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