Residential Building Energy Standards (RBES) and Commercial Building Energy Standards (CBES) Updates Better Buildings by Design Conference - February 10, 2011 Navigant Consulting, Inc. (Consultants to Vermont DPS)
Mar 29, 2015
Residential Building Energy Standards (RBES)
and Commercial Building
Energy Standards (CBES) Updates
Better Buildings by Design Conference - February 10,
2011Navigant Consulting, Inc. (Consultants to Vermont
DPS)
Efficiency Vermont is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.
This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.
Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
Learning Objectives
At the end of this program, participants will be able to:
Gain a better understanding of the current VT residential and commercial energy codes
Understand challenges and issues related to implementation and enforcement of the energy code
Understand the overall process involved in current and future Vermont energy code updates
Course EvaluationsIn order to maintain high-quality learning experiences,
please access the evaluation for this course by logging into CES Discovery and clicking on the Course
Evaluation link on the left side of the page.
5
Agenda
• Background and legislative history—Stu Slote
• Residential Building Energy Standards (RBES)—Lee Wood
• Q & A
• Commercial Building Energy Standards (CBES)—Tim Guiterman
• Q & A
6
Code Update Process•Last Update: 2003 VT RBES
•ARRA Requirements: 2009 IECC
•May 27, 2009 - legislature adopted Act 45
•Stakeholder meetings held to gather feedback
•Advisory Committee meetings
•DPS filed rule with ICAR (Interagency Committee on Administrative Rules)
•DPS held public hearing
•LCAR to conduct hearing and vote on rule
•Rule to be adopted 15 days after filed
•RBES handbook update
RBES Update Process
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CBES Update Process
• Last Update: 2005 VT CBES
• ARRA Requirements: 2009 IECC or ASHRAE 90.1-2007
• Technical Advisory Panel (TAP)—Meetings in June and July of 2010—Highlighted areas for improvement—Included changes from current 2012 IECC /
ASHRAE 90.1-2010 update processes
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CBES Update Process
Overall direction for CBES Update• Meet minimum 2009 IECC / ASHRAE 90.1-2007
• Add VT-specific amendments and improvements
• Consider substantial changes to create 2012 IECC / ASHRAE 90.1-2010
• New VT CBES codebook (VT-specific version of IECC)
• Continue to maintain reference to ASHRAE 90.1 standard and allow that as approved compliance path
• Public hearing on proposed rule held Jan 27
• Public comment period ended February 4
• LCAR to conduct hearing and vote on rule
• Rule to be adopted 15 days after filed
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CBES Update Process
Where are Commercial Codes Headed?
Source: NEEP Building Energy Codes Policy 3/1/2009
RESIDENTIAL BUILDING ENERGY STANDARDS
(RBES)
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1 Section 1: RBES Administration
2 Section 2: Major Changes to RBES
Table of Contents
12
Administration and Enforcement 2003 2011
Self certification X X
Certificate of compliance X X
Filing process to remain unchanged
Section 1 » RBES Administration
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Applicability 2003 2011
New single family homes X X
New multifamily homes X X
Change in occupancy or use X X
Change in space conditioning X
Additions, alterations, renovations, or repairs
X
Section 1 » RBES Administration
14
Additions, alterations, renovations, or repairs
Conform as with new construction
Unaltered portions do not need to comply
Additions can comply alone or in combination with existing building
Section 1 » RBES Administration
Exceptions
Storm windows over existing fenestration
Glass only replacements
Exposed cavities already filled with insulation
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Exemptions 2003 2011
Very low energy use buildings X X
Unconditioned buildings X X
Existing Buildings X X
Historic Buildings X X
Owner Built Homes X X
Hunting Camps X X
Section 1 » RBES Administration
RBES
Compliance Paths
Prescriptive Approach
Mandatory Requirements
Start
Performance Approach
Either
R-Values Table
402.1.1
U-Factor Alternative
Table 402.1.3
Total UA Alternative
402.1.4
REScheck
HERS Rating
Section 1 » RBES Administration
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1 Section 1: RBES Administration
2 Section 2: Major Changes to RBES
Table of Contents
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Mandatory Requirements 2003 2011
Piping insulation X XVapor Retarder X XMechanical ventilation X XCombustion safety X XAir Sealing and verification XLighting XFenestration U-factors XProgrammable thermostat XDuct sealing and testing XEquipment sizing XSnow melt system controls XPools, hot tubs and spas X
Section 2 » Major Changes to RBES
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Building Envelope
ComponentR-Value Exemptions
2003 2011 1. R-38 if uncompressed
2. 500 ft2 for vaulted ceilings
Ceiling 38 49
Source: US DOE
Section 2 » Major Changes to RBES
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Building Envelope
ComponentR-Value Notes
2003 2011 R-20 cavityorR-13 cavity + R-5
sheathing
Wood Frame Wall 13 20 or
13 + 5
Source: DOE
Section 2 » Major Changes to RBES
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Building Envelope
ComponentR-Value Notes
2003 2011 R-15 continuousorR-20 cavity
Basement or Crawlspace
Wall13 15 / 20
Source: Building Science Corp
Section 2 » Major Changes to RBES
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Building Envelope
ComponentR-Value Notes
2003 2011 Heated slabs must have R-15 beneath entire slabSlab Edge 10, 4ft 15, 4ft
Source: Building Energy Codes Program
Section 2 » Major Changes to RBES
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Component Window U-Factor Skylight U-Factor
2003 2011 2003 2011
Fenestration 0.40 0.32 NR 0.55
Fenestration
Notes1. Area-weighted averages2. 15 ft2 of glazing exempt3. One opaque door exempt
Section 2 » Major Changes to RBES
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Component RBES 2003 RBES 2011
Air Leakage No testing requirements
1.Test: < 5 ACH@50 2.Visual Inspection
Checklist
Air Leakage
Source: RBES Handbook
Section 2 » Major Changes to RBES
25
Component RBES 2003 RBES 2011
Spillage Testing
No testing requirements
Must establish draft without spillage within two minutes
Spillage Testing
Source: Saturn Resource Management
Section 2 » Major Changes to RBES
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Component RBES 2003 RBES 2011
Programmable Thermostat No requirement MANDATORY
Temperature Controls
Component RBES 2003 RBES 2011
Lighting No requirement50% of lamps in permanent fixtures high-efficacy
Lighting
Section 2 » Major Changes to RBES
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COMPONENT RBES 2003 RBES 2011
Duct Sealing No verification requirement
Must be verified by:*1. Post-construction test:
Leakage to outdoors < 6 cfm per 100 ft2 of conditioned floor area (CFA)
2. Rough-in test: Total leakage < 3 cfm per 100 ft2 of conditioned floor area (CFA)
Duct Insulation
R-8 Same R-value as surrounding surfaces*
Ducts
* Unless located within conditioned space
Section 2 » Major Changes to RBES
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Mechanical Ventilation
COMPONENT 2003 2011
Balanced systems X X
Exhaust-only systems X X
Supply-only systems X
Section 2 » Major Changes to RBES
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COMPONENT RBES 2003 RBES 2011
Piping Insulation Varied R-3
Domestic Hot Water
Source: Saturn Resource Management
Section 2 » Major Changes to RBES
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COMPONENT RBES 2003 RBES 2011
Snow Melt Systems
No requirements Mandatory automatic controls
Pool HeatersMandatory on / off switch
Mandatory on / off switch
Pool Covers (heated pools)
Pool cover requiredPool cover requiredR-12 minimum for hot tubs and spas
Other Requirements
Section 2 » Major Changes to RBES
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Component 2003 2011
Basement Wall U-Factor 0.10 0.05
Floor U-Factor 0.033 0.026
Ceiling U-Factor 0.026 0.020
Fenestration U-Factor 0.40 0.30
Log Homes
Log walls must comply with ICC400 with average minimum wall thickness of 5” or greater, and have heating system AFUE of 90% (gas) or 85% (oil). Boilers must have outdoor temperature reset or thermal purge control.
Section 2 » Major Changes to RBES
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Questions?
COMMERCIAL BUILDING ENERGY STANDARDS
(CBES)
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CBES Presentation » Overview
• Key Items
• Details on code update—Administration—Definitions—General Requirements—Envelope—Mechanical Systems—Service Water Heating—Electrical Power and Lighting
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CBES Presentation » Key Items
• 2012 IECC and ASHRAE 90.1-2010 recently finalized in Fall 2010
• Significant changes to 2012 IECC initiated by joint proposals—Department of Energy (DOE)—New Buildings Institute (NBI)—American Institute of Architects (AIA)
• Presentation Format
CHAPTER 1ADMINISTRATION
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Introduction to Compliance Process
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Must the Project Comply with the
IECC?
Comply with the Envelope
Requirements
Comply with the Mechanical/SWH
Requirements
Comply with the Power & Lighting
Requirements
Section 502 90.1 Section 5Sections 503 and
50490.1 Section 6 Section 505 90.1 Section 9
Document Compliance with
the IECC
Plan Review
Inspection
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Chapter 1 » Administration
101.2 Scope—Code does not apply to farm structures or
process applications (equipment / systems)
101.5 ComplianceExempt Buildings1.Low energy buildings (<3.4 Btu/h*ft2 for space
conditioning)2.Unconditioned buildings3.Inflatable buildings
Context: Re-organizes exemptions from 2005 CBES. Inflatable & Unconditioned buildings added.
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101.4.3 : Alterations, Additions, Renovations and Repairs—If energy use is not increased, following
need not comply Re-roofing where neither sheathing nor insulation is exposed
Alterations that replace < 50% of luminaires
Alterations that replace only bulb and ballast
Context: New in 2009 IECC
Chapter 1 » Administration
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103: Construction Documents1. Added: Additional information required on construction
documentsa. Design ambient temperatures; interior temps. for heating
/ cooling modes; relative humidity setpoints; ventilation rates
2. Added: Additional info. required on mechanical equipment schedules
a. Equipment efficiencies; Fan and pump nameplate motor / brake horsepower; Hydronic system (if applicable) supply / return water design temps. for boilers and all terminal devices (e.g. baseboards, unit ventilators, etc); Steam system (if applicable) design pressure for boilers and all terminal devices
Context: Rarely included, but useful information for code review, commissioning, future energy audits, etc.
Chapter 1 » Administration
CHAPTER 2DEFINITIONS
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42
Chapter 2 » Definitions
Context: Definitions complement new/revised sections of code. Many are new in 2009 IECC and some from 2012 IECC.
CHAPTER 3GENERAL
REQUIREMENTS
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Chapter 3 » General Requirements
301: Design Conditions— 2005 CBES: broad allowance for adjustments
— 2011 CBES: adjustments for1. Winter heating design temperatures for projects
located at either:a. Elevation of 1,500 feet or higherb. Caledonia, Essex or Orleans counties
2. As approved by code official or other authority having jurisdiction
Context: Improve language from 2005 VT CBES which allowed adjustments for “local design conditions”
SECTION 502BUILDING ENVELOPE
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Building Envelope
502.2.1: Roof Assembly—Added: Requirement to insulate skylight
and mechanical curbs to at least R-5
Context: Skylight curbs included in proposal for 2012 IECC. Mechanical curb recommended by TAP.
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Table 502.2 (1) Envelope Tables1. Envelope R-Values/U-Factors only for Vermont
Climate Zone (CZ) 6
2. Added additional metal building description and U-factor reference tables
3. Maximum Vertical fenestration area is 40% of above-grade wall area, same as 2009 IECC. 2005 CBES was 50% maximum
Thermal Blocks
Insulation Draped Over Purlin
Insulation Parallel to Purlin
Picture from NAIMAThermal Blocks
Insulation Draped Over Purlin
Insulation Parallel to Purlin
Picture from NAIMA
Building Envelope
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Building Envelope - Opaque Assemblies
Roofs 2005 CBES
2009 IECC /
90.1-2007
2011 CBES
Roof: Insulation entirely above deck
R - 24 ci
U - 0.040
R - 20 ci
U - 0.048
R - 30 ci
U - 0.032
Metal Buildings
R - 19 + R - 10 or R - 30
U - 0.051
R - 13 + R - 19
U - 0.049
R - 11 + R - 13ci
U - 0.045
Steel Joist
R - 30 + R - 5ci (with R - 5 thermal
blocks)U - 0.027
N / A N / A
Attic and other
R - 38U - 0.27
R - 38U - 0.27
R - 38U - 0.027
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Walls-Above Grade
2005 CBES
2009 IECC /
90.1-2007
2011 CBES
Mass
R - 9.5 ci
U - 0.104
R - 13.3 ci
U - 0.080
R - 13.3 ci
U - 0.080
Metal building
R - 19 or R - 6 + R - 13
U - 0.070
R - 13 + R - 5.6 ci
U - 0.069
R - 11 + R - 6.5 ci
U - 0.054
Metal-framed
R - 13 + R - 7.5 ci
U - 0.064
R - 13 + R - 7.5 ci
U - 0.064
R - 13 + R - 7.5 ci
U - 0.064
Wood-framed
and other
R - 19 or R - 12 ci or R - 13 + R -
3.8 ci
U - 0.064
R - 13 + R - 7.5 ci
U - 0.051
R - 13 + R - 7.5 ci or
R - 20 + R - 3.8 ci or
R - 23U - 0.051
Building Envelope - Opaque Assemblies
Note: VT was already ahead of 2009 IECC. Recommendation to maintain current 2005 VT CBES values.
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Walls-Below Grade
2005 CBES
2009 IECC /
90.1-2007
2011 CBES
Below Grade Wall
R - 10 ci
C - 0.092
R - 7.5 ci
C - 0.119
R - 10 ci
C - 0.092
Building Envelope - Opaque Assemblies
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Floors 2005 CBES
2009 IECC /
90.1-2007
2011 CBES
Mass
R - 10ci
U - 0.074
R - 12.5 ci
U - 0.064
R - 12.5 ci
U - 0.064
Joist / Framing-Metal*
R - 30
U - 0.038 R - 30
U - 0.033
R - 30
U - 0.033
Joist / Framing-Wood and
Other*
R - 30
U - 0.033
R - 30
U - 0.033
*Note: Final version will consolidate 2 categories into one, per 2009 IECC
Building Envelope - Opaque Assemblies
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Slab-on-Grade Floors*
2005 CBES
2009 IECC/90.1-2007
2011 CBES
Unheated
R - 10 for 48 inches
F - 0.64
R - 10 for 24 inches below
F - 0.55
R - 10 for 48 inches
F - 0.48**
Heated
R - 10 for entire slab (under slab
and perimeter)
F - 0.55
R - 15 for 24 inches below
F - 0.86
R - 10 for entire slab (under slab and perimeter)
F - 0.55* Insulation shall be placed on the exterior of the foundation
** Change to F-Value from 2005 CBES to reflect vertical installation (Or downward to bottom of slab and then horizontally for total distance shown in table)
Building Envelope - Opaque Assemblies
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Opaque Doors
2005 CBES
2009 IECC/90.1-2007
2011 CBES
Swinging U - 0.50 U - 0.70 U - 0.37
Roll-Up or sliding R - 10 U - 0.50 U - 0.50
Upward-Acting or Sectional N / A N / A R - 10
Note:• 2009 IECC / ASHRAE 90.1 only provides U-Factors• Upward-Acting or Sectional is new and unique to VT code
Building Envelope - Opaque Assemblies
Note:
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Building Envelope - FenestrationCategory 2005 CBES 2009 IECC 2011 CBES
Vertical Fenestration (Maximum %) 50% 40% 40%
Framing Materials other than Metal with or
without Metal Reinforcement or
Cladding U-0.35 U-0.35 U-0.35Metal framing with or without Thermal Break
Curtain Wall/Storefront U-0.45 U-0.45 U-0.42Entrance Door U-0.80 U-0.80 U-0.80
All Other U-0.50 U-0.55 U-0.50SHGC-All Frame Types
PF < 0.25 U-0.40 U-0.40 U-0.400.25 < PF < 0.5 U-0.55 NR U-0.55
PF >= 0.5 NR NR NRSkylights (Maximum %) 5% 3% 3%
Skylights, Glass U-0.60 U-0.60 U-0.50 SHGC-0.40 SHGC-0.40 SHGC-0.40
Skylights, Plastic U-0.60Plastic Not Specified
SHGC-0.62Plastic Not Specified
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502.4. Air Leakage— 2005 CBES and 2009 IECC: broad language— 2011 CBES: Mandatory continuous air barrier
Air barrier compliance options– Option 1: Materials– Option 2: Assemblies– Option 3: Building Test (0.31 cfm/ft2 of shell area @ 50
Pa) Air Barrier penetrations-explicit language on air sealing Fenestration air leakage table
Context
• Substantial part of joint DOE/NBI/AIA proposal to 2012 IECC
• Originally adapted from MA building code, so “field-tested” and regionally appropriate
Building Envelope
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502.4.7 Vestibules1. Revised to reflect changes in proposed 2012 IECC
a. Utilizes new definition of “Building Entrance”2. VT - specific:
a. If vestibule is tempered, max temperature setting of 55° F; Cooling prohibited
b. If tempered, shall be constructed according to envelope provisions
c. If tempered, thermostat shall be programmable and inaccessible to public
Context1. Improved language from model IECC codes2. TAP recommended changes due to extensive issues with
energy use due to heating and cooling of vestibules
Building Envelope
SECTION 503BUILDING MECHANICAL
SYSTEMS
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Building Mechanical Systems
Overview of changes due to 2009 IECC
• Revises equipment efficiency tables for water-chilling packages; minimum equipment efficiencies changed
• Requires snow melt control
• Requires demand control ventilation (DCV) for certain spaces
• Removes exception for energy recovery ventilation for lab fume hood systems ≤ 15,000 cfm
• Lowers the system capacity for economizer requirement for most climate zones
• Introduces fan power limitations
• Introduces supply air temperature reset controls for multiple-zone systems
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1. 503.1.2 Electric Resistance Space Heating— Prohibition on electric resistance space heating
a. Carried over from 2005 VT CBES
2. 503.2.5 Ventilationa. References ASHRAE 62.1-2007 rather than IMCb. Added language emphasizing ventilation rates to be
based on expected occupancy levels versus default IMC / ASHRAE 62.1 rates
Context1. Important prohibition on electric resistance heating
that has worked for VT2. Prevents designers from using worst-case
ventilation rates when better information is available
Building Mechanical Systems
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503.2.5.2: Demand Controlled Ventilation
• 2005 CBES had no DCV requirement
• 2011 CBES (2009 IECC): DCV must be provided for each zone with spaces > 500 ft² and average occupant load > 40 people / 1000 ft² of floor area where HVAC system has: An air-side economizer, or Automatic modulating control of outdoor air damper, or Design outdoor airflow > 3,000 cfm
Demand control ventilation (DCV): ventilation system capability that provides for automatic reduction of outdoor air intake below design rates when actual occupancy of spaces served by system is less than design occupancy
Building Mechanical Systems
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503.2.7: Duct and Plenum Insulation and Sealing
• 2005 CBES (Also 2009 IECC): Minimum R-5 (unconditioned space) and R-8 (outside building)
• 2011 CBES : “All supply and return ducts located in unconditioned spaces shall be insulated to meet same R-value requirement that applies to immediately proximal surfaces.”
Context: Altered to align with RBES
• Public comments raised to address this language—Clarify—Feasibility
Building Mechanical Systems
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503.2.10: Systems Performance Verification and Completion 1. Buildings ≥ 50,000 SF2. Requirements for independent, third-party
commissioning agents to perform basic functional testing to verify efficient “as-designed” operation of systems specified in other parts of code, limited to:
a. Economizersb. VAV fan controlc. Part-load hydronic controls
3. Prescriptive testing requirements
FAIL
Building Mechanical Systems
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503.2.10 Systems Performance Verification and Completion (Continued)
Context1. 2012 IECC dedicates separate chapter to commissioning
(Cx) requirements2. Cx for buildings > 50K ft2 as starting point for code
requirements3. Current proposal provides testing ground for future Cx
requirements in VT, utilizing only large buildings4. Feedback from use of 2012 IECC and VT requirements will
be helpful for next update of VT code5. Performance verification should ensure systems comply with
code intent and operating at maximum energy efficiency6. Performance verification improves building performance,
hopefully reduces contractor call-backs, issues
Building Mechanical Systems
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Revised 503.3.1 Economizers and 503.4.1 Economizers (Complex HVAC Systems)1. Economizers required on all systems ≥ 54,000 Btu / h (2005
CBES ≥ 65,000 Btu/h)2. Defined allowable economizer sequences to align w/ASHRAE 90.1-
20073. Clarified section 503.4.1 using improved language from 2012 IECC
proposalsa. Design Capacityb. Maximum Pressure Dropc. Integrated Economizer Control
Context1. Matches 2009 IECC capacity threshold2. Need to clarify 2005 VT CBES and Economizer sections in 2009
IECC vague3. National IECC code also using these changes to align w/ ASHRAE
90.1
Building Mechanical Systems
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503.4.2 VAV Fan Control / 503.4.3 Hydronic Systems Controls / 503.4.3.6
1. Added: 503.4.2.1 Static Pressure Sensor Location language
2. Revised: 503.4.3.4 Hydronic variable flow systems language
3. Added: 503.4.3.6 Chilled and Hot Water Temperature Controls
Context1. Language not in 2009 IECC but existed in
ASHRAE 90.1-20072. Language taken from 90.1-20073. Language taken from 90.1-2007
Building Mechanical Systems
SECTION 504SERVICE WATER
HEATING
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Service Water Heating
504.1.1 Electrical Water Heating LimitationAdded: Electric service water heating units shall be
limited to a maximum of 5 kW total power input
Context: Carried over from 2005 VT CBESES
Yes, that is David Hasselhoff
SECTION 505ELECTRICAL POWER AND
LIGHTING SYSTEMS
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Major changes to electrical power / lighting due to 2009 IECC
• Adds high-efficacy lighting requirement for dwelling units
• Requires separate controls for daylight zones
• Allows for use of photocell in tandem with other controls on certain exterior lighting applications
• Adds exempted lighting applications that can be excluded from total connected interior lighting power calculations
• Revises additional lighting power allowance calculations for retail areas
• Creates four exterior lighting zones based on lighting need
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Electrical Power and Lighting
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Interior Lighting Power Allowances1. Building Area Method and Space by space Method
included2. LPD values taken from proposed 2012 IECC values
Context1. 2005 VT CBES contained both methods but 2009
IECC still only used Building Area Methoda. 2012 IECC will have both methods
2. 2005 VT CBES values identical to 2009 IECCa. 2012 IECC values include revised categories,
higher efficiency for certain categories, and scaled back values for others
b. 2011 VT CBES will be aligned with 2012 IECC and ASHRAE 90.1-2010
Electrical Power and Lighting
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• Interior Lighting Power Allowances— Changes to Building Area Method Spaces
— All others unchanged from 2005 CBES— Some changes in space-by-space types:
Revised categories, higher efficiency for certain categories, and scaled back values for others
2005 CBES
2009 IECC 2011 CBES
Office 1.0 1.0 0.9
Retail 1.5 1.5 1.4
Fire Station 1.0 1.0 0.8
Warehouse 0.8 0.8 0.6
Electrical Power and Lighting
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Motors and Transformers1. Added NEMA efficiency tables for motors2. Added NEMA efficiency tables for transformers
Context1. VT CBES included these. Maintained in 2011 VT
CBES. Motor tables are included in ASHRAE 90.1-2007.
2. VT CBES included these. Maintained in 2011 VT CBES.
Electrical Power and Lighting
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Questions?