Upload
merilyn-reed
View
215
Download
1
Tags:
Embed Size (px)
Citation preview
IRC CHAPTER 11 AND HERSRESIDENTIAL ENERGY
Kelly Parker, P.E.Oklahoma Building Summit
August 26, 2015
IRC Chapter 11 and HERS
HERS: Home Energy Rating System
IRC Chapter 11 and HERS
RESNET
The RESNET vision: “RESNET’s vision is of a world that encourages and rewards minimum building energy use through independent, performance-based building certification.”
RESNET
The RESNET mission: “RESNET’s mission is to ensure the success of the building energy performance certification industry, set the standards of quality and increase the opportunity for ownership of high performance buildings.”
Who Recognizes RESNET’s Standards
Builders (for the HERS Rating)Contractors (the emerging retrofit market)States and municipalities for code complianceFederal government agencies
IRS: 2005 EPACT new housing tax credit Environmental Protection Agency (EPA): the
ENERGY STAR for Homes program (Version 3) Department of Energy (DOE): Building America
and National Builders Challenge programs
2009 International Residential Code
Chapter 11
• Approved software is used to develop a Index.
• REM/Rate • Energy Gauge • Others
IRC CHAPTER 11 AND HERS
HERS inputs into REM/Rate:1. General building inputs (sf, vol, # of floors, bedrooms)
2. Foundation wall properties
3. Slab floor properties (sf, insulation, exposed perimeter)
4. Floors over unconditioned space.
5. Rim and band properties (sf, R-value)
6. Above grade wall properties (sf, type)
7. Windows and glass doors (sf, U-factor, SHGC, shading)
8. Door properties
9. Ceiling properties (sf, type, R-value)
Chapter 11 and HERS
HERS inputs into REM/Rate:10.Mechanical equipment properties (Btuh, efficiency)
11. Duct system summary (sf, R-value, location, leakage)
12.Blower door test (leakage)
13.Mechanical ventilation
14.Appliances and lighting summary
IRC 2009 RESIDENTIAL ENERGY
• New Codes are here and adopted statewide July, 2011.
• The 2009 IRC addresses issues that have been building problems in the past.
• Several problem areas that have been around for years will now have solutions.
Adopted Building Codes
Code Adopted Effective Date of Adoption Modifications to the code
International Residential Code ®, 2009 Edition (IRC®, 2009) July 15, 2011 Click Here for modifications to
the code adopted by reference
Adopted Building Codes
Code Adopted Effective Date of Adoption Modifications to the code
International Residential Code ®, 2009 Edition (IRC®, 2009) July 15, 2011 Click Here for modifications to
the code adopted by reference
Oklahoma Uniform Building Code Commission
www.ok.gov.oubcc/
Chapter 11, Energy Efficiency
N1101.1 Scope
This chapter is for regulating the design and construction of buildings to improve the energy efficiency of those structures.
Chapter 11, Energy Efficiency
N1101.2 Compliance
• Demonstrated by either meeting the requirements of this chapter or the 2009 International Energy Conservation Code.
• Requirements are climate specific according to Figures N1101.2 and Table N1101.2.
Chapter 11, Energy Efficiency
N1101.2.1 and Table N1101.2
Climate Zones, Moisture Regimes, and Warm-Humid Designations (clarification)
• Places all the above info into one table.
• Provides county designations for clarity and usability.
• Warm humid counties are now indicated with an asterisk.
All counties in Oklahoma are Climate Zone 3A except for Beaver, Cimarron, and Texas located in the panhandle
which are 4B
Chapter 11, Energy Efficiency
By accepting State Energy Program funding and submitting letters assuring the
Department of Energy that their states would comply with the terms of Section 410, all 50
states have committed to do three things:
1. Adopt a residential building energy code that meets or exceeds the 2009
International Energy Conservation Code (IECC);¹
2. Adopt a commercial building energy code that meets or exceeds the
ANSI/American Society of Heating, Refrigerating and Air-Conditioning Engineers
(ASHRAE)/IESNA Standard 90.1-2007; and
3. Develop and implement a plan, including active training and enforcement
provisions, to achieve 90 percent compliance with the target codes by 2017,
including measuring current compliance each year.
¹ U.S. DOE has determined that the 2009 International Residential Code (IRC) does not
meet the energy provisions of the 2009 International Energy Conservation Code (IECC).
Chapter 11, Energy Efficiency
N1101.3 Identification
The code is to identify materials, systems and equipment that allow for the determination of compliance to meet the energy efficiency requirements of this chapter.
Chapter 11, Energy Efficiency
All counties are in zone 3AExcept Beaver, Cimarron, and Texas, which are in zone 4B.
Chapter 11, Energy Efficiency
Chapter 11, Energy Efficiency
N1101.4 Building Thermal Envelope Insulation
• All installed insulation ≥12” must have the R-value marked or a certificate must be provided.
• For sprayed or blown insulation (fiberglass or cellulose), a certificate must list:– Initial installed thickness– Settled thickness– Settled R-value – Installed density– Coverage area– Number of bags installed
Chapter 11, Energy Efficiency
N1101.4 Building Thermal Envelope Insulation (continued)
For sprayed polyurethane
foam:• Installed thickness• R-value of installation
Sticker shall be signed, dated and posted in a “conspicuous location on the job site.”
Chapter 11, Energy Efficiency
N1101.4 Blown or Sprayed Roof/Ceiling Insulation
• Markers installed 1 for every 300sf with numbers at least 1” tall to help determine the depth of the installed insulation.
• Stickers must face the attic access opening.
Chapter 11, Energy Efficiency
N1101.5 Fenestration Product Rating
• For U-factors (windows, doors and skylights) and solar heat gain coefficient (SHGC) (glazed fenestration) must have a label on each product or assigned a default value from Tables N1101.5(1)-N1101.5(3).
• Must be accredited by an independent lab and labeled and certified by the manufacturer.
N1101.8 Above Code Programs
• National, state, or local energy efficiency programs may be used, at the building official or other jurisdiction’s discretion as conforming to the energy code.
• REM/Rate and HERS Index
• REScheck
Chapter 11, Energy Efficiency
Chapter 11, Energy Efficiency
N1101.9 Permanent Energy Certificate (modification)
• Certificate shall not cover or obstruct required labels on an electrical distribution panel. (Sticker not required in Oklahoma)
• An efficiency shall not be listed for gas-fired unvented room heaters, electric furnaces, or electric baseboard heaters.
Chapter 11, Energy Efficiency
Coming to ALL Houses
Example
Chapter 11, Energy Efficiency
N1102.1 Insulation and Fenestration Criteria
The building envelope shall meet the requirements found in Table N1102.1 according to climate zones found in Table N1101.2.
Chapter 11, Energy Efficiency
Chapter 11, Energy Efficiency
N1102.1.1 R-value Computation
• Shall be the sum of the wall insulation R-value plus the exterior sheathing. No other components are included.
• The settled R-value shall be used for blown insulation.
Chapter 11, Energy Efficiency
N1102.1.2 U-factor Alternative
1. U-factor from Table N1102.1.2 shall be allowed instead of the R-values from Table N1102.1.
2. Comment: U-factor is the inverse of the R-value. Ceiling U-factor of 0.033 is equal to an R-value of 30.
U=1/R
Chapter 11, Energy Efficiency
N1102.1.3 Total UA Alternative
“If the total building thermal envelope UA (sum of the U-factor times assembly area) is less than or equal to the total UA resulting from using the U-factors in Table N1102.1.2, (multiplied by the same assembly area as in the proposed building), the building shall be considered in compliance with Table N1102.1.”
Chapter 11, Energy Efficiency
N1102.2.1 Ceilings with Attic Spaces
Section requires increased R-values over the exterior wall top plates:
• R-30 where R-38 is called for in attic.• R-38 where R-49 is called for in attic.• Does not address R-30 insulation requirement. • The stated insulation must be uncompressed.
Comment: An R-30 batt in a 6” cavity is approximately equal to an R-21.
Chapter 11, Energy Efficiency
N1102.2.2 Ceilings without Attic Spaces
Where >R-30 is required for a ceiling but space does not allow for it, R-30 shall be allowed for up to 500sf.
Chapter 11, Energy Efficiency
N1102.2 Ceiling and Access Hatch Insulation Requirements (clarification)
• Access doors to unconditioned space will be weatherstripped and insulated to same R-value as the ceiling.
• Insulation baffle installed at edges to prevent spilling into the living space and maintain the installed R-value.
Chapter 11, Energy Efficiency
Table N1102.2.5 Steel Framed Wall Insulation (modification)
Contains an option for steel framed wall without cavity insulation for Zones 1 thru 4. Apply continuous insulation R-10 to outside (equivalent of wood frame R-13).
Chapter 11, Energy Efficiency
N1102.2.6 Floors• Floor insulation must be placed in permanent contact
with the subfloor.• Comment: Staples are not permanent; gravity eventually
wins. Requires tension wires or equivalent.
Chapter 11, Energy Efficiency
N1102.2.7 Basement Walls
• Basement walls for conditioned space shall be insulated from the grade plane to either 10 feet below or to the basement floor, whichever is less.
• For climate zone 3, requires either an R-5 on the exterior or R-13 on the interior.
• No wall insulation required if the floor above the basement is insulated.
Chapter 11, Energy Efficiency
N1102.2.8 Slab-on-grade Floors
• No insulation required for Climate Zone 3.• Comment: Slab insulation can be used for the
Federal Tax Credit, which expired December 31. We are hoping it will be renewed.
• Comment: Some builders are achieving a HERS Index of 70 (30% more efficient than a house built to the 2004 IECC) and less to obtain the state tax credit.
Chapter 11, Energy Efficiency
N1102.2.9 Crawl Space Walls
• Nothing required if floor is insulated and crawl is vented.
• If unvented, crawl space wall insulation must be permanently attached from the floor to the finished Grade level and then vertically and/or horizontally an additional 24 inches.
• Exposed earth shall be covered with a Class I vapor retarder, overlapped 6” and joints sealed or taped and attached to the stem wall at a height of at least 6”.
Chapter 11, Energy Efficiency
N1102.2.11 Thermal Isolated Sunroom Insulation
• Ceiling insulation shall be R-19 for Climate Zones 1-4 and R-24 for Zones 5-8.
• Wall insulation shall be at least an R-13.
• New walls to meet current construction code requirements.
Chapter 11, Energy Efficiency
N1102.3.3 Glazed Fenestration Exemption
U-factor and SHGC requirements can be waived for up to 15sf of glass.
N1102.3.4 Opaque Door Exemption
For one opaque door up to 24sf can be exempted from the U-factor requirements.
Chapter 11, Energy Efficiency
N1102.3.6 Replacement Fenestration
Shall meet the requirements for U-factor and SHGC from Table N1102.1.
Chapter 11, Energy Efficiency
N1102.4.1 Sealing of the Building Thermal Envelope (clarification)1. Joints, seams and penetrations
2. Site-built windows, doors, and skylights
3. Openings between windows/doors and framing or jambs
4. Utility penetrations
5. Dropped ceilings or chases
6. Kneewalls
7. Walls and ceilings separating garage from conditioned space
8. Behind tubs and showers on exterior walls
9. Common walls between units
10. Attic access openings
11. Rim joist junction
12. Other sources of infiltration
Chapter 11, Energy Efficiency
N1102.4.2.1• Envelope leakage testing
option to 7 ACH at 50 Pa. Seven requirements for testing.
N1102.4.2.2• Visual inspection option
allowed by code official by third party independent from the insulation contractor following list in N1102.4.1.
Chapter 11, Energy Efficiency
N1102.4.5 Recessed Lighting (modification)
• Shall be IC rated.
• Shall be labeled as meeting ASTM E 283 for air leakage.
• Shall be sealed with caulk or a gasket between the housing and interior wall.
• New term: ICAT, Insulation Contact Air Tight
Chapter 11, Energy Efficiency
N1103.1.1 Programmable Thermostat
• Each dwelling unit shall have one thermostat capable of maintaining a daily schedule to maintain different temperature set points.
• Must be able to achieve temperatures from 55° to 85°.
• Not required in Oklahoma at this time. Update: July, 2015 new IRC??
Chapter 11, Energy Efficiency
N1103.1.2 Heat Pump Supplementary Heat
When supplementary electric resistance heat, must have controls preventing supplemental heat operation when the unit is capable of meeting the heating load.
Emergency Heating
Chapter 11, Energy Efficiency
N1103.2.1 Duct Insulation
Ducts in unconditioned space shall be R-8. All others shall be R-6.
Oklahoma Tax Credit: Supply and return ducts shall be insulated to a minimum of R-8
Chapter 11, Energy Efficiency
N1103.2.2 Duct Sealing (addition)
• Duct tightness shall be verified by either
– Post construction test, leakage to outside at 8 cfm per 100 sf or total leakage test at 12 cfm per 100 sf, both at 25 Pa.
– Rough-in test, total leakage at 6 cfm per 100 sf tested at 25 Pa.
(Visual inspection may be used instead of the rough-in test and post construction
test in Oklahoma.)
Chapter 11, Energy Efficiency
N1103.2.3 Building Cavities
Building framing cavities shall not be used as supply ducts
N1103.3 Mechanical System Piping Insulation
All mechanical system piping carrying fluids above 105°F or below 55°F must be insulated to at least an R-3.
Chapter 11, Energy Efficiency
N1103.4 Circulating Hot Water Systems
• All lines shall be insulated to at least an R-2.
• In addition, there must be a readily accessible manual switch for disengaging the system when not being used.
Chapter 11, Energy Efficiency
N1103.6 Equipment Sizing• “Heating and cooling equipment shall be sized as specified in
Section M1401.3.”• All buildings must have load calculations performed.
M1401.3 Sizing
HVAC system sized according to ACCA Manual S based on load calculations from ACCA Manual J (Version 8 is the latest version)
Comment: ACCA Manual S - Residential Heating and Cooling Equipment Selection
Comment: ACCA Manual J8 – Residential Load Calculation
Chapter 11, Energy Efficiency
N1103.8.1 Pool Heaters
• All pool heaters shall have a readily accessible on/off switch for turning the equipment off without adjusting the thermostat.
• No continuous burning pilot lights allowed.
Chapter 11, Energy Efficiency
N1103.8.2 Time Switches
Heaters and pumps must have time switches installed that can automatically control use of those components.
Chapter 11, Energy Efficiency
N1103.8.3 Pool Covers
• Heated pools shall have a vapor retardant pool cover on or at the water surface. Comment: removed from the code for Oklahoma.
• Pools heated above 90°F must have a cover with an R-value of at least 12. Comment: remains in the Oklahoma code.
Chapter 11, Energy Efficiency
N1104 Lighting Systems (addition)
• 50% of permanently installed lighting fixtures required to be CFLs or other high-efficacy lamps.
• Comment: Can or
recessed lighting are
exempt in Oklahoma.• Update, 2015 IRC??