1. North Carolina State Buildings Efficiency Conference
Requirements to Meet Senate Bill 668
Sponsored by: State Energy Office and State Construction Office
NC Department of Administration
Conducted by:
Introduce yourself and give a brief background of who you are and why you are qualified to teach the course.
Questions:What is the audiences involvement in the building process?
How many have worked with the IECC/MEC in the past?
How many have used or have reviewed the RESCheck compliance materials?
Use this time for general housekeeping announcements.
Jeff Tiller, PE Appalachian State University Dept. of Technology & Energy Center
Boone, NC
Robert Powell North Carolina A&T
Architectural Engineering

2. Question for Today
Given the mandates of Senate Bill 668, how do you design the building envelope to optimize energy efficiency?
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3. Defining The Building Envelope
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4. What are the functions of the Building Envelope?
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5. Section 5 – Envelope Building envelope does not use energy
Key Concepts
Building envelope does not use energy
Design affects heating and cooling loads
Insulation affects the temperature of inside surfaces; comfort
Daylighting can reduce electric lighting

6. Section 5 – Envelope, cont’d
Integrated design approach saves energy
Building envelope requirements address:
Opaque elements
Roofs, walls, floors, below-grade walls, slabs, opaque doors
Fenestration
Windows, doors, skylights
How often do we get the chance to get this part of the building right?
Standard 90.1 sets minimum level of thermal performance thru opaque elements
Limits solar gain through fenestration

7. Section 5 – Envelope, cont’d Air Leakage
…..Building envelope shall be sealed, caulked, gasketed or weather-stripped to minimize air leakage.
Seams between panels
Joints between systems
Joints around penetrations
The last and probably one of the most overlooked mandatory aspect of energy conservation is air infiltration. The standard only loosely and generally discusses this topic and depends on professional judgement. That said, we know that air infiltration is a major source of energy lose and can be improved upon dramatically. I do not have time to go into all the details, but the recent studies have shown that contrary to the belief that buildings are tight they are in fact, surprisingly drafty. How do we do this, seams, joints, and penetrations.

8. Building Envelope – Key Targets
Building design
Shape and orientation
Glazing
Passive solar design
Daylighting
Building structure
Insulation
R-values
Installation
Fenestration (glazing)
U-factor
Solar Heat Gain Coefficient
Air leakage/ ventilation control
Trainers:
Here we will offer “Solutions” first. We will speak to known problems and ways that builders can avoid them (or solve them).
We will also focus on the solutions as MONEY – currently money wasted by the builder in each of the subject areas.

9. Other “Green” Criteria
Adaptable
Durable
Affordable
Environmental
Healthy
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10. Integrated Design Process
Site Considerations
Reduce Loads
Size Systems Properly for Reduced Loads
Incorporate Efficient Equipment and Systems
Refine System Integration
ASHRAE Advanced Energy Guidelines as a Model
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11. Integrated Design: Assess the Site
Evaluate centrality to the community
Evaluate access to public transportation
Identify on-site energy opportunities
Identify best building orientation

12. Identify on-site energy opportunities
Integrated design begins with site assessment and selection
Site selection is an opportunity to obtain free energy resources

13. Reduce loads on energy-using systems
Reduce Internal Loads
More efficient equipment, appliances and lighting
Reduce heat gain/loss through the building envelope: many options, see next slides
Reduce Thermal Loads:
Utilize Passive Solar Design, Thermal Storage
Refine building to suit local conditions
Operable Windows, cross ventilation

14. Reduce Heat Gain/Loss
Control Solar Gain to reduce cooling load through windows
Use beneficial building form and orientation
Minimize windows east and west, maximize windows north and south
Use glazing with low solar heat gain coefficient (SHGC)
Provide external shade glazing to reduce solar heat gain and glare
Use vegetation on S/E/W to control solar heat gain and glare

15. Reduce Heat Gain/Loss
Reduce Solar Gain through opaque surfaces to reduce cooling load
Increase Insulation of opaque areas
Increase Roof surface reflectance and emittance
Shade building surfaces with deciduous and coniferous trees as appropriate for surface orientation

16. Reduce Heat Gain/Loss
Reduce Conductive Heat Gain and Loss through building envelope
Increase Insulation on roof, walls, floors, slabs and doors and decrease window U factor
Reduce air infiltration
Provide continuous air barrier
Reduce Heat Gain or Loss from ventilation exhaust air
Use energy recovery to precondition outdoor air

17. Structure of 2009 NC Code (based on IECC 2006)
Chapter 1 Administration
Chapter 2 Definitions
Chapter 3 Climate Zones
Chapter 4 Residential Energy Efficiency
Chapter 5 Commercial Energy Efficiency
Chapter 6 Referenced Standards
Index
Trainers:
The IECC is organized as follows:
We will just be focusing on Residential today
Mention commercial, especially where relevant in that state.

18. Two Sets of Requirements – multiple pathways to compliance
Chapter 5: Commercial Energy Efficiency
ASHRAE in the North Carolina energy code
IECC 2006 – with local amendments

19. Organization of ASHRAE Standard 90.1-2004
1 Purpose
2 Scope
3 Definitions
4 Administration and Enforcement
5 Building Envelope
6 Heating, Ventilating, and Air-Conditioning
7 Service Water Heating
8 Power
9 Lighting
10 Other Equipment
11 Energy Cost Budget Method
12 Normative References

20. Section 1 - Purpose
The purpose of this standard is to provide minimum requirements for the energy- efficient design of buildings except low-rise residential buildings.
FYI, ASHRAE just published the 2007 version and most of the performance minimums have changed!
So stay tuned for even MORE fun!

21. Section 2 - Scope New buildings and their systems
New portions of buildings and their systems (additions)
New systems and equipment in existing buildings (alterations)
Note, chapter 2 deals with scope and is very brief, how the standard applies is in chapter 4

22. Section 2 – Scope Limitations
Does not apply to single family, or low-rise (3 story or less) residential
Building systems that use energy for process or industrial use

23. High Rise Residential – Which Energy Code?23

24. Section 5 Envelope Compliance Methods
Mandatory Provisions
Prescriptive Option
Trade-Off Option
Energy Cost Budget
Mandatory provisions must be met regardless of which compliance method is followed.
Compliance

25. Section 5 - Prescriptive Requirements, Building Envelope
3- the character of the space and its adjacencies, is it conditioned (heated or cooled), semi-heated, or unconditioned

26. Section 5 Envelope Mandatory Provisions
Air leakage
Building envelope sealing
Fenestration (windows and exterior glass)
NFRC 400*
1.0 cfm/ft2
0.4 cfm/ft2
Loading Docks
Vestibules
* NFRC = National Fenestration Rating Council
Insulation-see 5.8
Installation per manufacturers instructions
Substantial contact with adjacent surfaces (to limit air movement in cavity)
exception for radiant foils
Provisions discussing installation around recessed equipment such a cabinet heaters in a vestibule or recessed cans
Windows and Doors see 5.8
Requires they all meet NFRC standards for U-factor, SHGC, VLT and Air infiltration
Now this is particularly tricky for site built systems such a storefront systems, where the glass is from one manufacturer, the alum. Framing from another and the unit built by the glazing contractor. This is also covered by a NFRC standard , NFRC 100.
to summarize NFRC-100, because this a common assembly, you or the glazing contractor, send the glass information and the frame information to an accredited lab, where they simulate the assembly and issue a certificate of U-factor, SHGC and VLT.
Air Leakage
Not specific as to how, or how much, but more general in that one should caulk at joints between windows, doors and adjacent construction
Between dissimilar assemblies, control joints, expansion joints.
At mechanical / electrical / plumbing penetrations
Vestibules
Vestibules required at main building entry, but exceptions for size of lobby, height of building and climate zone.

27. 502.3 Basic Requirement: Air Leakage - Building Envelope Sealing
Caulk between wall panels particularly at corners and changes in orientation
Caulk around penetrations of chimney flue vents or attic hatches
Caulk around doors and windows
Caulk between wall arch floor where floor penetrates wall
Caulk between wall and roof
Caulk at penetrations of utility services or other service entry through walls floors and roofs
Caulk between wall panels and top and bottom plates in exterior walls
Caulk between wall and foundation
Weatherstrip doors

28. Major Air Leakage Sites
Cavities above suspended ceilings
Plenum return spaces (Highly depressurized)
Ventilated walls
Equipment tunnels and chases
Mechanical rooms and mezzanines
Unconditioned adjacent space (Storage, warehouse, plant, etc.)
Exhaust and ventilation fans, plus wind and stack effect, are major driving forces

29. Return Plenum Problems - Canopy

30. Is Air Barrier Continuous?
Brand-new NC building
Drywall left off of exterior wall above dropped ceiling
Building uses above-ceiling area as return
When HVAC operates, entire wall cavity goes to a negative pressure, increasing air leakage, effectively reducing insulation value, and potentially causing moisture problems

31. Limiting Air Leakage Pathways
Materials and connections must:
stop air flow
withstand jobsite abuses
withstand forces of wind and pressure
Penetrations must be sealed
plumbing, wiring, communications
ductwork
windows and doors
Functional penetrations, such as air intakes for exhaust fans, must be dampered
Vestibules (5 Stories or more, with exceptions)
air barrier is a system
it depends on the proper specification & installation of components, and connections between components

32. Section 5 – Envelope -- Vestibules
Required at building entrances
Self closing doors
Exceptions:
a. Building entrances with revolving doors.
b. Doors not used as a building entrance.
c. Doors opening directly from a dwelling unit.
d. Building entrances in buildings located in climate zone 1 or 2.
e. Building entrances in buildings located in climate zone 3 or 4 that are less than four stories above grade and less than 10,000 ft2 in area.
f. Building entrances in buildings located in climate zone 5, 6, 7, or 8 that are less than 1,000 ft2 in area.
g. Doors that open directly from a space that is less than 3,000 ft2 in area and is separate from the building entrance.

33. Climate

34. 2009 IECC Climate Zones: Zones 4 and Below Don’t Require Wall Vapor Barriers (Only NW Mountains need one)

35. 2009 NC Energy Code Climate Zones
Zone 3&4 – No VB
Zone 5 – VB Required

36. Section 5 – Prescriptive Requirements
Nonresidential
Commercial
Residential
Not one and two-family
Typically over 3 stories
Hotels and dormitories
Semi-Heated
2-the type of occupancy

37. Common R-values – Resistance to Conductive Heat Flow
Concrete per inch
½” Drywall
Double-paned glass
Low-e glass about 3.0
Fiberglass insulation 3 to 4 per inch
Cellulose insulation 3.7 per inch
Expanded polystyrene 4 per inch
Extruded polystyrene 5 per inch
Icynene foam 3.6 to 3.7 per inch
Polyurethane foam 6.7 to 7.0 per inch 37

38. Steel Framing and Insulation

39. Metal Framing Effects
Thermal bridging effect of metal framing must be accounted for in calculating U-factors
Outside Air Film
1- inch Exterior sheathing (R-3.8) with Stucco
2 x 4 Metal Studs with R- 13 in the Cavity
1/2 in. Gypsum Board
Inside Air Film

40. U-factors for Metal Stud Walls

41. Effective R-value of 2x4 Metal Framed Walls (16” o.c.)

42. Above Grade Floors – Is the Insulation Missing?
Continuous insulation is the key
1” of foam is vital for exposed slab edges
Heat loss will be more than just 4” of missing insulation
Trace other potential discontinuities in wall insulation system

43. Make Insulation Continuous
Block walls -- should be insulated; insulating cores very ineffective
Floors over unheated spaces, such as parking areas, need insulation
For discontinuities in walls, such as offset areas for stairwells, elevators, and other spaces, the exterior envelope must be determined. The envelope requires both insulation and air sealing.

44. Roof Insulation (5.5.3.1) 3 classes of roof construction
Insulation above
Metal buildings
Attic + Other

45. Above-Grade Wall Insulation (5.5.3.2)
5 Classes of wall construction
Mass
Metal Building
Metal Stud
Wood Stud
Below Grade
Mass walls is a heavyweight wall, generally weighing more than 15 lb/ft2. The technical definition is that the wall has a heat capacity greater than 7.0 Btu/ft2 F. for normal density mass materials and 5.0 Btu/ft1 F. for the light density mass materials. Comply with R-value criteria or U-factor requirement for the overall assembly, including thermal bridges
when a wall is both above grade and below grade and insulated on the interior, the above-grade insulation requirement applies to the entire wall
when insulation is installed on the exterior of the wall or is integral to the wall (e.g., the cells of a concrete masonry wall are filled) then the wall is divided between the above-grade and below-grade portions and the separate requirements apply to each

46. 4 Classes of floor construction
Floor Insulation ( )
4 Classes of floor construction
Mass
Steel Joist
Wood Joist
Slab on Grade Heated/Unheated
Mass floors are heavyweight floors, generally greater than 15 lb/ft 2. The technical definition of a mass floor is that the heat capacity be greater than 7.0 Btu/ft2 F. Or greater than 5.0 Btu/ft1 F. When using the R-value method, the insulation must be continuous and uninterrupted by framing members. Insulation sprayed to the underside of a concrete slab qualifies as continuous as long as it also covers structural supports such as steel beams or concrete girders. above the concrete slab.
Steel joist floors-Steel joist floors include any floor that is constructed with steel joists, but that does not qualify as a mass floor. If the floor has a heat capacity large enough to qualify it as a mass floor, then the mass class must be used. The steel joists that support the floor can be either open web joists or steel purlins. The key characteristics is that metal framing members interrupt the insulation. When a single R-value is given in the specification, this means that insulation with this thermal resistance must be installed between the joists and is therefore interrupted by the steel joists.
Wood framed-When the R-value method is used and only one R-value is specified, this refers to the thermal resistance of insulation installed between the wood joists. Insulating materials may be installed and supported so that the insulation is in direct contact with the bottom surface of the floor. When using the U-factor method, you must include the overall assembly and any thermal bridging effects.

47. Roof Insulation Requirements: ASHRAE 90
Roof Insulation Requirements: ASHRAE (Chapter 5, section 501 of new code)
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 47

48. Commercial Wall Insulation Requirements: IECC 2006 (Chapter 5 of new code)
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 48

49. Roof Insulation Requirements: IECC 2006
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 49

50. Building Envelope Example: Roofs
No longer counts: Batts over suspended ceiling tiles

51. Inspection is Critically Important!
Insulation specification was R-30 foam on roof deck according to the plans (and HVAC design)
The 2.5 inches found installed in the field would only provide about R-15
2.5”

52. Cool Roof (SRI - solar reflectance index)
Solar reflectance and emittance values from a lab accredited by the Cool Roof Rating Council
Insert chart

53. Commercial Wall Requirements: ASHRAE 90
Commercial Wall Requirements: ASHRAE (Chapter 5, Section 501 of new code)
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 53

54. Commercial Wall Insulation Requirements: IECC 2006 (Chapter 5 of new code)
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 54

55. Commercial Wall Insulation Requirements: IECC 2006 (Chapter 5 of new code)
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 55

56. Typical? Non-Compliant!

57. How about now?

58. Windows - SHGC Solar Heat Gain Coefficient
Requirements dependent on projection factor
National Fenestration Rating Council (NFRC) tested
Default SHGC range diagrams
SHGC = SC x .87
Solar Heat
Gain Coefficient
SHGC is a measure of how much solar gain is transmitted through the window by solar radiation
The lower the SHGC value of a window the less sunlight and heat can pass through the glazing.
The SHGC requirement is affected by overhangs on a building. The code uses the term projection factor to determine how well the overhang shades the glazing. The PF is calculated by measuring the distance from the window to the farthest-most edge of the overhang and dividing that by the distance from the bottom of the window to the lowest point of the overhang
The greater the PF the better the window is shaded. The better the window is shaded the less important the solar heat rejection qualities of the window. So a window with a higher SHGC value can be used to comply with the code.
If overhangs are shown on the building plans, ensure that they have been installed according to the design.
Projection Factor (PF)

59. NFRC Label

60. Skylights Restricted to ≤ 3% of roof area Requirements based on
U-value (NFRC tested) or
Default U-value table
A skylight U-factor is based on the interior-surface area of the entire assembly, including glazing, sash, curbing, and other framing elements. Center-of-glass U-factors cannot be used.
If an NFRC U-factor rating is available for the skylight, you should use its BB-size (ie, 48 by 48 in.) rating.
Buildings with skylight percentages over 3% of the gross roof area must use Chapter 7 or reduce the skylight area.

61. Commercial Floor Requirements: ASHRAE 90
Commercial Floor Requirements: ASHRAE (Chapter 5, Section 501 of new code)
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 61

62. Commercial Floor Requirements: IECC 2006 (Chapter 5 of new code)
And 4- the type of construction, wood frame, metal studs, masonry, etc.
Then you turn to the appropriate table and all of the required opaque and glazed thermal requirements are there. 62

63. Section 5 – Compliance Meet or exceed minimum R-values in Table 5.3
Only R-value of insulation, not to include air films, etc. OR
Meet maximum U-factor, C-factor, or F-factor for the entire assembly OR
Perform area-weighted average U-factor, C-factor, or F-factor

64. Fenestration Performance
Section 5.8.2
NFRC Rating for all Manufactured Fenestration
U-factor
SHGC
Air Leakage
No label? = Default Tables
(1)(2)(3)
Note: Default Tables ONLY work on performance path!
Trainers:
Note that the code already recognizes the recommendations we made earlier.
Select products with the NFRC label or be stuck with worst-case default values.
Accurate ratings have a big impcat on tradeoffs later!

65. IECC 2006 Commercial Glazing Requirements

66. ASHRAE 90.1 Fenestration Requirements for Climate Zones 3 and 466

67. 4 Building Envelope Considerations
Materials
Building Assemblies
Process Design
Performance
ASHRAE Advanced Energy Guidelines as a Model
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68. Materials Building Skin Insulation Radiant Technologies
Moisture Control Materials
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69. Building Assemblies Wall Systems Rain Screens Roof/Attic Systems
Energy Services/Supply
Envelope Component Integration
Advanced Panel/Prefabrication
Intelligent Envelope Systems
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70. Process and Design Daylight and Passive Solar Modular Coordination
Natural Ventilation
Recycling/Reuse Processes
Regional Design
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71. Performance Performance Modeling/Testing
Performance Monitoring/Testing
Performance Rating Criteria
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72. Outline from here ASHRAE 90.1 Design Guides
Orientation impact on energy use
Insulation measures impact on energy use
Glazing measures impact on energy use
Air sealing/ ventilation control impact on energy use
Impact of package of measures with energy management system/ lighting controls