20 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 ● CO 2 sensor if DCV specified ● Performance verification is uncommon CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
21 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
22 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
23 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing Initial Data / Findings ● AEC Study –215 RTUs Architectural Energy Corporation: http://www.energy.ca.gov/pier/project_reports/500-03-082.html CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
24 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
25 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
26 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
27 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing Specific Stakeholder Requests What are manufacturers currently doing for durability testing? 1. Is the testing conducted in-house or by a third party? 2. How often or what is the sample size for testing? (e.g. once 3. before new model introduction, one unit per year, one unit per every 10,000 assembled, etc.) What drives the market toward field-installed economizers? 4. Are manufacturers set up to do factory-installed economizers? 5. Where do manufacturers obtain their economizers? (CanFab, 6. MicroMetl, ?) CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
28 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing QUESTIONS & COMMENTS CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
29 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) ASHRAE 189 ≥ 33,000 Btu/h ASHRAE 90.1-2007 ≥ 65,000 Btu/h 90.1 Proposed Add. cy ≥ 54,000 Btu/h 2008 Title 24 ≥ 75,000 Btu/h 2011 Title 24 to be determined CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
30 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
31 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
32 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
33 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
34 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
35 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing QUESTIONS & COMMENTS CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
36 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 override 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. CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
37 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 override 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
38 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
39 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 Line Voltage Low Voltage Infrared $49.91 $62.20 Ultrasonic $99.21 $137.19 Dual technology $91.75 $108.89 Average Price of Ceiling-Mounted Occupancy Sensors CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
40 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 of less than 1000 square feet, and classrooms and conference rooms of any size, shall be equipped with occupant sensor(s) to setup the operating cooling temperature set point by 4°F or more and setdown the operating heating temperature set point by 4°F or more. CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
41 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 occupancy sensor output ● Output impedance of the occ. sensor must be compatible w/ t-stat’s input impedance CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
42 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
43 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
44 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing Specific Stakeholder Requests Field reports on the existing product lines that support this 1. control method? Is this a separate control issue that doesn’t impact HVAC 2. unit controls? Preference for cycling off/on vs. reduced airflow 3. CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
45 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing QUESTIONS & COMMENTS CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
46 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
47 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
48 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
49 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
50 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
51 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
52 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing Specific Stakeholder Requests What is the projected timeline for introducing product with 1. FDD? What FDD features are being considered? 2. What is the means for a signaling capability to report status 3. and faults? CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
53 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Controls & Economizing QUESTIONS & COMMENTS CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
54 NR13 Outside Air Non-Residential HVAC Stakeholder Meeting #1 California Statewide Utility Codes and Standards Program Jim Meacham CTG Energetics April 27, 2010
55 55 55 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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) CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
56 56 56 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
57 57 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
58 58 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
59 59 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 Stakeholder Meeting for Proposed Code Changes CA Utilities 2011 Title 24 CASE Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
60 60 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 Stakeholder Meeting for Proposed Code Changes CA Utilities 2011 Title 24 CASE Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
61 61 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
62 62 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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) CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
63 63 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
64 64 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
65 65 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
66 66 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
67 67 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
68 68 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM NR13 Outside Air Potential Code Change Proposals ● OA Acceptance Tests: Move pre- occupancy 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
69 69 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
70 70 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
71 71 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 Stakeholder Meeting for Proposed Code Changes CA Utilities 2011 Title 24 CASE Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
72 72 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
73 73 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 ● CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
74 74 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
75 75 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM NR13 Outside Air Specific Stakeholder Requests ● DCV ● Sensor performance/ preferences ● Calibration experience ● Actual min OA rates in the field (design and in operations) ● Multi-point sensor experiences CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
76 76 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM NR13 Outside Air QUESTIONS & COMMENTS CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010 4/27/2010
77 ASHRAE 3 - Energy Recovery for High Minimum Outside Air Systems Non-Residential HVAC Stakeholder Meeting #1 California Statewide Utility Codes and Standards Program Jeff Stein Taylor Engineering, LLC April 27, 2010
78 78 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
79 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 of CA Imperial County Alpine, Mono CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
80 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) CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
81 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 ● one of the following features: VAV laboratory exhaust and room supply system capable of reducing exhaust and makeup air flow rates 1. 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 . ● VAV laboratory exhaust and room supply systems that are required to have minimum circulation rates to 2. 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. Direct makeup (auxiliary) air supply equal to at least 75% of the exhaust air flow rate, heated no warmer 3. 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. CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
82 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CO 2 is more common than ERV CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
83 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
84 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
85 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
86 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) CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
87 ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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/ft 2 ● 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 ● CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
88 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? ● CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
89 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? CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
90 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM ASHRAE 3 -Energy Recovery for High Minimum Outside Air Systems QUESTIONS & COMMENTS CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
91 HVAC Efficiency and Baseline Non-Residential HVAC Stakeholder Meeting #1 California Statewide Utility Codes and Standards Program Abhijeet Pande Heschong Mahone Group, Inc. April 27, 2010
92 92 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
93 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Efficiency and Baseline Current Code Requirements ● Title 24 - Standard HVAC System Selection CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
94 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Efficiency and Baseline Current Code Requirements ● Title 24 - HVAC System Efficiency CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
95 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Efficiency and Baseline Current Code Requirements ● Title 24 - HVAC System Efficiency CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
96 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
97 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM 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. CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
98 CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM HVAC Efficiency and Baseline Typical Practice ● New construction: Packaged rooftop units dominant type of air conditioners for commercial buildings Single Package Rooftop AC 65% Single Package Rooftop Heat Pump 15% Split System AC 9% Data Source: Split System Heat Pump California Nonresidential 2% New Construction Baseline Report Water Loop Heat Pump RLW Analytics Inc., 6% Evaporative System 1999 3% CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
99 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 CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
100 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? CA Utilities 2011 Title 24 Stakeholder Meeting for Proposed Code Changes 4/27/2010
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