Non-Residential HVAC Stakeholder Meeting #1 California Statewide - - PowerPoint PPT Presentation

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California Statewide Utility Codes and Standards Program

Non-Residential HVAC Stakeholder Meeting #1

Heschong Mahone Group, Inc. CTG Energetics Portland Energy Conservation, Inc. Taylor Engineering, LLC April 27, 2010

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Agenda

• 10:00–10:30

Introduction

• Overview of 2011 Title 24 Development
• Summary of stakeholder purpose and process
• 10:30–12:00

HVAC Controls And Economizing

12:00–12:30 Lunch

• 12:30–1:30

Outside Air Ventilation

• 1:30–2:00

Energy Recovery For High Minimum Outside Air Systems

• 2:00-3:00

HVAC Efficiency And Baseline

3:00-3:15 Break

• 3:15–3:45

Single Zone VAV

• 3:45–4:15

Reduce Reheat

• 4:15–4:30

Radiant Cooling

• 4:30-4:45

Water+space Heating

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

IOU Support for 2011 Title 24

• The California Investor Owned Utilities (IOUs) are

actively supporting the California Energy Commission (CEC) in developing the state’s building energy efficiency standard (Title 24).

• Their joint intent is to achieve significant energy savings

through the development of reasonable, responsible, and cost-effective code change proposals for the 2011 code update, and beyond.

• As part of the IOU effort, at the request of the CEC, we

are hosting stakeholder meetings to get industry input and feedback on our code change proposals.

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Code Change Activity

• 2011 T-24 Base Code
• 2011 Reach Standard
• Voluntary standards for local govts.
• Green Building Standard
• Toward Zero Net Energy goal
• 2014 T-24 base code
• Future reach standards

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Types of Code Change

• Mandatory Measure: The change would add or modify

a mandatory measure.

• Mandatory measures must be satisfied whether the prescriptive
• r performance method is used to show compliance.
• Prescriptive Requirement: The change would add or

modify a prescriptive requirement that must be met when using prescriptive compliance approach.

• When using performance compliance (computer modeling),

prescriptive requirements define a standard design (which sets the energy budget) and are not mandatory.

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Types of Code Change – Ctd.

• Compliance Option: The change would add or modify a

new measure to the list of existing compliance options for meeting the Standards using the performance approach.

• Modeling: The change would modify the calculation

procedures or assumptions used in making performance calculations.

• This change would not add a compliance option or a new

requirement, but would affect the way that trade-offs are made.

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Requirements for a Successful Code Change

• To be included in base code, a measure must:
• Be cost-effective according to the Time Dependent Valuation

(TDV) life-cycle costing methodology set out by the California Energy Commission

• Be possible to implement using equipment that is readily

available from multiple providers (or that is reasonably expected to be available following the code change).

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Schedule: CEC Key Dates

• Mar 2010 - Dec 2010
• CEC develop foundation
• IOUs:
• Conduct research, and cost effectiveness analysis
• Present results at stakeholder meetings
• Dec 2010
• IOUs finalize code change proposals for submittal to CEC
• Feb 2011
• CEC opens Rulemaking for Title 24, develop 45-day language
• June 15, 2011
• Title 24 Adoption date
• Jan. 1, 2013
• Title 24 Implementation date

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Stakeholder Meetings Purpose

• Publicize code change proposal
• Present to and solicit feedback from stakeholders on:
• Methodology
• Technology options
• Market status
• Draft code language
• Gather additional information from stakeholders on:
• Best practices
• Product/technology availability
• Market penetration data
• Cost data

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Stakeholder Meetings Process

• Minimum of three meetings:
• First: present scope
• Code change direction and possible options
• Methodology
• Second: present findings
• Results of data collection and analysis
• Cost effectiveness
• “Strawman” proposed code language
• Third/final: present proposed code language
• All meetings can be attended remotely

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Meeting Ground Rules

• For those attending by telephone/web
• Please mute your microphone, unless you want to speak
• Please do not place your phone on HOLD
• Ask questions/comment by “chat” or by voice
• We want to hear your concerns
• Opposing viewpoints are encouraged
• We are seeking information, not resolution
• Time is limited
• Raise your hand and be acknowledged by presenter
• Clearly state your name and affiliation prior to speaking
• Speak loudly for the people on the phone
• Minutes and presentation material will be distributed

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California Statewide Utility Codes and Standards Program

HVAC Controls & Economizing

Non-Residential HVAC Stakeholder Meeting #1

Matt Tyler Portland Energy Conservation, Inc. April 27, 2010

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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HVAC Controls & Economizing

• Summary of current code requirements
• Typical practice
• Summary of potential code change proposals
• Initial data/findings
• Potential code change proposals
• Planned data collection and analysis
• Specific stakeholder requests

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Introduction

• Light commercial unitary HVAC
• Introduced to ASHRAE TC 8.11 at Winter

meeting in Orlando, Jan 2010

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Current Code Requirements (Mandatory)

• §125 Acceptance requirements
• Functional tests (performance verification) performed
• n select lighting, envelope, & HVAC systems
• Acceptance tests are conducted:
• After construction and start-up
• Before occupancy and normal use of the equipment
• Who can perform the tests:
• Licensed mechanical engineer, civil engineer,

architect or contractor

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Current Code Requirements (Mandatory)

• NA7.5.4 Air Economizer Controls

Acceptance Test

• In-field functional tests

1.

Cooling demand, economizer 100% open

2.

Cooling demand, economizer @ minimum position

3.

Heating demand, economizer @ minimum position

• If the economizer is factory installed and certified by

the manufacturer to the CEC, no field testing is required

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Current Code Requirements (Prescriptive)

§144(e) Economizer requirement for each individual system:

• cooling fan system with design supply

capacity > 2,500 cfm, and

• mechanical cooling capacity > 75,000 Btu/hr,

then: Shall include either:

• air economizer or
• water economizer

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Current Code Requirements (Prescriptive)

• Economizers shall be integrated
• Package units with stand-alone economizer

controller: 2-stage t-stat is necessary

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Typical Practice

• Economizer installation
• Installed > 75,000 Btu/hr per Title 24
• > 25 tons: mostly factory-installed
• < 25 tons: 75% of units are field-installed
• MicroMetl, CanFab have majority CA market

share

• Usually identical units for field/factory
• No mfgs have applied for certification

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Typical Practice

• Economizer installation
• < 20 min to install in field
• Set min. air position (rule of thumb)
• Set high-limit on economizer controller
• CO2 sensor if DCV specified
• Performance verification is uncommon

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposal 1a

• Require economizers to be factory-

installed

• Quality control checkout procedures at the

plant improve economizer operation

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposal 1b

• Require durability certification, which could

include:

• temperature sensor calibration
• maximum damper leakage
• minimum damper duty cycles
• integrated economizer control
• high limit switch certification
• economizer enable/disable deadband

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Initial Data / Findings

Architectural Energy Corporation: http://www.energy.ca.gov/pier/project_reports/500-03-082.html

• AEC Study –215 RTUs

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Initial Data / Findings

• NBI Study –503 RTUs
• 64% of economizers had problems
• Broken, frozen or missing drive system components
• Outside air or mixed air sensor failure
• Faulty repairs
• Low changeover temperature set point
• Use of a single-stage cooling thermostat
• 42% of systems had incorrect airflow
• 20% had failed sensors

New Buildings Institute, Commercial Rooftop Unit Field Studies: http://www.newbuildings.org

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposals

• SECTION 144 – Prescriptive Requirements

For Space Conditioning Systems (e) Economizers. …

• 4. Air economizers shall be factory-installed and

certified by the manufacturer according to the requirements in § xxx

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Planned Data Collection and Analysis

• Lab testing
• Pilot test the durability requirements
• Economizer sensor & switch durability testing
• Work by AEC, NBI, PECI, others
• Focused market, cost, and energy savings

research

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Specific Stakeholder Requests

1.

What are manufacturers currently doing for durability testing?

2.

Is the testing conducted in-house or by a third party?

3.

How often or what is the sample size for testing? (e.g. once before new model introduction, one unit per year, one unit per every 10,000 assembled, etc.)

4.

What drives the market toward field-installed economizers?

5.

Are manufacturers set up to do factory-installed economizers?

6.

Where do manufacturers obtain their economizers? (CanFab, MicroMetl, ?)

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing QUESTIONS & COMMENTS

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposal 2

• Require economizer on smaller AC along with

compliant T-stats (2-stage or electronic)

≥ 54,000 Btu/h 90.1 Proposed Add. cy to be determined 2011 Title 24 ≥ 75,000 Btu/h 2008 Title 24 ≥ 65,000 Btu/h ASHRAE 90.1-2007 ≥ 33,000 Btu/h ASHRAE 189

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Initial Data / Findings

Architectural Energy Corporation: http://www.energy.ca.gov/pier/project_reports/500-03-082.html

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Initial Data / Findings

• Product is available
• @ 65 kBtuh to meet 90.1-2007
• @ 54 kBtuh to meet OR-2007
• Cost effective per ASHRAE methodology

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposals

• SECTION 144 – Prescriptive Requirements

For Space Conditioning Systems (e) Economizers.

• 1. Each individual cooling fan system that has a design

supply capacity over 2,500 cfm and a total mechanical cooling capacity over 75,000 Btu/hr shall include:

• A. An air economizer capable of modulating outside-air and

return-air dampers to supply 100 percent of the design supply air quantity as outside-air

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Planned Data Collection and Analysis

• Market/cost study
• Telephone survey w/HVAC distributors
• 5 regions x 3 mfgs x various capacity
• SF Bay Area, Inland Empire, Los Angeles,

Sacramento, San Diego

• Product availability
• Costs for initial purchase, installation,

maintenance, other recurring costs

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Planned Data Collection and Analysis

• Building energy simulation
• In representative climate zones
• Incrementally lower the unit capacity
• 10 bldg types:
• fast food restaurant
• sit-down restaurant
• small retail
• large retail
• primary school
• secondary school
• small office
• supermarket
• hotel
• warehouse

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing QUESTIONS & COMMENTS

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Current Code Requirements (Mandatory)

• §122(e) Each space-conditioning system

shall be installed with controls that automatically shut off the system during periods of nonuse and shall have:

• A. An automatic time switch control with a manual
• verride that allows operation of the system for up

to 4 hours; or

• B. An occupancy sensor; or
• C. A 4-hour timer that can be manually operated.

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Typical Practice

• We believe typical practice is:
• An automatic time switch control with a manual
• verride that allows operation of the system for up to

4 hours

• This is basically a commercial grade t-stat
• Occupied schedule is incorrect for some % t-stats

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposal 3

• Spaces required to have occupancy

sensors are required to setback thermostat or reduce VAV airflow when room is unoccupied

• Offices ≤ 250 sf
• Multipurpose rooms < 1000 sf
• Classrooms
• Conference rooms

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Initial Data / Findings

• > 5 mfgs w/ t-stats that accept occupancy

sensors

• Cost study for occupancy sensors completed by

HMG

$108.89 $91.75 Dual technology $137.19 $99.21 Ultrasonic $62.20 $49.91 Infrared Low Voltage Line Voltage

Average Price of Ceiling-Mounted Occupancy Sensors

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposals

Add new language to § 122(e) – Required Controls for Space-Conditioning Systems Similar language as current § 131(d)4

• Offices 250 square feet or smaller; multipurpose rooms
• f less than 1000 square feet, and classrooms and

conference rooms of any size, shall be equipped with

• ccupant sensor(s) to setup the operating cooling

temperature set point by 4°F or more and setdown the

• perating heating temperature set point by 4°F or more.

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Planned Data Collection and Analysis

• Technology issues
• T-stat relies on lighting line voltage or
• ccupancy sensor output
• Output impedance of the occ. sensor must be

compatible w/ t-stat’s input impedance

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Planned Data Collection and Analysis

• Market/cost study
• Telephone survey w/HVAC & lighting contractors
• 5 regions x 3 contractors
• SF Bay Area, Inland Empire, Los Angeles,

Sacramento, San Diego

• Product availability
• Current state of market adoption
• Costs for initial purchase, installation,

maintenance, other recurring costs

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Planned Data Collection and Analysis

• Building energy simulation
• In representative climate zones
• Incremental unit capacities
• 4 bldg types:
• Office ≤ 250 sf
• Multipurpose room < 1000 sf
• Classroom
• Conference room

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Specific Stakeholder Requests

1.

Field reports on the existing product lines that support this control method?

2.

Is this a separate control issue that doesn’t impact HVAC unit controls?

3.

Preference for cycling off/on vs. reduced airflow

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing QUESTIONS & COMMENTS

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Current Code Requirements

• A fault detection and diagnostics (FDD) system for DX

packaged units provides compliance credit in the performance calculation method

• COOL-EIR-FT curve adjusts efficiency of the cooling equipment
• If automated FDD, use multiplier 0.95 instead of 0.90
• New 2008 acceptance requirement:
• NA7.5.11 Fault Detection and Diagnostics (FDD) for Packaged

Direct-Expansion Units

• Construction inspection
• Functional tests: low airflow, refrigerant charge, sensor

calibration

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Typical Practice

• Light commercial unitary HVAC:
• 54% of HVAC energy use in commercial sector
• contributes to peak demand periods
• poorly maintained
• high % are broken
• Current practice is not to use FDD
• Product with FDD are early in their production cycle

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposal 4

• FDD requirement with signaling capability to t-stat or

exterior gateway

• FDD could test the following functions:
• Compressor enabled
• Economizer enabled
• Heating enabled
• Sensor calibration
• Damper position
• Economizer high limit
• Airflow
• Refrigerant charge
• Fan speed and operation
• Integration between economizer/compressor

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Initial Data / Findings

• Including FDD is technically feasible
• FDD is cost effective
• initial cost is ~ $300
• annual energy savings $400-$1000
• additional savings from equipment life savings, unnecessary

service and repairs (incorrect fault diagnosis)

• The crux may be a timing issue as product cycle matures
• Stand alone diagnostic systems are available that may

be appropriate for larger systems

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Potential Code Change Proposals

• Currently a compliance credit in the performance

calculation method

• Not required by Title 24
• Credit toward complying with energy budget
• Transition to a prescriptive requirement
• Not required by Title 24
• Sets the basis of performance standard

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Planned Data Collection and Analysis

• Refer to benefits/costs analysis conducted for 2008 Title

24 FDD changes

• Work by AEC, NBI, PECI, Purdue, others
• Focused market, cost, and energy savings research
• Determine if appropriate capacity for FDD features

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing

Specific Stakeholder Requests

1.

What is the projected timeline for introducing product with FDD?

2.

What FDD features are being considered?

3.

What is the means for a signaling capability to report status and faults?

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Controls & Economizing QUESTIONS & COMMENTS

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California Statewide Utility Codes and Standards Program

NR13 Outside Air

Non-Residential HVAC Stakeholder Meeting #1

Jim Meacham CTG Energetics April 27, 2010

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

4/27/2010

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NR13 Outside Air Overview

• 1. Outside air acceptance testing requirements
• 2. Reduced ventilation after economizing
• 3. In-situ DCV performance
• 4. Multi-point DCV sensor testing (LBNL)

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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NR13 Outside Air

• Summary of current code requirements
• Typical practice
• Summary of potential code change proposals
• Initial data/findings
• Potential code change proposals
• Planned data collection and analysis
• Specific stakeholder requests

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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NR13 Outside Air

Current Code Requirements

• OA Acceptance Testing [NA7.5.1; MECH-2A]
• CAV systems;VAV systems: two point
• VAV min: min VAV flow position or 30% supply flow
• VAV max: max VAV flow or full cooling
• OA flow control “system” calibration
• Flow station
• Differential Pressure
• SA/RA flow calc
• Outside air flow control stabilization (5 minutes)
• Pre-occupancy purge only req’d for CV/SZ/unitary

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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NR13 Outside Air

Current Code Requirements

• DCV Acceptance Testing [NA7.5.5; MECH-6A]
• Sensor calibration
• High/Lo CO2 level tests (600ppm diff)
• Reduced Ventilation [§121(c)1]
• Max 5 min reduction, must maintain total min OA

delivery for the hour

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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NR13 Outside Air

Current Code Requirements

• DCV System [§121(c)3,4]
• High occupancy (>25ppl/1000SF)
• Econ with SZ or DDC MZ
• Continuous high occ exempted
• 3-6ft above floor; 600ppm differential
• Area-based vent reduction reqt

CA Utilities 2011 Title 24 CASE Stakeholder Meeting for Proposed Code Changes

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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NR13 Outside Air

Current Code Requirements

• DCV Sensors [§121(c)3,4]
• +-75ppm accuracy from manufacturer
• Calibrated at factory or on start-up
• Min 5 yr calibration interval
• On failure – revert to full 121(b)2 vent reqts
• Sensor display and recording

CA Utilities 2011 Title 24 CASE Stakeholder Meeting for Proposed Code Changes

4/27/2010 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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NR13 Outside Air

Typical Practice

Acceptance Testing:

• TAB contractors responsible
• Calibrations often not verified
• System dynamics not appropriately represented
• OA is a function of supply flow, return, exhaust, dampers, etc
• Accurate measurements difficult
• Access, turbulence, ambient wind, instruments
• Two point control for VAV often not implemented
• Higher compliance w/dedicated min OA dampers/FS

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

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NR13 Outside Air

Typical Practice

DCV:

• Sensors not field calibrated, often not checked
• Poorly defined calibration schedules and processes
• Sensors not meeting requirements from factory
• No mechanism to adjust OA on sensor failure
• Buildings with DCV systems have OA flow rates well

below T24 standards (observed)

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NR13 Outside Air

Potential Code Change Proposals

OA Acceptance Testing

• Move pre-occupancy purge verification to OA

acceptance tests (NA7.5.1)

• Add verification of proper location of OA ducts in

plenum systems

• Add language to specify all system conditions at

min/max supply flow (compliance manual)

• Supply, return, exhaust/relief fans and dampers

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NR13 Outside Air

Potential Code Change Proposals

OA Acceptance Testing (cont’d)

• Correct inconsistency in OA damper stabilization

time: (5 mins [CM] vs. 15 mins [MECH-2A])

• Consider specifying acceptable technologies/

strategies for OA control for certain systems

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NR13 Outside Air

Potential Code Change Proposals

DCV

• Require CO2 sensor check/ calibration during

acceptance testing for all sensors

• Verification of CO2 sensor display and recording in

DDC systems Manufacturers:

• Improve accuracy and potentially “certify” sensors

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NR13 Outside Air

Initial Data / Findings

LBNL DCV findings (Fisk, et al):

• Multi-cal check: 760/1010ppm
• More than 40% of sensors had errors >±75ppm

(46%/40% @ 760/1010ppm)

• AVG of absolute value of error was >118ppm
• 19% had errors >200ppm at 1010ppm
• Single-cal check
• Average error = 60ppm
• Average of absolute value = 154ppm
• Errors at sensors, not BMS

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NR13 Outside Air

Initial Data / Findings

Reduced Ventilation (after economizing):

• Most extreme climates may yield up to 0.02kWh/SF of

savings

• Office, area-based, 12dT in an hour, no OA for 20 minutes

following economizing

• Actual savings will be significantly less
• Controls would be extremely difficult
• Verifying economizer performance (OA flow)
• Additional min damper position controls/ time control
• Occupancy and space dynamics

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NR13 Outside Air

Potential Code Change Proposals

• OA Acceptance Tests: Move pre-
• ccupancy purge verification to OA

acceptance tests (NA7.5.1)

• Verification only in SZ/unitary tests (NA7.5.2),

but referenced in code for all systems [121(c)2]

• No significant cost to verify schedule
• Low barriers to adoption
• Current compliance issues

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NR13 Outside Air

Potential Code Change Proposals

• OA Acceptance Tests: Add verification of

proper location of OA ducts in plenum systems

• OA ducts within 5ft or 15ft and >500FPM

velocity

• More performance implications needed
• No significant cost to verify location
• Low barriers to adoption

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NR13 Outside Air

Potential Code Change Proposals

• DCV Acceptance Tests: Add verification of

CO2 sensor display and recording in DDC systems

• Improve detection of failed sensors
• Small added cost to verify trending in BAS
• Med barriers to adoption – complexities with

trending/alarming in DDC

• Enforcement difficult

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NR13 Outside Air

Potential Code Change Proposals

• Require CO2 sensor check/ calibration

during acceptance testing for all sensors

• Improve detection of failed sensors
• Calibration costs could be high – varies by

technology and manuf.

• Med barriers to adoption
• Current compliance issues

CA Utilities 2011 Title 24 CASE Stakeholder Meeting for Proposed Code Changes

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NR13 Outside Air

Planned Data Collection and Analysis

• Survey of existing buildings with DCV systems to determine actual

OA flow rates

• Compare with non-DCV buildings, design data, and T24

standards

• Need help identifying potential DCV buildings/ systems in CA
• Any already tested (OA) in other work?
• Looking at code performance – are DCV systems delivering

savings? Meeting vent requirements?

• Building on LBNL work

CA Utilities 2011 Title 24 CASE Stakeholder Meeting for Proposed Code Changes

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NR13 Outside Air

Planned Data Collection and Analysis

• In-situ multipoint DCV sensor testing (LBNL)
• Need multi-point sites
• More data on existing OA acceptance testing methods and results

(TAB, building code officials, other stakeholders)

• Review of 2010 projects to date

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NR13 Outside Air

Specific Stakeholder Requests

• Acceptance Testing
• Copies of acceptance reports
• Connections to folks performing the testing
• Instrumentation preferences/ best practices
• OA flow monitoring station, “system” control

experience

• Two point control implementation

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NR13 Outside Air

Specific Stakeholder Requests

• DCV
• Sensor performance/ preferences
• Calibration experience
• Actual min OA rates in the field (design and in
• perations)
• Multi-point sensor experiences

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NR13 Outside Air

QUESTIONS & COMMENTS

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California Statewide Utility Codes and Standards Program

ASHRAE 3 - Energy Recovery for High Minimum Outside Air Systems

Non-Residential HVAC Stakeholder Meeting #1

Jeff Stein Taylor Engineering, LLC April 27, 2010

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ASHRAE 3 - Energy Recovery for High Minimum Outside Air Systems

• Summary of current code requirements
• Typical practice
• Summary of potential code change proposals
• Initial data/findings
• Potential code change proposals
• Planned data collection and analysis
• Specific stakeholder requests

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Current Code Requirements

• No current code requirements in Title 24
• ASHRAE 90.1 Addendum E requires 50% enthalpy

effectiveness energy recovery under these conditions:

Almost all

• f CA

Imperial County Alpine, Mono

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

90.1 ERV Exceptions

• (a) Laboratory systems meeting 6.5.7.2.
• (b) Systems serving spaces that are not cooled and that are heated to less than 60°F.
• (c) Systems exhausting toxic, flammable, paint, or corrosive fumes or dust.
• (d) Commercial kitchen hoods used for collecting and removing grease vapors and

smoke.

• (e) Where more than 60% of the outdoor air heating energy is provided from site-

recovered or site solar energy.

• (f) Heating energy recovery in climate zones 1 and 2. (HOT + HUMID)
• (g) Cooling energy recovery in climate zones 3c, 4c, 5b, 5c, 6b, 7, and 8.
• (h) Where the largest source of air exhaust at a single location at the building exterior

is less than 75% of the design outdoor air flow rate.

• (i) Systems requiring dehumidification that employ energy recovery in series with the

cooling coil.

• (j) Systems expected to operate less than 20 hrs per week at the outdoor air

percentage covered by table 6.5.6.1A

Much of CA Coast (e.g. San Mateo, Sonoma, Ventura)

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ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

90.1 ERV Exceptions for Labs

• Basically Labs with VAV or direct makeup are exempt
• 6.5.7.2 Laboratory Exhaust Systems.
• Buildings with laboratory exhaust systems having a total exhaust rate greater than 5000 cfm shall include at least
• ne of the following features:

1.

VAV laboratory exhaust and room supply system capable of reducing exhaust and makeup air flow rates and/or incorporate a heat recovery system to precondition makeup air from laboratory exhaust that shall meet the following:

• A + B×(E/M) ≥ 50%
• Where:
• A = Percentage that the exhaust and makeup air flow rates can be reduced from design conditions.
• B = Percentage sensible recovery effectiveness.
• E = Exhaust airflow rate through the heat recovery device at design conditions
• M = Makeup air flow rate of the system at design conditions.

2.

VAV laboratory exhaust and room supply systems that are required to have minimum circulation rates to comply with code or accreditation standards shall be capable of reducing zone exhaust and makeup air flow rates to the regulated minimum circulation values, or the minimum required to maintain pressurization relationship requirements. Non regulated zones shall be capable of reducing exhaust and makeup air flow rates to 50% of the zone design values, or the minimum required to maintain pressurization relationship requirements.

3.

Direct makeup (auxiliary) air supply equal to at least 75% of the exhaust air flow rate, heated no warmer than 2°F below room setpoint, cooled to no cooler than 3°F above room setpoint, no humidification added, and no simultaneous heating and cooling used for dehumidification control.

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ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Typical Practice

• ERV is used on some “green” hospitals and labs

but is not typical practice

• ERV is not typical practice on other applications

(e.g. office, retail) but minimum OA rates are usually not that high.

• Where min OA rates are high (e.g. schools)

Demand Control Ventilation with CO2 is more common than ERV

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Potential Code Change Proposals

• Similar or perhaps identical requirements

as 90.1 Addendum E

• Sensible only ERV in coastal climates with

high min OA

• Sensible + Latent ERV in inland climates

with high min OA

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Where Might It Apply?

• Labs and Hospitals – not currently covered by

Title 24 but may be included in the future

• Retail, Schools, etc. – designers may increase

minimum OA to improve air quality or get LEED points.

• Our analysis may find ERV to be cost-effective

in more cases than the ASHRAE analysis, e.g. at lower minimum OA

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Initial Data / Findings

• We will use the ASHRAE analysis to inform our analysis, e.g.:

$/CFM

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Planned Energy Analysis

• At least 36 DOE-2 simulation runs in the first phase of analysis
• Prototype Buildings (2 total)
• Office/School – low internal, air cooled packaged AC with economizer, gas boiler

heat,

• 24/7 (Hospital/Lab) - High internal loads, High air change rate (8 air changes?),

water-cooled chilled water, gas boiler

• % min OA (3 total) –35%, 70%, 100%
• System Type (2 total)
• Multizone VAV Reheat - relatively fixed SAT setpoint, bypass damper
• Constant Volume Single Zone - SAT setpoint tracks space load, No bypass

damper

• Climate Zones (3 total, initially)- CZ03 (San Francisco), CZ12 (Sacramento),

CZ09 (Los Angeles)

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Planned Energy Analysis – Key Assumptions / Sensitivity Analysis

• ERV Performance Assumptions – effectiveness, pressure drop, fan
• efficiency. Options:
• Use ASHRAE analysis (e.g. 62% effectiveness, 1.2” pressure drop)
• Use Addendum E minimum (50% effectiveness)
• Use actual selections from manufacturers
• Pay stipends to local equipment representatives to provide actual selections
• Exfiltration and Miscellaneous Exhaust - affect OA/EA ratio and actual

effectiveness

• ASHRAE analysis assumed 0.16 CFM/ft2
• Condensation/Frost Control
• Consult ERV manufacturers to determine which of the 4 options in eQUEST are

appropriate for each CA climate zone

• Failure Rate – ERV can fail without being noticed
• Sensitivity analysis: 0%, 10% and 20% failures

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Planned Incremental Cost Analysis

• Maintenance Costs
• Ask Service Contractors
• Use ASHRAE analysis data (no references)
• First Costs
• Use ASHRAE analysis (no references)
• Develop a series of equipment specifications covering various sizes of

equipment with and without ERV (e.g. 5 tons, 15 tons, 35 tons, 75 tons) and pay equipment reps to provide pricing and equipment selections

• Throw out outliers?
• Pay mechanical and general contractors to estimate other incremental costs

based on actual selections and typical designs:

• Ducting of exhaust to the air handler (e.g. labs)
• Labor, if ERV is field installed
• Rigging and structural, based on added weight
• Chiller plant/piping downsizing
• Others?

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems

Specific Stakeholder Requests

• Incremental Cost Data
• Case studies: high OA rates, ERV
• Contacts?

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems QUESTIONS & COMMENTS

91

California Statewide Utility Codes and Standards Program

HVAC Efficiency and Baseline

Non-Residential HVAC Stakeholder Meeting #1

Abhijeet Pande Heschong Mahone Group, Inc. April 27, 2010

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HVAC Efficiency and Baseline

• Summary of current code requirements
• Typical practice
• Summary of potential code change proposals
• Initial data/findings
• Potential code change proposals
• Planned data collection and analysis
• Specific stakeholder requests

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Current Code Requirements

• Title 24 - Standard HVAC System Selection

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Current Code Requirements

• Title 24 - HVAC System Efficiency

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Current Code Requirements

• Title 24 - HVAC System Efficiency

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Current Code Requirements

• Evaporative Cooling
• The ACM provides path for modeling evaporative

cooling through optional ‘System 9’ (§3.3.5)

• Stand-alone evaporative cooling systems, and
• Evaporative cooling as pre-cooling for other systems
• Inputs needed for modeling
• Evaporative cooler fan capacity and brake horsepower (bhp)
• Water pump capacity and brake horsepower (bhp)
• Whether evap cooling is stand-alone or as pre-cooling
• Default inputs provided
• Direct cooling efficiency
• Indirect cooling efficiency
• Can be changed by user

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HVAC Efficiency and Baseline

Current Code Requirements

• Prescriptive requirement for all space

conditioning equipment (2008 T24 §144(b)3.)

• Indoor design temperature and humidity conditions for

general comfort applications shall be determined in accordance with ASHRAE Standard 55 or

• ASHRAE Handbook, Fundamentals Volume,

Chapter 8

• Except that winter humidification and summer

dehumidification shall not be required.

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Typical Practice

• New construction: Packaged rooftop units dominant type
• f air conditioners for commercial buildings

Data Source: California Nonresidential New Construction Baseline Report RLW Analytics Inc., 1999

Single Package Rooftop Heat Pump 15% Single Package Rooftop AC 65% Split System AC 9% Evaporative System 3% Water Loop Heat Pump 6% Split System Heat Pump 2%

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Typical Practice

• Retrofits: Typically done with like systems, often at

minimal efficiency gains or at prescribed minimum federal efficiency levels

• Higher efficiency projects (e.g.LEED) use
• Higher efficiency Dx systems
• Higher efficiency alternate systems such as
• Indirect or indirect/direct evaporative cooling
• Radiant cooling

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Potential Code Change Proposals

• Base Code:
• Performance credits for Indirect, Indirect/Direct evaporative

cooling

• Stand-alone systems
• As pre-cooling for other systems (Dx)
• Path for higher baseline efficiency?
• Thermal Comfort reporting
• Using ASHRAE Std 55-2004
• Reach Code:
• Baseline systems using alternative systems
• Evaporative cooling
• Radiant cooling
• Others?

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HVAC Efficiency and Baseline

Initial Data / Findings

• Western Cooling Challenge
• ASHRAE Std 55-2004

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Initial Data / Findings

• Western Cooling Challenge
• Established by the Western Cooling Efficiency Center
• Goals:
• 40% reduction in energy use and peak demand of roof-top

units (RTUs) through

– Development of new products and improvements to existing products

• Target – RTUs between 3-20 tons, manufacturing capacity

>500-units/yr

• Extensive laboratory testing of equipment at several design

conditions

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HVAC Efficiency and Baseline

Initial Data / Findings

• Western Cooling Challenge
• Collaborative effort with industry
• 12 industry partners (OEMs and component

suppliers)

– AMAX, Coolerado, Desert Aire, Ice-Energy Incorporated, Integrated Comfort Inc, Munters, Munters-Des Champs Technologies, NovaTorque Inc., Seeley International Pty Ltd., Thermal-Flow, Trane.

• Product development
• Laboratory testing of equipment

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HVAC Efficiency and Baseline

Initial Data / Findings

• First system to

exceed the goals announced in Jan 2010

• Targets small

commercial applications (5-ton RTU)

• Energy savings up

to 80% compared to baseline system

Source: Technical Report , NREL/TP-550-46524 September 2009

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Initial Data / Findings

• ASHRAE Standard 55-2004: “Thermal

Environmental Conditions for Human Occupancy”

• Specifies conditions in which majority of occupants in the

space will find the space thermally comfortable

• Based on “Predicted Mean Vote (PMV)” and “Predicted

Percent of Dissatisfied (PPD)” or PMV-PPD metric

• PMV-PPD based on field evaluations and meta-analysis
• Two personal variables: Activity, Clothing
• Four environmental variables: Temperature, Thermal

Radiation, Humidity and Air Speed

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HVAC Efficiency and Baseline

Initial Data / Findings

• ASHRAE Standard 55-2004
• PMV is an index that predicts the mean value of

votes of a large group of persons on a 7-point thermal sensation scale

• PPD is an index of percentage of people thermally

dissatisfied based on the PMV

Hot Warm Slightly Warm Neutral Slightly Cool Cool Cold 3 2 1

• 1
• 2
• 3

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

ASHRAE Standard 55-2004

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Potential Code Change Proposals

• Develop Performance Path Requirements
• Thermal Comfort metrics reporting
• Compliance credits for evaporative cooling

systems

• Evaluate energy and peak demand savings
• Account for water usage and comfort metrics
• Develop Reach Code requirements for

HVAC using alternative systems

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Planned Data Collection and Analysis

• Conduct literature review of advanced evaporative cooling system
• Savings potential
• Costs (equipment and installed)
• Conduct energy simulation modeling
• Using EnergyPlus or other appropriate software
• In representative climate zones
• Use existing prototypes from past code cycles, modified as necessary
• Compare energy savings and thermal comfort improvements
• Conduct life-cycle costing analysis
• Using standard CEC LCC criteria
• Evaluate water usage of evaporative cooling systems

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline

Specific Stakeholder Requests

• Feedback on measure/product
• Technical information
• Market practices
• Costs and availability
• Product development plans

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

HVAC Efficiency and Baseline QUESTIONS & COMMENTS

112

California Statewide Utility Codes and Standards Program

NR 10 - Single Zone VAV

Non-Residential HVAC Stakeholder Meeting #1

Jeff Stein Taylor Engineering, LLC April 27, 2010

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NR 10 - Single Zone VAV

• Summary of current code requirements
• Typical practice
• Summary of potential code change proposals
• Initial data/findings
• Potential code change proposals
• Planned data collection and analysis
• Specific stakeholder requests

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NR 10 - Single Zone VAV

Current Code Requirements

• Title 24-2008:
• Effective 1/1/2012, DX and chilled water (CHW) units ≥ 10 tons

shall be VAV

• (have VFD or 2 speed supply fans to reduce speed below 2/3 of full

speed at low load)

• ASHRAE 90.1-2010:
• Effective 1/1/2010, CHW units ≥ 5 hp shall be VAV
• Effective 1/1/2012, DX units ≥ 10 tons shall be VAV

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

NR 10 - Single Zone VAV

Typical Practice

• Typical practice for single zone (SZ) units (CHW

and DX) is constant volume

• We estimate less than 5% of SZ DX units are

VAV

• We estimate less than 10% of SZ CHW units are

VAV

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

NR 10 - Single Zone VAV

Potential Code Change Proposals

• All CHW SZ Units shall be VAV
• VFD and ECM motor costs have come down

dramatically in recent years

• We expect the fan and cooling savings to pay

for the VFD/ECM for all sizes

• Effective 1/1/2015 DX units ≥ 3 tons shall

be VAV

• The effective date and size will be negotiated

with AC manufacturers

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

NR 10 - Single Zone VAV

New Products in Recent Years

• DX
• 4 ton VAV packaged units with variable capacity compressors
• 2 ton digital scroll compressors
• 3 to 11 ton variable speed scroll compressors
• 1 ton mini-splits with variable speed compressors
• Multizone variable refrigerant flow (VRF) systems down to 4 tons
• ECM motors standard on many small packaged units
• CHW
• ECM motors standard option on many fan coils and unit ventilators
• Fractional horsepower VFDs are cheap and easy to add to fan coils

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

NR 10 - Single Zone VAV

Planned Analysis for DX

• Engage DX Manufacturers and AHRI
• Survey
• Do you or can you have products that meet the

phase-in date?

• Do you support or oppose the proposal?

– if oppose, why?

• What code requirements would you support?
• Conduct lifecycle cost analysis

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NR 10 - Single Zone VAV

Lifecycle Analysis for DX

• Energy
• DOE-2 model of 5-zone office building in all climates

to find statewide average savings/ton

• Equipment efficiencies based on real selections
• Incremental First Cost
• Solicit real equipment prices from reps
• higher min OA cost for VAV
• Adjust for market share (VAV prices will come down

when market share rises)

• Incremental Maintenance
• Survey vendors, manufacturers, and/or warranty

service providers

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NR 10 - Single Zone VAV

Planned Analysis for CHW

• 2 prototypes
• CHW air handler serving auditorium
• occupied 20 hrs/week
• with and without economizer, i.e. above and below

7 tons

• CHW fan coil serving computer room
• 24/7
• No economizer
• First Cost and Maintenance
• Solicit from equipment reps (same as DX)

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NR 10 - Single Zone VAV

Specific Stakeholder Requests

• Case studies
• Equipment selections with pricing
• Maintenance costs

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NR 10 - Single Zone VAV QUESTIONS & COMMENTS

123

California Statewide Utility Codes and Standards Program

NR12 – Reduce Reheat

Non-Residential HVAC Stakeholder Meeting #1

Jeff Stein Taylor Engineering, LLC April 27, 2010

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NR12 – Reduce Reheat

• Summary of current code requirements
• Typical practice
• Summary of potential code change

proposals

• Initial data/findings
• Planned data collection and analysis
• Specific stakeholder requests

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NR12 - Reduce Reheat

Current Title 24 Reheat Exceptions

EXCEPTION 1 to Section 144(d): Zones served by variable air-volume systems that are designed and controlled to reduce, to a minimum, the volume of reheated, re-cooled, or mixed air supply are allowed only if the controls meet the following requirements:

• A. For each zone with direct digital controls (DDC):

The volume of primary air that is reheated, re-cooled, or mixed air supply shall not exceed the larger of:

• a. 50 percent of the peak primary airflow, or
• b. The design zone outdoor airflow rate per Section 121.

The primary airflow in the deadband shall not exceed the larger of:

• a. 20 percent of the peak primary airflow; or
• b. The design zone outdoor airflow rate per Section 121.

Airflow between deadband and full heating or full cooling must be modulated.

• B. For each zone without DDC, the volume of primary airflow that is reheated, re-cooled, or mixed air supply shall not

exceed the larger of the following:

• a. 30 percent of the peak primary airflow; or
• b. The design zone outdoor airflow rate per Section 121.

EXCEPTION 2 to Section 144(d): Zones with special pressurization relationships or cross-contamination control needs. EXCEPTION 3 to Section 144(d): Zones served by space-conditioning systems in which at least 75 percent of the energy for reheating, or providing warm air in mixing systems, is provided from a site-recovered or site-solar energy source. EXCEPTION 4 to Section 144(d): Zones in which specific humidity levels are required to satisfy process needs. EXCEPTION 5 to Section 144(d): Zones with a peak supply-air quantity of 300 cfm or less.

A = Dual Max (described later) B = Single Max (described later)

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NR12 - Reduce Reheat

Typical Practice

• Low density zones (e.g. private office): VAV reheat
• High density zones (e.g. classroom, conference room):
• VAV reheat with demand control ventilation (CO2), or
• Series or parallel fan powered box

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NR12 - Reduce Reheat

Typical T24 DDC Zone

• [Summarize what we believe typical practice is.

Ask for feedback on whether this is correct.]

Supply Air Temperature Setpoint 50% or vent. Max Cooling Airflow Setpoint 20%, or vent. Heating Loop Cooling Loop Maximum Supply Air Temperature Airflow Setpoint Dead Band (shaded area = reheat)

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NR12 - Reduce Reheat

Typical Pneumatic Zone (also DDC in 90.1)

Reheat Valve Position Maximum Airflow Setpoint 30%, or vent. Heating Loop Cooling Loop Airflow Setpoint Dead Band (shaded area = reheat)

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NR12 - Reduce Reheat

Potential Code Change Proposals

• Option 1: Adopt ASHRAE Standard 189.1

Reheat Exception:

• Zones for which the volume of air that is

reheated, recooled, or mixed is no greater than the larger of the following:

(1) the design outdoor airflow rate for the zone, or (2) 15% of the zone design peak supply rate.

• Option 2: Revisit 20%/50% dual maximum

– e.g. go to 15%/40%

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NR12 - Reduce Reheat

189.1 versus 90.1

• [Present any data you have already
• btained or analyzed, and how it will

inform the CASE study]

Reheat Valve Position Maximum Airflow Setpoint 30%, or vent. Heating Loop Cooling Loop Airflow Setpoint Dead Band (shaded area = reheat) 189.1 max airflow 15%, or vent.

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NR12 - Reduce Reheat

189.1 versus Title 24

Supply Air Temperature Setpoint 50% or vent. Max Cooling Airflow Setpoint 20%, or vent. Heating Loop Cooling Loop Maximum Supply Air Temperature Airflow Setpoint Dead Band (shaded area = reheat) 15%, or vent. 189.1 max airflow Parallel fan box ON

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NR12 - Reduce Reheat

Title 24 (dual max) vs 90.1 (single max)

Dual Maximum Savings

$0.00 $0.05 $0.10 $0.15 $0.20 $0.25 $0.30 $0.35 $0.40 $0.45 $0.50

Base case Temperature reset 40% single min. 50% single min. Oversized sys. 24/7 Low load 24/7, low load, oversize 24/7, low load, oversize, 50% single min. San Francisco, base case San Francisco, worst code compliance L.A., base case L.A., worst code compliance Chicago, base case Chicago, worst code compliance Atlanta, base case Atlanta, worst code compliance Utility cost savings relative to single max. control [$/sf/yr]

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NR12 - Reduce Reheat

Planned Data Collection and Analysis

• Technical Feasibility
• Is 15% below controllable minimum of most VAV boxes?
• Energy Analysis
• Compare Fan Powered Box (15% min) to VAV Reheat Box (20%/50%)
• Sensitivity Analysis: Load Profile, Oversizing, SAT Reset, 24/7, heating max
• Assume average zone size to compare energy and cost
• Incremental Cost Analysis
• Box cost – equipment suppliers
• Installation and Maintenance – HVAC contractors
• Electrical – Electrical contractors
• How many zones are affected by lowering the heating maximum (e.g. from 50%

to 40%), i.e. convert from reheat to fan boxes?

• Implications for future adoption of ASHRAE Standard 62.1
• 15% may require DOAS because 62.1 gives less credit for transfer air

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NR12 - Reduce Reheat

Specific Stakeholder Requests

• Case studies on box stability at low flows
• Cost data on reheat versus fan boxes

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

NR12 - Reduce Reheat QUESTIONS & COMMENTS

136

California Statewide Utility Codes and Standards Program

Radiant Cooling

Non-Residential HVAC Stakeholder Meeting #1

Abhijeet Pande

Heschong Mahone Group, Inc.

Kristin Heinemeier

Western Cooling Efficiency Center

April 27, 2010

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137

Radiant Cooling

• Summary of current code requirements
• Typical practice
• Summary of potential code change proposals
• Initial data/findings
• Potential code change proposals
• Planned data collection and analysis
• Specific stakeholder requests

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Radiant Cooling

Current Code Requirements

• Prescriptive Requirements
• No specific requirements exist for radiant systems
• Performance approach – Nonresidential ACM
• For Primary Systems
• No system type defined for radiant cooling
• For Perimeter Systems
• Independent HVAC systems (typically heating only) which serve

perimeter zones in addition to a primary system (typically cooling

• nly).
• Perimeter systems differ from zone terminal systems in that they are

independent: They do not connect to the primary system but supply heating/cooling through separate air outlets or heat transfer surfaces.

• System 12: Convective/radiant. Zone perimeter system may be a

convective or radiant system, such as baseboard or radiant ceiling panels.

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Radiant Cooling

Current Practice

• Radiant cooling systems are being installed in

high-efficiency buildings to save energy and for a comfortable environment

• Wal-Mart as an example
• On March 19, 2008 Wal-Mart opened a Supercenter in Las

Vegas

• Estimated to be the most efficient cooling system in major

store in Western US:

– Should save up to 55% of cooling energy compared to conventional Supercenter

• Evaporatively cooled water circulated through tubing in

concrete floor slab

• Water cooled at night to reduce energy use and peak

demand

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Radiant Cooling

Typical Practice

• For compliance calculations, one can model the

radiant system using other system types as proxies

• Built-up single zone with cooling coil but no fan
• But how accurately does that reflect the true energy

consumption of radiant systems?

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Radiant Cooling

Potential Code Change Proposals

• Performance Approach
• Develop optional system type for radiant cooling in

the nonresidential ACM

• Limited to certain types of radiant systems and building types

(to start with)

• Review and revise ACM schedules to add

temperature set points appropriate for radiant cooling

• Develop intelligent defaults for the ACM model
• With user over-rides where appropriate

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Radiant Cooling

Planned Data Collection and Analysis

• Literature Review and Stakeholder Communication
• How are radiant systems currently modeled for code compliance
• How accurate are these calculations
• What tools and methods are used to evaluate radiant cooling systems for

engineering design applications

• Energy Analysis
• Develop prototype system(s)
• Develop modeling rule-sets
• Conduct simulation analysis for systems to establish feasibility of rule-sets and

potential savings from a radiant cooling system model

• ACM rules
• Develop radiant cooling system model rules for ACM
• Based on energy analysis and stakeholder feedback

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Radiant Cooling

Specific Stakeholder Requests

• Market Practices
• Radiant cooling applications
• Compliance calculation methods
• Engineering analysis methods
• Radiant system
• Technical information
• Costs
• Product development plans
• Other stakeholders who can provide input on

modeling procedures

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Radiant Cooling QUESTIONS & COMMENTS

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California Statewide Utility Codes and Standards Program

Water+Space Heating

Non-Residential HVAC Stakeholder Meeting #1

Yanda Zhang Heschong Mahone Group, Inc. April 27, 2010

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Water+Space Heating

• Summary of current code requirements
• Typical practice
• Summary of potential code change proposals
• Initial data/findings
• Potential code change proposals
• Planned data collection and analysis
• Specific stakeholder requests

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CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Water+Space Heating

Current Code Requirements

• Prescriptive Requirements
• No specific requirements exist for combined hydronic space

heating and water heating systems and for Variable Refrigerant Flow systems

• Performance approach – ACM
• Combined Space and Water Heating (CSWH)
• Energy budget calculation steps specified
• Standard Design definition
• Variable Refrigerant Flow (VRF)
• Not addressed

electric split system heat pump with HSPF meeting appliance efficiency regulation requirements for split systems. Electricity Any System 5- Four Pipe Fan Coil System with Central Plant

• r

System 1 or System 2 gas furnace with AFUE meeting appliance efficiency regulation requirements for central systems. Standard Design Any Hydronic NR-All residential including Hotel/Motel/Guest Room Gas or mix of electricity and

• ther source

Any R-All Proposed Design Heating Source Proposed Design System Type Building Type

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Water+Space Heating

Typical Practice

• Hydronic Space and Water Heating
• If fan coil system is used, air duct is usually located

within conditioned space – no credit should be given

• Combined system: share water heating equipment

and/or share distribution pipe

• Hydronic heating could be used with AC system
• VRF
• Benefit of better part load efficiency and heat reclaim

capability

• Not yet widely used due to cost, refrigerant safety,

and ventilation issue

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Water+Space Heating

Potential Code Change Proposals

• Hydronic Heating System
• Baseline changes: no energy budget for duct loss for

all hydronic systems

• Improved pipe heat loss and AFUE adjustment,

especially for combined space and water heating system

• Clarification of non-res standard design for hydronic

systems

• VRF System
• Adoption of ACM
• Possible credit

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Water+Space Heating

Initial Data / Findings

• Hydronic heating system ACM
• Calculate Water heating budget separately from Space

heating budget

• Credit provided to hydronic heating system without ducts
• Pipe heat loss is directly associated with heating load and is

accounted by using an effective AFUE

• Method for combined space and water heating system not

clearly defined to reflect boiler efficiency improvement and/or pipe loss reduction

• VRF
• EnergyPro VRF model developed with VRF manufacturers

that use better efficiency data and include a heat reclaim model

• Not sure if the performance data is certified

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Water+Space Heating

Planned Data Collection and Analysis

• Literature Review and Stakeholder Communication
• How are CSW and VRF systems currently modeled for code compliance
• How accurate are these calculations
• What tools and methods are used to evaluate CSW and VRF systems for

engineering design applications

• Energy Analysis
• Develop prototype systems
• Develop modeling rule-sets
• Conduct simulation analysis for systems to establish feasibility of rule-sets and

potential savings from a radiant cooling system model

• ACM rules
• Develop CSW and VRF model rules for ACM
• Based on energy analysis and stakeholder feedback

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Water+Space Heating

Specific Stakeholder Requests

• Combined Space and Water Heating
• Market practice: hydronic heating w/ and w/o ducts
• Pro and Con radiant and fan coil terminal heating
• Ventilation
• System cost
• VRF
• Market potential of VRF (hotel/motel/MF)
• Ventilation
• Certified data from equipment tested under new AHRI 1230

Standard

• System cost
• Compliance calculation method
• Other stakeholders who can provide input on modeling

procedures

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Water+Space Heating QUESTIONS & COMMENTS