Dr. Brent Stephens, Ph.D. Civil, Architectural and Environmental Engineering

Illinois Institute of Technology brent@iit.edu

Advancing energy, environmental, and sustainability research within the built environment www.built-envi.com Twitter: @built_envi

CAE 331/513 Building Science Fall 2016 Week 15: December 1, 2016 Standards and guidelines for energy efficiency

Schedule

•  Graduate students: Final reports due Thurs Dec 1st, 11:59 pm –  Move to Monday 8 am

•  All: HW 6 due Thurs Dec 1st in class –  Can turn in by Friday by 5 pm without any points off

•  Final exam (all students): December 8th, 2-4 pm

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Last time: Building energy simulation •  There are many software packages available (some are free)

•  EnergyPlus •  eQUEST •  IES-VE •  TRNSYS •  Many others

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http://apps1.eere.energy.gov/buildings/tools_directory/subjects.cfm/pagename=subjects/pagename_menu=whole_building_analysis/pagename_submenu=energy_simulation

Building energy simulation equations

•  For an example room like this, you would setup a system of equations where the temperature at each node (either a surface or within a material) is unknown –  12 material nodes + 1 indoor air node

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Room

F

C

L R

1

1

11

2

2

22

3

3

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A air node

internal surface node

external surface nodeelement-inner node

Con

vect

ion

Rad iati onmcpdTdt

= qat boundaries∑

At surface nodes: q∑ = 0

At nodes inside materials:

Unsteady conduction (storage) is based on density and heat capacity of material

Heat Xfer @ external surfaces: Radiation and convection

Unsteady energy balance for air node •  To get the impact on indoor air temperature (and close the system of

equations) –  Write an energy balance on the indoor air node –  Air impacted directly only by convection (bulk and surface)

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(Vroomρaircp,air )dTair,indt

= hiAi Ti,surf −Tair,in( )i=1

n

∑ + mcp Tout −Tair,in( )+QHVAC

F

C

L R

3

3

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A air node

EiQHVAC In plain English:

The change in indoor air temperature is equal to the sum of convection from each interior surface plus outdoor air delivery (by infiltration or dedicated outdoor air supply), plus the bulk convective heat transfer delivered by the HVAC system

Qinfiltration

6 McKinsey & Company, 2009 Unlocking energy efficiency in the US economy

Energy efficiency is actually inexpensive

$520 billion in investment à $1.2 trillion in savings through 2020

BUILDING DESIGN GUIDELINES AND STANDARDS

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Designing for efficiency

•  Whether designing a new building or retrofitting an old building…

•  There are a number of building codes and standards that help design for energy efficiency and sustainability

•  Codes generally provide minimum criteria –  Your building can’t be worse than this –  City codes, state codes, national codes, etc.

•  Standards often go above and beyond code –  Or can become cited in code

•  Green building standards –  Several green building standards exist with varying levels of building

energy efficiency criteria

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State energy codes: Commercial buildings

9 http://www.energycodes.gov/status-state-energy-code-adoption

Designing for efficiency: Codes, standards, and guidelines

•  ASHRAE Standards and Guidelines –  Standard 90.1: Energy standard for buildings except low-rise

residential buildings –  Standard 90.2: Energy efficient design of low-rise residential buildings –  Standard 189.1: Standard for the design of high-performance, green

buildings –  Advanced Energy Guidelines for 30% and 50% savings

•  IECC: International Energy Conservation Code –  From the International Code Council (ICC)

•  IRC: International Residential Code

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•  ASHRAE 90.1-2007, 2010, 2013, and now 2016 Energy Standard for Buildings Except Low-Rise Residential Buildings

•  Look for Addenda to the standard –  Corrections and changes –  http://www.ashrae.org/standards-research--technology/standards-addenda

ASHRAE Standards 90.1 and 90.2

•  ASHRAE/ANSI/IESNA 90.1 –  Energy Standard for Buildings Except Low-Rise Residential Buildings –  Will continue to be reference for commercial buildings –  First appeared in 1975 with major updates in 80,89,99,04,07,10,13,16

•  Major changes include a change in climatic categories and lighting power density

•  ASHRAE Standard 90.1 is the basis of energy efficiency for nearly all Building Codes and Green Building Ratings –  ICC codes, DOE/Federal Government Codes, State and City Codes, LEED,

Green Globes

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What is in ASHRAE Standard 90.1?

•  90.1 has energy performance requirements for: –  Building enclosure –  Lighting –  HVAC equipment –  Water heating –  Power delivery systems, and more

•  Purpose and scope

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ASHRAE 90.1: Table of contents

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ASHRAE 90.1: Climate zone specific

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Select your climate zone

ASHRAE 90.1: Building envelope

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Satisfy mandatory provisions: Sealant requirements •  Locations where joints must

have sealants applied

Air leakage •  Maximum air leakage of doors

and windows

Vestibule entrances •  Requirements for the use of

vestibules or revolving-doors at an entrance

Select your path for compliance

ASHRAE 90.1: Building envelope (IP)

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Prescriptive path: Requirements for U, R, and SHGC for enclosure elements

ASHRAE 90.1: Building envelope (IP)

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Prescriptive path: Requirements for U, R, and SHGC for enclosure elements

ASHRAE 90.1: HVAC

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Satisfy mandatory provisions: Must perform load calculations •  ASHRAE Standard 183 •  Radiant time series or

heat balance method

Other items: •  Thermostat controls •  Fan speed controls •  Minimum damper leakage •  Duct insulation •  Fan power limits

(efficiency req) •  Pipe sizing requirements •  Energy recovery

requirements •  Testing and balancing

requirements

Select your path for compliance

ASHRAE 90.1: Service hot water heating

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Satisfy mandatory provisions: Must perform load calculations •  ASHRAE Handbook

Other items: •  Minimum efficiency •  Temperature controls •  Pump controls •  Heat traps

Select your path for compliance

ASHRAE 90.1: Power

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Satisfy mandatory provisions: •  Efficiency for transformers •  Automatic control

requirements

ASHRAE 90.1: Lighting

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Satisfy mandatory provisions: •  Automatic control requirements •  Power density requirements

Select your path for compliance

GREEN BUILDING STANDARDS AND RATING SYSTEMS

Moving beyond baseline performance …

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LEED: Leadership in Energy and Environmental Design

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System of 110 possible points; •  Site (26) •  Water (10) •  Energy and atmosphere (35) •  Materials and resources (14) •  Indoor environmental quality (15) •  Innovation in design (6) •  Regional priorities (4)

System of 136 possible points; •  Innovation and design (11) •  Location and linkages (10) •  Sustainable sites (22) •  Water efficiency (15) •  Energy and atmosphere (38) •  Materials and resources (16) •  Indoor environmental quality (21) •  Awareness and education (3)

LEED and energy use

•  USGBC LEED-NC 2009 –  “NC” = new construction

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LEED and energy use

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LEED and energy use

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ASHRAE Advanced Energy Design Guides

•  Targets of 30% energy savings or 50% energy savings –  Over ASHRAE 90.1-1999

•  Guidelines for many types of buildings: –  Medium to big box retail buildings –  Small to medium office buildings –  K-12 school buildings –  Large hospitals –  Small office buildings –  Highway lodging –  Small warehouses –  etc.

•  You can download most of these for free –  http://aedg.ashrae.org/GetSubscription.aspx

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ASHRAE AEDG: 30% savings in small offices

•  Office buildings smaller than 20,000 ft2

•  Only a recommendation document –  Not a code or standard (unless a standard implements this)

•  Represents “a way” to build energy efficient small offices •  Recommendations for energy-efficiency in:

–  Building envelope –  Lighting –  HVAC equipment and systems –  Service water heating

•  Focus on integrated process

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ASHRAE AEDG: 30% savings in small offices

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ASHRAE AEDG: 50% savings in small offices

•  Similar to the 2004 30% guide but more stringent –  Target: 50% lower energy than ASHRAE 90.1-2004

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ASHRAE AEDG: 50% savings in small offices

•  Recommendations by climate: Zone 6

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Do LEED buildings save energy?

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Do LEED buildings save energy?

•  3 reports…

34 New Buildings Institute 2008

Scofield 2009

Newsham et al. 2009

Do LEED buildings save energy?

35 New Buildings Institute 2008

Do LEED buildings save energy?

36 New Buildings Institute 2008

Do LEED buildings save energy?

37 New Buildings Institute 2008

Do LEED buildings save energy?

38 Newsham et al. 2009 Energy and Buildings

Do LEED buildings save energy?

39 Scofield 2009 Energy and Buildings

Do LEED buildings save energy?

40 Oates and Sullivan 2012 J Const Eng Mgmt

Finally: ASHRAE 189.1

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ASHRAE 189.1

•  Mandatory provisions •  Prescriptive options •  Performance options

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ASHRAE 189.1: Energy efficiency provisions

Mandatory •  Must comply with ASHRAE 90.1 •  Must have space for future on-site renewables •  Must collect energy use data

Prescriptive •  Requirements in 189.1 supersede 90.1 •  Must have on-site renewables (20 kWh/m2)

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ASHRAE 189.1: Envelope requirements

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ASHRAE 189.1: Envelope requirements

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Passive House

•  A Passive House is a very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people and equipment

•  Performance characteristics: –  Annual heat requirement less than 15 kWh/m2 (4.75 kBTU/ft2) –  Primary energy less than 120 kWh/m2 (38.1 kBTU/ft2) –  Window U-value less than 0.8 W/m2K (0.15 Btu/hrft2F) –  Ventilation system with heat recovery greater than 75% –  Airtight shell: 0.6 ACH @ 50 Pa –  Thermal bridge free construction

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COURSE RE-CAP

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Day 1: Course information

Course Catalog Description •  Study of the physical interaction of climate (humidity,

temperature, wind, sun, rain, snow, etc.) and buildings. Topics include psychrometrics, indoor air quality, indoor thermal comfort, heat transfer, air infiltration, solar insolation, and heating and cooling load calculation.

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Day 1: Course objectives

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To introduce students to physical phenomena that affect building design and performance. By taking this course students will be able to:

1.  Describe the role of building components and building environmental systems in energy consumption, peak electricity demand, thermal comfort, and human exposures to pollutants.

2.  Describe the role of buildings and environmental systems in building design, construction, and operation.

3.  Describe and quantify fundamental heat and mass transfer properties and processes in buildings, including conduction, convection, radiation, psychrometrics, thermodynamics of refrigeration systems, fluid flow, and mass balances.

4.  Calculate peak heating and cooling loads for buildings. 5.  Understand types of HVAC equipment for residential and commercial construction

and how they operate. 6.  Understand basic ventilation and indoor air quality concepts. 7.  Understand basic concepts of building diagnostic tests, acoustics, and lighting. 8.  Critically analyze claims about building components and environmental systems

from product manufacturers, contractors, and building designers.

Day 1: Course topics (and final exam coverage)

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•  Importance of building science •  Elements of heat transfer in buildings •  Building energy balances •  Psychrometrics •  Thermal comfort •  HVAC systems and thermodynamics •  Mechanical, electrical, plumbing, and lighting systems •  Ventilation, infiltration, and indoor air quality •  Fluid flow in buildings •  Heating and cooling loads •  Building performance diagnostics, acoustics, and lighting •  Energy efficiency and green buildings

Courses with building science elements at IIT

•  Enclosure/architectural/energy –  CAE 463/524 Building Enclosure Design –  CAE 446/556 and CAE 447/557 Net Zero Energy Home Design Competition

•  Two part course: Fall 17 + Spring 18 –  CAE 515 Building Energy Modeling –  EG 430 Building Information Modeling –  CAE 442/542 Applied Building Energy Modeling (Hopefully Spring 2017)

•  Mechanical/environmental –  CAE 464 HVAC Design –  CAE 465/526 Energy Conservation Design in Buildings –  ENVE 576 Indoor Air Pollution

•  Electrical/lighting –  CAE 466/528 Building Electrical Systems Design –  CAE 467/521 Lighting Systems Design

•  Plumbing and fire protection –  CAE 424/510 Fire Dynamics –  CAE 425/511 Fire Protection and Life Safety in Building Design –  CAE 461 Plumbing and Fire Protection Design

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Thank you for being a good class!

•  And remember to fill out your course evaluations!

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