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 tillerjs@appstate.edu Robert Powell North Carolina A&T Architectural Engineering rpowell@ncat.edu

Question for Today Given the mandates of Senate Bill 668, how do you design the building envelope to optimize energy efficiency? NC State Construction Office 2

Defining The Building Envelope NC State Construction Office 3

What are the functions of the Building Envelope? NC State Construction Office 4

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

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

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.

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.

Other “Green” Criteria Adaptable Durable Affordable Environmental Healthy NC State Construction Office 9

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 NC State Construction Office 10

Integrated Design: Assess the Site Evaluate centrality to the community Evaluate access to public transportation Identify on-site energy opportunities Identify best building orientation

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

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

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

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

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

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.

Two Sets of Requirements – multiple pathways to compliance Chapter 5: Commercial Energy Efficiency ASHRAE 90.1-2004 in the North Carolina energy code IECC 2006 – with local amendments

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

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!

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

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

High Rise Residential – Which Energy Code? 23

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

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

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.

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

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

Return Plenum Problems - Canopy

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

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

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.

Climate

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

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

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

Common R-values – Resistance to Conductive Heat Flow Concrete 0.2 per inch ½” Drywall 0.5 Double-paned glass 1.8 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

Steel Framing and Insulation

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

U-factors for Metal Stud Walls

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

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

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.

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

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

4 Classes of floor construction Floor Insulation (5.5.3.4) 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.

Roof Insulation Requirements: ASHRAE 90 Roof Insulation Requirements: ASHRAE 90.1-2004 (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

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

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

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

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”

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

Commercial Wall Requirements: ASHRAE 90 Commercial Wall Requirements: ASHRAE 90.1-2004 (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

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

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

Typical? Non-Compliant!

How about now?

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)

NFRC Label

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.

Commercial Floor Requirements: ASHRAE 90 Commercial Floor Requirements: ASHRAE 90.1-2004 (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

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

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

Fenestration Performance Section 5.8.2 NFRC Rating for all Manufactured Fenestration U-factor SHGC Air Leakage No label? = Default Tables 102.5.2(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!

IECC 2006 Commercial Glazing Requirements

ASHRAE 90.1 Fenestration Requirements for Climate Zones 3 and 4 66

4 Building Envelope Considerations Materials Building Assemblies Process Design Performance ASHRAE Advanced Energy Guidelines as a Model NC State Construction Office 67

Materials Building Skin Insulation Radiant Technologies Moisture Control Materials NC State Construction Office 68

Building Assemblies Wall Systems Rain Screens Roof/Attic Systems Energy Services/Supply Envelope Component Integration Advanced Panel/Prefabrication Intelligent Envelope Systems NC State Construction Office 69

Process and Design Daylight and Passive Solar Modular Coordination Natural Ventilation Recycling/Reuse Processes Regional Design NC State Construction Office 70

Performance Performance Modeling/Testing Performance Monitoring/Testing Performance Rating Criteria NC State Construction Office 71

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