 2013 till date 70% with maximum reaching 79 % as against 90% (due to cloudy weather during the period). Power production with 70% output 70 KWh 9 hours per day (8:00 to 17:00 hours) = 9 x KWh Total production per annum with 75% efficiency Payback period (@ Rs. 19/- per unit generated by DG sets) 2,29,950 KWh 7 months

66 SPV modules mounted on roof tops in the reference building

67 SPV modules arranged in panels of five with a tilt of 25 degrees

68 Other Research Focus Low Carbon Cement Cement free Concrete Bio- Concrete Recycled Aggregates Sustainable & Ecological Materials - Utilization of Waste eg. Wood without Tree - Energy Efficient Materials - High Performance Materials &Technologies Low VOC materials for interior finishes And many more

69 Rice Husk Plastic Wood Replacement of natural wood in door & window frames, furniture and structural supports. Carpenter tool friendly. Meets requirements of structural wood as per NBC. Moisture and termite resistant.

70 Pine Needle Composite Boards Conform to IS : Fire resistant. Easy to laminate and paint. Pine needle available in Western Himalayas

71 Natural Fibre Composite Panels & Door Shutters

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75 TO SUM UP. There is vast scope for energy efficiency improvement in existing buildings. Studies have revealed, a savings potential of 40% lighting, cooling, ventilation, refrigeration etc.

76 For Further Information Contact: ,