Date post: | 07-Jan-2017 |
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ZER0 ENERGY BUILDING ENVELOPE COMPONENTS
Sanjay Neupane
(Objectives)• Concept of Zero Energy Building
• Façade components & Z.E.B
• Integration of components
(Zero Energy Building)
(Net ZEB Definition)
(Building Envelope)• Building shell, fabric or enclosure >>boundary between the conditioned
interior of a building and the outdoors.
(Building Envelope & Energy )• Glazing and façade systems >> large impacts on all aspects of building
performance.
= 75%
(Envelope Components)
• Provide thermal and acoustic comfort >> aesthetics.
• Thermal resistance (R-value) of the wall is crucial >> building energy
consumption
• Wood-based walls, metal-based walls and masonry-based walls
o Passive solar walls
o Walls with latent heat storage
o T-Mass Walls:
o Riverdale NetZero Deep Wall System
o Green Walls
(Walls)
Passive Solar Walls
• Trap and transmit the solar energy
• Glazing is used >> greenhouse effect
(Walls)
Walls with latent heat storage
• Phase change material (PCM) is incorporated >> thermal storage capacity
• Porous material such as plasterboard has better PCM
• Reduces temperature by 4 ◦C and the heating demand during night
(Walls)
T-Mass Walls
• Styrofoam extruded polystyrene board insulation sandwiched in between.
(Walls)
Riverdale NetZero Deep Wall System
• Double-stud wall system >> cavity >> cellulose insulation
• DWS has very high insulation values
(Walls)
Green Walls
• Reduce heat transmittance >> direct shading and evapotranspiration.
(Walls)
Panel Type Mini planter Cage System Box
• Lightweight roofs
• Solar-reflective/cool roofs
• Green Roofs
• 100 mm thickness increase >>
resistance by 0.4 m2K/W
(Roofs)
• Photovoltaic Roofs
• Roof Vents
• Rubber Roofs
• EPDM (ethylene propylenediene Monomer)
• Highly recyclable nature
(Roofs)
• Windows with low U-value and high total solar energy transmittance (Г) are preferred.
• Heat loss and heat gain through windows occurs at 20–30 times the rate they occur through walls.
Aerogel glazing
• 90–99.8% air by volume.
• volume porosity of greater than 50%.
• 2mm >> 30% energy saving
Vacuum glazing
• Triple vacuum glazing >>thermal
transmittance of less than 0.2 W/m2 K
(Windows & Doors)
Switchable reflective glazing /Suspended particle devices (SPD) film
• Electrically switchable glazing , changes light transmission properties when voltage is applied.
• Control the amount of light and heat passing through
• Applying a low DC voltage (electrochromics (EC)) or by using hydrogen (gasochromics)
(Windows & Doors)
High Thermal Performance Glazing
Dynamic Glazing
• Based on electrochromic technology
• Switches between clear and tinted states
Building integrated photovoltaic glazing
• 10 to 12 Watts per ft²
(Windows & Doors)
• Edge components (frame and spacer)
Thermal Break Frames
Consisting of an insulated material is needed to stop heat transmission
• Reduce heat loss
• Prevent frost/condensation
• Positive thermal break within the frame profile
Kerf Frames
(Frames)
Types of Insulation
• Mineral Wool
• Expanded polystyrene (EPS)
• Extruded polystyrene (XPS)
• Cellulose
• Cork
• Vacuum insulation panels (VIP)
• Aerogels
• Vacuum insulation materials (VIM)
• Dynamic insulation materials (DIM)
• NanoCon
(Windows & Doors)
(Case Study 1 - NREL)• Location -Golden Colorado (24 miles west of Denver).
• 822 employees working capacity with 79% occupancy in gross square footage 220,000.
• Determined ZEB and LEED Platinum best practices and strategies
(Case Study 1 - NREL)Zero Energy Strategies
(Envelope Components)
PV System
Natural Ventilation
Thermal Mass
UFAD
Labyrinth
Transpired Collectors
Radiant Cooling
Radiant Heating
Day lighting
60’
Photovoltaic roofs
• 1.6 MW of on-site photovoltaic (PV)
(Roofs)
Passive Solar Walls - Transpired Solar Collector
• Metal sheet perfo-rated with small holes.
• Uses solar energy to heat and ventilate indoor spaces.
(Walls)
T-Mass Walls - Precast Exterior/Interior Insulated Panels
3” architectural Precast concrete l 2” rigid insulation l 6” concrete
(Walls)
Zinc
Pre-cast Concrete
Transpired Collector
High Thermal Performance Glazing - Triple-Glazed Windows with Individual Overhangs
• North and South >> triple glazed
• North windows larger than on south elevation
(Windows)
Dynamic Glazing
- E-W elevations feature thermo-chromic>> reduce heat loss and electro chromic glazing>> reduce heat gain
(Windows)
(Windows)Glare Control + View Window
Daylight Control + Daylight Window
Daylight Enhancement
(Below grade System)Labyrinth Thermal Storage-Air heated by the transpired solar collector heats the thermal mass >> preheats ventilation air. -The labyrinth can warm outside air by 5–10°F.
(Case Study 2 - BCA)• BCA - Building and Construction Authority
• Location 200 Braddell Road, Singapore
• Official purpose, as visitor centre ,as library and also as multipurpose area.
• Retrofitted Zero Energy Building (ZEB) located at BCA Academy >> threestorey addition and alteration
(Approach)Active Systems
Efficient Lighting•T5 Fluorescent lights•LED task lighting•State-of-the art lighting control systems
Efficient ACMV•Personalized Ventilation•Underfloor air distribution system•Single coil twin fans•Solar chimneys
Active Control• State-of-the-art building management system
Passive Systems
Efficient Envelope• Type of window glazing•Type of wall/facade
Minimize Solar Heat Gain• Roof garden & vertical greenery•Sunshades
Capitalize Day lighting•Mirror ducts•Light pipes•Light shelves
(Envelope Components)
PV System
Natural Ventilation
Shading Device/Solar cells
Thermal Performance glazing
Green Walls
Vent/Solar Chimney
Photovoltaic Roofs
• Elevated about 1 ft. off the metal roof
>>ensure ventilation and cool
• PV system of 190 kWp
Green Roof
• Solar radiations are absorbed by the greenery >>creates thermally comfortable environment
Roof Vents
• Solar Assisted Stack Ventilation
Light weight Roofs
(Roof)
Green Walls
• Unusual Aspects and Aesthetic Values
• Approx 50% of green wall and 43% glazing
(Walls)
• High Thermal Performance Glazing - Double Glazed Unit
• Sun Shades with PV
• Low-e glass
(Windows)
(Energy Conservation)
(Analysis)• Façade components are the major parts for energy conservation• Transfer of costs from HVAC capacity to architectural elements.
(Analysis)• Different from conventional buiding
(Analysis)• Impacts on all aspects of building performance.• Influence peak heating and cooling loads, and indirectly influence
lighting loads • Roof, walls, windows, doors, etc. >>considered for energy efficiency.• Simpler forms i.e., cavity insulated walls, cool paints, double glazing and
low-emissivity glass • Sophisticated façade systems – i.e., triple-glazing systems, double skin
façade systems, the use of photochromic glass and electrified glazing, etc.
• The financial requirements depend on the choice of façade system.
(Analysis)INNOVATION
• Inspired from Nature
• Inspired from technology
(Conclusion)• Z.E.B >> Future of Building Design
• Façade >> important role in energy conservation
• Simple traditional techniques could help for better thermal efficiency
• Façade components such as walls, fenestration, roof, foundation,
thermal insulation, thermal mass, external shading devices etc. make
up this important part of any building.
(References)• P. Torcellini, S. Pless and M. Deru, (2006), Zero Energy Buildings: A
Critical Look at the Definition, National Renewable Energy Laboratory (NREL)
• Karma Swayer, (2014), Windows and Building Envelope Research and Development: Road map for emerging Technologies
• Sunil Kumar Sharma, (2013), International Journal of Engineering Research and Applications (IJERA)
• P. Torcellini, (2012), the Design Build Process for the Research Support Facility
• US Department of Energy (2007), Annual Energy Review 2006
(References)INTERNET SOURCE• Solar Walls, How solar walls works,
http://solarwall.com/en/products/solarwall-air-heating/how-solarwall-works.php, viewed 15th February 2016
• Building and construction authority, www.hpbmagazine.org, viewed 10th February 2016
• High Performance Building Façade, http://www.climatetechwiki.org/technology/high-performance-facades, viewed 22 February 2016
• Building and construction authority, Singapore government, http://www.greenmark.sg/about_proj_zero.html, viewed 29th January 2016
Let’s find beauty in the Number
ZERO