Building Energy Codes Program Commercial Program Review

1
Residential Energy Code Compliance IRC 2000 IECC
2000/2001/2003
U.S. Department of Energy Building Energy Codes
Program
2
The Family of I-Codes
3
Structure of the IRC

• Building Envelope
• IRC Chapter 3
• Requirements for Insulation
• IRC Chapter 4
• Foundation waterproofing and dampproofing
• Foundation drainage
• Foundation venting
• IRC Chapter 5
• Shallow frost foundations
• IRC Chapter 7
• Weather resistant coverings for walls

• IRC Chapter 8
• Weather resistant coverings for roof assemblies
•  Mechanical System
• IRC Chapter 14
• Heating and cooling sizing calculations and
  sizing requirements

4
Relationship Between IRC and IECC

• Chapter 11Sets forth energy-efficiency related
  requirements for the design and construction of
  buildings..
• Section N1102.1 Residential Buildings, Detached
  One- and Two Family
• References IECC for buildings gt 15 gross wall
  area
•  Section N1102.2 Residential Buildings,
  Townhouses
• References IECC for buildings gt 25 gross wall
  area
•  Section N1103 Mechanical System
• References IECC Section 503.2 for HVAC Efficiency
•  Section N1104 Water Heating Efficiency
• References IECC Section 504.2 for water heating
  efficiency

5
Structure of the IECC

• Chapter 1 Administrative Enforcement
• Chapter 2 Definitions
• Chapter 3 Design Conditions
• Chapter 4 Residential - Systems Analysis
• Chapter 5 Residential - Component Performance
• Chapter 6 Simplified Prescriptive Requirements
• Chapter 7 ASHRAE 90.1-2001 Energy Code Reference
• Chapter 8 Design by Acceptable Practice for
  Commercial Buildings
• Chapter 9 Referenced Standards

Residential Chapters
6
Presentation Reference
Requirement covered by material is highlighted
in red.
Mandatory requirements such as moisture and
infiltration control must usually be met
regardless of location or design. Specific
requirements such as insulation levels are based
on the project location (HDD) and window wall
ratio.
Code year covered in current presentation.
Mandatory Requirements
2000/ 2001/ 2003 IECC
Mechanical
Section 501
6
Lighting
Envelope
Moisture
Infiltration
SHGC
Code Section
Requirements are outlined in Chapter 5 (Section
502.1) of the IECC.
Requirements can be met by the approaches in
Chapter 5 or the simplified tables of Chapter 6.
This presentation covers 2000/2001/2003 IECC
Residential Requirements New 2001/2003
requirements are listed in red.
7
Residential Compliance Outline
Current Presentation

• Overview of Residential Energy Codes
• Energy Code Compliance Options
• Energy Code Requirements
• Mandatory Requirements
• Specific Requirements
• Building Science Concepts
• Systems Design and the Code
• Compliance Using REScheck (Case Study)

Basic Code Compliance Presentation
Building Science/ Code Compliance Presentation
Case Study Presentation
For additional training materials see
www.energycodes.gov/training/presentations/
8
IECC Code Compliance Options
Prescriptive .
Total Building Trade Off
Energy Analysis
Individual Component Basis 502.2.1
Energy Analysis Chapter 4
Total Building UA 502.2.2
Not covered in this presentation.
Acceptable Practice 502.2.3
Prescriptive Specification 502.2.4
Simplified Prescriptive Chapter 6
9
Code Compliance Tools
Prescriptive .
Total Building Trade Off
Energy Analysis
Prescriptive Package Worksheet
(manual) Prescriptive Tables
Trade-off Worksheet (manual)
Software REMdesign REMrate EnergyGauge
REScheck Software (Web-based Desktop)
REScheck Package Generator (Web-based)
Not covered in this presentation.
10
Chapter 4 Residential Systems Analysis

• Requires a computer program
• Chapter 4 spells out additional essential types
  of input values (not applicable in REScheck),
  such as
• House tightness (measured by test for Final
  Rating projected for From Plans Rating)
• Window solar access and orientation evaluated
• Duct tightness evaluated
• Water heating (appliance Energy Factor)
• Thermal mass present

11
BECP Code Compliance Tools
Trade-off Approach
Prescriptive Approach

• Simple, fast and easy
• Generally most stringent
• Requires minimum input
• Based on climate and WWR
• Uses a prototype building

• Trade-off between components
• Provides design flexibility
• Requires area U/R-factors
• Uses UA calculation (REScheck) regression
  equations (COMcheck)

Residential
REScheck

• Prescriptive Tables Printed Guides
• REScheck Web Package Generator

• REScheck desktop software for Windows and Mac
  with AreaCalc tool
• REScheck-Web software

Web Based Tools
Commercial
COMcheck-EZ

• Prescriptive Tables / Printed Guides
• COMcheck Web Package Generator

• COMcheck-EZ desktop software for Windows
• COMcheck-Web software

Web Based Tools
12
Scope

• Detached one and twofamily dwellings
• R-2 (A-1) and R-4 (A-2) Residential Buildings
  containing 3 or more dwelling units where the
  occupants are permanent in nature and are 3
  stories or less in height
• Additions, including Sunrooms

Section 101
13
Exceptions

• Very low energy use buildings (lt3.4 Btu/h-ft2
  or 1 watt/ft2)
• Buildings (or portions of) that are neither
  heated nor cooled
• Buildings designated as historic (Section
  101.4.2.3)

Section 101.4.1
14
Changes to 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

Section 101.4.1
15
Mixed Use Buildings

• Minor occupancy
• lt10 of floor area
• Treat as major occupancy
• Hotel/motel and commercial occupancies
• Treat as different commercial occupancies
• Mixed residential and commercial occupancies
• Treat the residential occupancy under the
  applicable residential code
• Treat the commercial occupancy under the
  commercial code

Office
Residence
Apartments
Restaurant
Section 101.4.1
16
Building Envelope

• The intent of the energy code is to regulate the
  design of the building envelope to enable the
  effective use of energy.
• The Building Envelope separates conditioned space
  from unconditioned space or the outdoors.

attic
17
Building Envelope
18
Building Envelope Requirements

• 1) Mandatory Requirements
• Moisture Control
• Recessed Cans
• Infiltration Control
• Solar Heat Gain Coefficient
• 2) Climate Specific Requirements
• Foundations
• Basements
• Slabs
• Crawlspaces
• Above Grade Walls
• Skylights, Windows, and Doors
• Roofs

Section 502.1
19
Moisture Control

• Why a Vapor Retarder?
• Vapor travels from high pressure to low pressure.
  Moisture-laden air is literally "pushed" through
  penetrations in the building envelope. The
  moisture could damage the insulation and even the
  framing members, but a continuous vapor barrier
  helps prevent this from happening.

Section 502.1.1
20
Vapor Retarders Code Requirements

• Basic Requirements
• Install on warm-in-winter side of insulation
• Use in unvented framed walls, floors, and
  ceilings
• Must have perm rating of 1.0 per Procedure A of
  ASTM E 96

Section 502.1.1
21
Vapor Retarder - Exceptions

• Exceptions
• Climate Zones 1 through 7 (IECC Chapter 3)
• In construction where moisture or its freezing
  wont damage materials
• If other approved means to avoid condensation are
  provided

States with no vapor retarder requirements (IECC
2001)
Section 502.1.1
22
Vapor Retarders - Options
Kraft-faced Vapor Retarder
Poly Vapor Retarder
Section 502.1.1
23
Vapor Retarders - Examples
Section 502.1.1
24
Recessed Lighting Fixtures

• Type IC rated, with no penetrations between the
  inside of the recessed fixture and ceiling cavity
  (sealed and caulked)
• Type IC or non-IC rated, installed inside a
  sealed box of ½" gypsum wallboard or other
  assembly manufactured for this purpose
• Type IC rated, in accordance with ASTM E 283 to
  be an Air-Tight enclosure

Section 502.1.3
25
Recessed Lighting Fixtures
Section 502.1.3
26
What is Infiltration?

• Infiltration is the unwanted air movement through
  a building and is caused by a pressure difference
  (air moves from high pressure to a lower pressure)

Section 502.1.4
27
Areas for Air Leakage

• Windows and doors
• Between sole plates
• Floors and exterior wall panels
• Plumbing
• Electrical
• Service access doors or hatches

Section 502.1.4
28
Air Leakage Control

• Building envelope
• Sealed with caulking materials or
• Closed with gasketing systems
• Joints and seams sealed or taped or covered with
  a moisture vapor-permeable wrapping material

Section 502.1.4.2
29
Windows - SHGC

• Solar Heat Gain Coefficient
• Requirements can be dependent on projection
  factor
• National Fenestration Rating Council (NFRC)
  tested
• Default SHGC range diagrams
• SHGC SC x .87

Solar Heat Gain Coefficient
Section 502.1.5
30
Locations with SHGC Requirements
Section 502.1.5
31
SHGC Default Table
Table 102.5.2(3) SHGC DEFAULT TABLE FOR
FENESTRATION
Section 102.5.2
32
Specific Requirements

• 1) Mandatory Requirements
• Moisture Control
• Recessed Cans
• Infiltration Control
• Solar Heat Gain Coefficient
• 2) Specific Requirements
• Foundations
• Basements
• Slabs
• Crawlspaces
• Above Grade Walls
• Skylights, Windows, and Doors
• Roofs

Section 502.2
33
Envelope Requirement Compliance Options
Section 502.2 Heating and Cooling Criteria
Individual Component Basis 502.2.1
Acceptable Practice 502.2.3
Total Building Performance 502.2.2
Prescriptive Specification 502.2.4
Uo Graphs
Uo Tables from Appendix
Chap. 5 Prescriptive Tables
REScheck Software
Most Flexible Approach
Section 602.1 Thermal Performance Criteria
Simplified Prescriptive Tables
Use if WWR lt 15 for S.F., lt 25 for M.F.
Chap. 6 Prescriptive Tables
34
R-Values

• Thermal resistance to heat flow
• The larger the number the better
• The R-value of layers in an assembly can be added
  together

35
U-Factors

• The amount of heat in Btu (British thermal units)
  that flows each hour through one square foot,
  when there is a 1ºF temperature difference across
  the surface
• The smaller the number the better

36
Floors over Unconditioned Space

• Crawlspace is vented when the floor above is
  insulated.
• Meet or exceed R-value requirements.

Section 502.2/ 602.1
37
Supported Floor Insulation

• Support insulation in floor cavity

Section 502.2/ 602.1
38
Floors over Outside Air

• Floors over outside air must meet ceiling R-value
  requirements

Section 502.2/ 602.1
39
Crawlspace Wall Insulation
When crawlspace walls are insulated, foundation
vents are not required. Space should be
mechanically vented or conditioned.
Section 502.2/ 602.1
40
Vented Unvented Crawlspaces

• Vented Crawlspace Requirements
• The raised floor over the crawlspace must be
  insulated to the code R-value requirements for
  floors (varies by location).
• A vapor retarder may be required as part of the
  floor assembly (varies by location).
• Ventilation openings must exist that are equal to
  at least 1 square foot for each 150 square feet
  of crawlspace area and be placed to provide
  cross-flow (IRC 408.1, may be less if ground
  vapor retarder is installed).
• Unconditioned crawlspace ducts must be sealed and
  meet R-value insulation requirements (IECC Table
  503.3.3.3) - usually R-5.

• Unvented Crawlspace Requirements
• The crawlspace ground surface must be covered
  with an approved vapor retarder (e.g., plastic
  sheeting).
• Crawlspace walls must be insulated to the R-value
  requirements specific for crawlspace walls (IECC
  602.1.7, 502.2.1.5, and Table 602.1).
• Crawlspace wall insulation must extend from the
  top of the wall to the inside finished grade.
• Crawlspaces must be mechanically vented (1 cfm
  per 50 square feet) or conditioned (heated and
  cooled as part of the building envelope).

Section 502.2/ 602.1
41
Slab Edge Insulation

• Proposed R-value must meet or exceed
• Downward from top of slab a minimum of 24 (lt
  6000 HDD), 48 (gt 6000 HDD)
• Downward to at least the bottom of the slab and
  then horizontally 24 (lt 6000 HDD), 48 (gt 6000
  HDD)

Section 502.2/ 602.1
42
Slab Edge Insulation
Section 502.2/ 602.1
43
Below-Grade Walls

• ? 50 below grade
• Meet or exceed required R-values

Section 502.2/ 602.1
44
Defining Below-Grade Walls
Section 502.2/ 602.1
45
Ways to Insulate Basement Walls
Exterior Rigid Foam
Interior Studs w/batts
Section 502.2/ 602.1
46
Above Grade Walls
Insulate walls including those next to
unconditioned spaces
Dont forget to insulate rim joists
Section 502.2/ 602.1
47
Wall Insulation
Section 502.2/ 602.1
48
Knee Wall Insulation
No, No Never cut the batts too short
Section 502.2/ 602.1
49
Windows Glass Doors

• Key Elements
• Glazing Area
• SHGC values
• U-Values

Section 502.2/ 602.1
50
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
Section 502.2/ 602.1
51
Windows U-Factors
Table 102.3(1) U-Value Default Table for Windows
Glazed Doors and Skylights

• NFRC tested and certified
  or default window U-factor
  range
• Use assembly U-factor
• All windows must meet or exceed

Section 502.2/ 602.1
52
NFRC Label
New
Old
National Fenestration Rating Council (NFRC)
product ratings are available on-line at
www.nfrc.org
Section 502.2/ 602.1
53
Roofs

• Requirements based on
• Assembly type
• Continuous insulation
• Insulation between framing
• Meet or exceed R-values

Section 502.2/ 602.1
54
Standard Roof Truss
Possibility of ice dam formations

• Ceiling insulation code requirements assume
  standard truss systems

Cold corners contribute to condensation and mold
growth
Section 502.2/ 602.1
55
Raised Heel Truss

• Raised Heel/Energy Truss Credit
• Insulate full height over exterior wall

Section 502.2/ 602.1
56
Additions and Window Replacements

• Additions lt 500 ft2 can use Table 502.2.5
• Glazing area for additions (other than sunrooms)
  must be lt 40 of gross wall and roof area of
  addition
• Skylight replacements shall have a maximum
  U-factor of 0.60 when installed in climates gt
  1,999 HDD
• Fenestration replacement must meet the SHGC req.
  in locations lt3500 HDD

Section 502.2.5/ 602.4
57
Additions

• Compliance options for additions
• Treat as a stand-alone building
• Bring entire building into compliance

Section 502.2.5/ 602.4
58
Special Rules for Sunrooms

• Sunroom addition defined
• Area less than 500 ft2
• Have gt 40 glazing of gross exterior wall and
  roof area
• Separate heating or cooling system or zone
• Must be thermally isolated and not used as a
  kitchen or sleeping quarters

Section 502.2.5
59
Sunroom/Addition Requirements
2003 IECC Prescriptive Criteria Sunrooms
60
Mechanical Systems Equipment
61
Mechanical Systems Outline
503.1 General 503.2 Mechanical Equipment
Efficiency 503.3 HVAC Systems 503.3.1 Load
Calculations 503.3.2 Temperature and Humidity
Controls 503.3.2.1 System Controls 503.3.2.2
Thermostatic Controls 503.3.2.3 Heat
Pumps 503.3.3 Distribution Systems 503.3.3.1
Piping Insulation 503.3.3.2 Other Insulation
Thicknesses 503.3.3.3 Duct Plenum
Insulation 503.3.3.4 Duct Construction 503.3.3.4.1
High Medium Pressure Duct Systems 503.3.3.4.2
Low Pressure Duct Systems 503.3.3.4.3 Sealing
Required 503.3.3.5 Mechanical Ventilation 503.3.3.
6 Transports Energy 503.3.3.7 Balancing
Section 503
62
Mechanical Systems Overview
Major mechanical systems covered by the IECC
Section 503
63
Equipment Efficiencies

• Minimum equipment performance values from Table
  503.2
• Use data furnished by the manufacturer
• Performance data in accordance with NAECA
• National Appliance Energy Conservation Act
  (NAECA)
• Specifies equipment performance of heating and
  cooling equipment, water heaters, and other
  equipment
• Applicable equipment must meet NAECA before it
  can be sold in the United States

Section 503.2
64
Efficiency Terms

• Part Load Performance
• Annual Fuel Utilization Efficiency (AFUE) gas
  heating equipment
• Heating Seasonal Performance Factor (HSPF)
  residential heat pumps
• Seasonal Energy Efficiency Ratio (SEER)
  residential air conditioners

Section 503.2
65
Load Calculations

• Load Calculations
• Use design conditions specified in Chapter 3
• Calculations shall be performed in accordance
  with ASHRAE Handbook of Fundamentals or other
  equivalent method
• Systems shall be sized to meet the load

Section 503.3.1
66
Temperature and Humidity Controls

• 503.3.2.1 System Controls
• Each dwelling unit shall be considered a zone and
  provided with at least one temperature control
  device
• 503.3.2.3 Heat Pump Auxiliary Heat
• Heat pumps with supplementary electric resistance
  heat shall have controls to prevent heater
  operation when the load can be met by the heat
  pump alone (except defrost cycles)
• 503.3.2.4 Humidistat
• Must be capable of being set to prevent the use
  of fossil fuels or electricity to reduce relative
  humidity below 60 or increase relative humidity
  above 30

Section 503.3.2
67
Thermostatic Control Capabilities

• Section 503.3.2.2
• Heating only 55F or lower
• Cooling only 85F or higher
• Both heating and cooling must be capable of a 5
  deadband
• Exceptions
• Special occupancy/use as approved by the building
  official
• Thermostats that require manual changeover
  between heating and cooling

Section 503.3.2.2
68
HVAC Piping Insulation

• Piping Insulation
• Table 503.3.3.1
• Exceptions
• Factory installed piping within HVAC equipment
• Piping that conveys fluids between 55 and 105 F
• Piping which conveys fluids which have not been
  heated or cooled by through the use of fossil
  fuels or electricity

Section 503.3.3.1
69
Pipe Insulation (contd)
Distribution System - Minimum Pipe
Insulation Table 503.3.3.1
Section 503.3.3.1
70
Duct and Plenum Insulation

• Table 503.3.3.3 or where applicable ducts and
  plenums operate at static pressures gt 2 in. w.g.
• Exceptions
• Factory installed plenums, casings or ductwork
  that is part of the HVAC equipment
• Ducts within the conditioned space that they
  serve

Section 503.3.3.3
71
Duct Insulation
Table 503.3.3.3 Minimum Duct Insulation (revised
2001/2003)
Section 503.3.3.3
72
Duct Construction

• High- and medium-pressure duct systems (static
  pressure gt 2 in. w.g.) to be insulated and sealed
• If static pressure gt 3 in. w.g.
• Shall be leak tested in accordance with Section
  803.3.6
• Pressure classifications noted on construction
  documents
• Low-pressure duct systems (static pressure ? 2
  in. w.g.)
• All longitudinal and transverse joints, seams and
  connections shall be securely fastened and sealed
  with welds, gaskets, mastics (adhesives),
  mastics-plus-embedded-fabric systems or tapes
• Exceptions
• Continuously welded or locking longitudinal
  joints and seams operating at static pressures lt
  2inches w.g.

Section 503.3.3.4
73
Duct Sealing

• Seal and securely fasten all joints, longitudinal
  and transverse seams and connections with
• welds
• gaskets
• mastics
• mastic-plus-embedded fabric systems
• tapes
• Unlisted duct tape is not permitted as a sealant
  on any metal ducts

Section 503.3.3.4.3
74
Duct Sealing
Section 503.3.3.4.3
75
Distribution Systems (contd)

• 503.3.3.5 Mechanical Ventilation
• Systems shall be equipped with a readily
  accessible shutoff or volume damper and shutoff
• Automatic or gravity dampers shall be used for
  outdoor intakes and exhausts
• 503.3.3.6 Transport energy
• A measure of proper duct design
• Air transport factor lt 5.5
• 503.3.3.7 Balancing
• HVAC systems shall provide a means for balancing
  (i.e. dampers, temperature or pressure test
  connections, balancing valves, etc.)

Section 503.3.3
76
Service Hot Water Outline
504.1 Scope 504.2 Water Heaters, Storage Tanks
Boilers 504.2.1 Performance Efficiency 504.2.2
Combination Systems 504.3 Swimming Pools 504.3.1
On-off Switch 504.3.2 Pool Covers 504.3.3 Time
Clocks 504.4 Hot Water System Controls 504.5 Pipe
Insulation 504.6 Conservation of Hot Water 504.7
Heat Traps
Section 504
77
Service Water Heating (contd)

• Summary of requirements
• Heat traps to reduce standby losses
• Pipe insulation to reduce distribution and
  standby losses
• Circulation loop temperature controls to reduce
  distribution losses

Section 504
78
Heat Traps

• Required on noncirculating hot water systems

Section 504.7
79
Auto-Circulating Systems

• Auto-circulating systems
• Insulated to levels in Table 504.5
• Exception
• Piping insulation is not required when the heat
  loss, without insulation, does not increase
  energy use

Table 504.5 Minimum Pipe Insulation (Thickness in
Inches)
Section 504.4