CAE 331/513 Building Science Fall 2016

Transcription

1 CAE 331/513 Building Science Fall 2016 Week 15: December 1, 2016 Standards and guidelines for energy efficiency Advancing energy, environmental, and sustainability research within the built environment Dr. Brent Stephens, Ph.D. Civil, Architectural and Environmental Engineering Illinois Institute of Technology

2 Schedule Graduate students: Final reports due Thurs Dec 1 st, 11:59 pm Move to Monday 8 am All: HW 6 due Thurs Dec 1 st in class Can turn in by Friday by 5 pm without any points off Final exam (all students): December 8 th, 2-4 pm 2

3 Last time: Building energy simulation There are many software packages available (some are free) EnergyPlus equest IES-VE TRNSYS Many others tools_directory/subjects.cfm/ pagename=subjects/ pagename_menu=whole_building_analysi s/pagename_submenu=energy_simulation 3

4 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 At surface nodes: q = 0 C Heat external surfaces: Radiation and convection At nodes inside materials: dt mc p dt = q at boundaries Unsteady conduction (storage) is based on density and heat capacity of material 1 2 L 3 Room F Convection A air node Rad iati on 3 internal surface node 2 element-inner node 1 external surface node 3 2 R 1 4

5 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) (V room ρ air c p,air ) dt air,in dt n = h i A ( i T i,surf T ) air,in + mc p T out T air,in i=1 ( ) +Q HVAC 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 L 3 C 3 F 3 A air node EQ i HVAC R 3 Q infiltration 5

6 Energy efficiency is actually inexpensive $520 billion in investment à $1.2 trillion in savings through 2020 McKinsey & Company, 2009 Unlocking energy efficiency in the US economy 6

7 BUILDING DESIGN GUIDELINES AND STANDARDS 7

8 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 8

9 State energy codes: Commercial buildings 9

10 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 10

11 ASHRAE , 2010, 2013, and now 2016 Energy Standard for Buildings Except Low-Rise Residential Buildings Look for Addenda to the standard Corrections and changes 11

12 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 12

13 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 13

14 ASHRAE 90.1: Table of contents 14

15 ASHRAE 90.1: Climate zone specific Select your climate zone 15

16 ASHRAE 90.1: Building envelope Satisfy mandatory provisions: Sealant requirements Locations where joints must have sealants applied Select your path for compliance Air leakage Maximum air leakage of doors and windows Vestibule entrances Requirements for the use of vestibules or revolving-doors at an entrance 16

17 ASHRAE 90.1: Building envelope (IP) Prescriptive path: Requirements for U, R, and SHGC for enclosure elements 17

18 ASHRAE 90.1: Building envelope (IP) Prescriptive path: Requirements for U, R, and SHGC for enclosure elements 18

19 ASHRAE 90.1: HVAC Satisfy mandatory provisions: Must perform load calculations ASHRAE Standard 183 Radiant time series or heat balance method Select your path for compliance 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 19

20 ASHRAE 90.1: Service hot water heating Satisfy mandatory provisions: Must perform load calculations ASHRAE Handbook Select your path for compliance Other items: Minimum efficiency Temperature controls Pump controls Heat traps 20

21 Satisfy mandatory provisions: Efficiency for transformers Automatic control requirements ASHRAE 90.1: Power 21

22 ASHRAE 90.1: Lighting Satisfy mandatory provisions: Automatic control requirements Power density requirements Select your path for compliance 22

23 Moving beyond baseline performance GREEN BUILDING STANDARDS AND RATING SYSTEMS 23

24 LEED: Leadership in Energy and Environmental Design 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) 24

25 USGBC LEED-NC 2009 NC = new construction LEED and energy use 25

26 LEED and energy use 26

27 LEED and energy use 27

28 ASHRAE Advanced Energy Design Guides Targets of 30% energy savings or 50% energy savings Over ASHRAE 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 28

29 ASHRAE AEDG: 30% savings in small offices Office buildings smaller than 20,000 ft 2 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 29

30 ASHRAE AEDG: 30% savings in small offices 30

31 ASHRAE AEDG: 50% savings in small offices Similar to the % guide but more stringent Target: 50% lower energy than ASHRAE

32 ASHRAE AEDG: 50% savings in small offices Recommendations by climate: Zone 6 32

33 Do LEED buildings save energy? 33

34 3 reports Do LEED buildings save energy? Newsham et al Scofield 2009 New Buildings Institute

35 Do LEED buildings save energy? New Buildings Institute

36 Do LEED buildings save energy? New Buildings Institute

37 Do LEED buildings save energy? New Buildings Institute

38 Do LEED buildings save energy? Newsham et al Energy and Buildings 38

39 Do LEED buildings save energy? Scofield 2009 Energy and Buildings 39

40 Do LEED buildings save energy? Oates and Sullivan 2012 J Const Eng Mgmt 40

41 Finally: ASHRAE

42 ASHRAE Mandatory provisions Prescriptive options Performance options 42

43 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 supersede 90.1 Must have on-site renewables (20 kwh/m 2 ) 43

44 ASHRAE 189.1: Envelope requirements 44

45 ASHRAE 189.1: Envelope requirements 45

46 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/m 2 (4.75 kbtu/ft 2 ) Primary energy less than 120 kwh/m 2 (38.1 kbtu/ft 2 ) Window U-value less than 0.8 W/m 2 K (0.15 Btu/hrft 2 F) Ventilation system with heat recovery greater than 75% Airtight shell: Pa Thermal bridge free construction 46

47 COURSE RE-CAP 47

48 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. 48

49 Day 1: Course objectives 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. 49

50 Day 1: Course topics (and final exam coverage) 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 50

51 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 51

52 Thank you for being a good class! And remember to fill out your course evaluations! 52