Sponsored by: State Energy Office

1
The North Carolina Energy Code Commercial
Requirements
Sponsored by State Energy Office National
Governors Association, North Carolina
Governors Office, American Institute of
Architects NC Dept of Insurance Conducted
by
Appalachian State UniversityDept. of Technology
Energy Center Boone, NCJeff Tiller, PE,
tillerjs_at_appstate.edu
Chris Mathis and AssociatesAsheville, NC
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Total Energy Use by Sector (TBtu)
2004
1960
3
Structure of 2006 NC Code

• Chapter 1 General/Administrative Enforcement
• Chapter 2 Definitions
• Chapter 3 Design Conditions
• Chapter 4 Residential Energy Efficiency
• Chapter 5 Commercial Energy Efficiency
• Chapter 6 Referenced Standards

4
SCOPE

• When does the NCECC apply?
• Newly conditioned space
• New construction in existing buildings
• Alterations to existing spaces
• Additions
• Mixed use buildings
• Change in occupancy

5
Change In Occupancy

• Alterations to Existing Spaces
• Applies to only portions of the systems being
  altered
• Applies if alteration increases energy use
• Alterations must meet the requirements
  applying to the altered component
• New systems in the alterations must comply

6
Two Sets of Requirements multiple pathways to
compliance

• Building Design for All Commercial Buildings
• ASHRAE 90.1-2004 in the North Carolina energy
  code
• Design by Acceptable Practice for Commercial
  Buildings
• Chapter 5 part of the IECC 2006 with local
  amendments

7
Typical Commercial Building Energy Consumption
Patterns
8
Section 5Envelope Mandatory Provisions
Section 5.4

• 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

9
Section 5 Envelope, contd 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

10
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
11
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

12
Is Air Barrier Continuous?

• Brand-new NC building
• Drywall leftoff of exteriorwall abovedropped
  ceiling
• Building usesabove-ceiling areaas return
• When HVAC operates, entire wall cavity goes to a
  negative pressure, increasing air leakage,
  effectively reducing insulation value, and
  potentially causing moisture problems

13
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)

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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.

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Section 5 - Prescriptive Requirements, Building
Envelope
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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

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2009 IECC Climate ZonesZones 4 and Below Dont
Require Wall Vapor Barriers (Only NW Mountains
need one)
18
2009 NC Energy Code Climate Zones
Zone 34 No VB
Zone 5 VB Required
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• NORTH CAROLINA ZONES
• Zone 3 except
• Zone 4
• Alamance
• Alexander
• Bertie
• Buncombe
• Burke
• Caldwell
• Caswell
• Catawba
• Chatham
• Cherokee
• Clay
• Cleveland
• Davie
• Durham
• Forsyth
• Franklin

Graham Granville Guilford Halifax Harnett Haywood
Henderson Hertford Iredell Jackson Lee Lincoln Mac
on Madison McDowell Nash Northampton Orange Person
Polk Rockingham Rutherford Stokes Surry Swain Tran
sylvania Vance Wake Warren Wilkes Yadkin Zone
5 Alleghany Ashe Avery Mitchell Watauga Yancey
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NC Energy Code Chapter 5 Prescriptive
21
Roof Insulation Requirements IECC 2003 (Chapter
8 of current code)
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Roof Insulation RequirementsASHRAE 90.1-2004
(Chapter 7 of current code and Chapter 5, section
501 of new code)
23
Building Envelope Example Roofs
No longer counts Batts over suspended ceiling
tiles
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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
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Commercial Wall Insulation Requirements IECC
2006 (Chapter 5 of new code)
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Steel Framing and Insulation
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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

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Steel Framed Walls
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U-factors for Metal Stud Walls
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Effective R-value of 2x4 Metal Framed Walls (16
o.c.)
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Wall Insulation
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How about now?
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Typical? Non-Compliant!
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Concrete Block Walls

• Concrete Masonry Units
• Insulation-filled CMU used to comply
• IECC 2006 The R-value of integral insulation
  installed in concrete masonry units (CMU) shall
  not be used in determining compliance with Table
  502.2(1)

35

• Field Inspection of Big Box Retail Store in
  Boone, NC

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Glazing Area Percentage

• Glazing percentage to Above Grade Wall
• Gross window area / gross wall area
• Gross wall area includes
• Above-grade walls
• Band joist and subfloor between floors
• Area of all doors and windows

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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
Projection Factor (PF)
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NFRC Label
39
IECC 2006 Commercial Glazing Requirements (new
code)
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ASHRAE 90.1 Fenestration Requirements for Climate
Zones 3 and 4
Note ASHRAE 90.1-2004 is an option for the
current and new codes
41
Window Wall Fraction
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Section 6 HVAC Key Concepts

• Goal a system which minimizes system losses
  and utilizes free heating and cooling
• Scope and Compliance Paths
• Establish minimum equipment efficiencies
• Establish a min. level of control for systems
• Establish minimum levels of construction and
  insulation of systems.
• Simplified Approach/Prescriptive Path
• Submittals

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Simplified HVAC Approach Option

• Limited to buildings that meet the following
  criteria
• buildings with 1 or 2 stories
• buildings lt 25,000 ft2
• single-zone systems
• Unitary packaged or split system air-cooled or
  evaporatively-cooled only equipment efficiencies
  per tables
• Economizer if required
• Outside air requirements are less than 3000 CFM
  and less than 70 of airflow
• Manual changeover or dual set-point thermostat
• Heat pump supplementary control
• No reheat or simultaneous heating and cooling for
  humidity control

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Example 25-ton Cooling Efficiency

• Cooling efficiency
• 25 tons 300,000 Btuh

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Example 25 ton Heating
Heating efficiency 25 tons 300,000 Btuh
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Example 25 ton Controls

• Electronic, 7-day, thermostat can meet the
  following requirements
• Dual setpoints for heating and cooling modes
• Off-hour shutoff
• Setback capability
• Start-up (set up)

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Example 25 ton Duct Insulation
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Example 25 ton Ducts

• Table 6-D in User Manual
• R-3.5 1-inch duct liner, fiberboard, duct board,
  flex duct 1.5-inch mineral fiber duct wrap
• R-6.0 1.5-inch duct liner, fiberboard, duct
  board, flex duct 2.5-inch flex duct, mineral
  fiber duct wrap
• R-8.0 2-inch duct liner, fiberboard, duct board,
  flex duct 3-inch flex duct, mineral fiber duct
  wrap
• Duct Sealing Required (to be discussed later)

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Example 25 ton Other

• Air Balancing add note to the design drawings
  or specs calling for balancing according to
  ASHRAE 111, NEBB, AABCm or other
  industry-recognized standard
• Since no fan exceeds 300 cfm, a backdraft damper
  is not required per 6.2.3.3.3

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ASHRAE / IESNA 90.1-2001HVAC Mandatory Provisions

• Applies to the Prescriptive Path and the Energy
  Cost Budget method
• Requirements address
• Life cycle cost analysis
• Equipment efficiencies
• Load calculations
• Controls
• Construction and insulation
• Completion requirements

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Section 6 Load Calculations

• Load Calculations are required!
• Ask for them!

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Section 6 Mandatory Provisions-Controls

• Off-Hour controls (note exceptions under
  6.4.3.2)
• Automatic Shutdown (PGM T-stat OS Timer
  Interlock)
• Setback Controls (by climate zone - 55F heating
  90F cooling)
• Optimum Start Controls (gt10,000 cfm)
• Zone Isolation

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More Mandatory Provisions

• They cover
• Heat pump controls
• Humidifier and dehumidifier controls
• Freeze/Thaw protection
• Snow/Ice melting
• Ventilation controls

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Even MORE Mandatory Requirements

• Record drawings
• Operating and Maintenance Manuals
• System Balancing (Air and Water)
• System Commissioning (50,000 sf threshold)
• Good Design Practice

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Section 9 - Lighting

• Use current lighting product performance data and
  current new building construction data
• Apply current lamp/ballast efficacy and light
  loss factors and incorporate IES recommended
  light levels
• Apply professional lighting design consensus of
  quality lighted environments
• Combine these elements into building space models
  to calculate lighting power densities
• Use controls

Key Concepts
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Section 9Lighting General Scope

• Applies to lighting for
• Interior spaces
• Exterior building features (facades, roofs,
  entrances, exits, loading docks, canopies)
• Exterior building grounds provided thru the
  buildings electrical service

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Occupancy Sensors
Section 9.4.1.2

• For high usage areas with irregular schedules
• Applications
• Private offices
• Classrooms
• Conference rooms
• Break rooms
• Restrooms

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Interior Lighting Controls

• Lighting controls required for each area enclosed
  by ceiling height partitions
• Switch locations
• In view of lights
• On or off indication from remote location
• Occupancy sensor

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Interior Lighting Controls

• Exceptions
• Emergency/security lighting
• Stairway or corridor lighting for egress

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Guest Rooms

• Master switch required at entry

• Standard Room

• Suite

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Exterior Lighting Controls

• Automatic switching or photocell controls shall
  be provided for all exterior lighting not
  intended for 24-hour operation.
• Automatic time switches shall have a combination
• Seven-day and seasonal daylight program schedule
  adjustment
• A minimum 4-hour power backup

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Tandem Wiring

• Center to Center

• Exceptions
• Luminaires with electronic high-frequency
  ballasts
• Luminaires not on same switch controls or not in
  the same area

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Exit Signs

• Internally illuminated exit signs shall not
  exceed 5 Watts per side

• Section 805.4

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Lighting Power Densities Using the Building Area
Method
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Energy-Efficient Lighting Sources
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Total Connected Power

• Total connected lighting wattage includes
• Lamp wattage
• Ballast wattage
• Sources of bulb/ballast wattages
• Manufacturers literature
• Industry default tables
• Exceptions
• Specialized medical, dental, and research
  lighting
• Professional sports arena playing field lighting
• Display lighting for gallery exhibits, museums,
  and monuments
• Guest room lighting in hotels, motels, boarding
  houses, or similar buildings
• Emergency lighting automatically off during
  normal building operation

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Does the Building Comply?

• Determine the total connected power in watts for
  the proposed lighting
• Determine the interior lighting power budget for
  the entire building or space
• Building complies if
• Interior lighting power budget - total connected
  power ?0

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Exterior Lighting

• Criteria
• Lighting power supplied through building
  electrical service
• Must use energy-efficient lighting sources to
  highlight paths, walkways and parking areas
• ? 45 Lumens/Watt
• Fluorescent or Compact Fluorescent
• Metal Halide or High Pressure Sodium
• Exceptions
• Historical
• Safety
• Signage
• Emergency

• Section 805.5/805.6

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Section 11Energy Cost Budget Method

• Alternative to prescriptive method except
  buildings with no mechanical systems
• Based on overall building performanceexpressed
  as energy cost budget
• Mandatory Provisions all must be met
• Budget (or baseline) based on prescriptive
  measures
• Allows trade-offs between measures
• Useful for optimizing design

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Key Points to Check

• Envelope
• Insulation values correct? Proper installation?
• Fenestration -- glass
• Fenestration U-factor and SHGC (on plans and
  in field)
• Air sealing details
• HVAC
• Programmable controls?
• Economizer?
• Duct and pipe insulation?
• Ducts sealed?

1/28/2008
Mathis Consulting Company
Page 70
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Key Inspection Points (cont.)

• HVAC (continued)
• No simultaneous heating and cooling (except where
  allowed for reheat)
• Complex systems
• Fan power
• Temperature reset
• Zoning
• Reheat limitation
• Etc.

1/28/2008
Mathis Consulting Company
Page 71
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Key Inspection Points (cont.)

• Lighting
• If most lamps are not T-8 fluorescent or more
  efficient lamps, need to check
• Check controls -- occupancy and daylighting
  controls
• Exit signs
• Exterior lighting efficiency and controls

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So, What Now?

• In Commercial, Appendix B is not enough
• Plan review and inspection of energy features is
  needed

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ASHRAE 90.1 Advanced Design Guide Office
Building
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ASHRAE 90.1 Advanced Design Guide Office
Building
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ASHRAE 90.1 Advanced Design Guide Office
Building
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ASHRAE 90.1 Advanced Design Guide Office
Building