Presented by: name title date

Slides:



Advertisements
Similar presentations
Sustainable School Design Creating Healthy, High Performance School Facilities Presented by Stephen M. Koontz, Energy Services Leader, Tampa Bay Trane.
Advertisements

Chapter 3. HVAC Delivery Systems
Intro to Enersol What is Retro-commissioning? Define Benefits of Retro-commissioning Define Retro-commissioning Process Discuss Retro-commissioning Findings.
HEALTHCARE BUILDING AUTOMATION
Carrier Controls Demand Controlled Ventilation. Comfort = Temperature + Ventilation Comfort Is More Than Just The Right Temperature… Ventilation Control.
Heating, Ventilating, and Air-Conditioning
Objectives Control Terminology Types of controllers –Differences Controls in the real world –Problems –Response time vs. stability.
Commercial Mechanical Requirements
100% Outside Air and Dehumidification Management
TYPES OF MECHANICAL SYSTEMS
HVAC 101 The Basics of Heating, Ventilation and Air Conditioning
Foundations of Real Estate Management TM BOMA International ® Module 3: Building Operations I Heating, Ventilating, and Cooling the Building.
The Role of Controls for Indoor Air Quality Kent W. Peterson, PE, Fellow ASHRAE P2S Engineering, Inc. Mid Columbia ASHRAE Chapter.
Components of HVAC System
2005 Title 24 Nonresidential Acceptance Requirements Mechanical Designer Training Presented by Tav Commins California Energy Commission.
Learning Outcomes Upon completion of this training one should be able to: Identify open loop and closed loop campus-type hydronic water system applications.
Commercial Mechanical and Service Water Heating Requirements of 2012 International Energy Conservation Code.
Engineer Presentation
Student Book © 2004 Propane Education & Research CouncilPage Performing Pressure Tests on Gas Distribution Lines Gas personnel must understand.
Energy Management with the use of an Intelligent Building Management System.
Active beams versus VAV with Reheat Analysis of May 2013 ASHRAE Journal article Ken Loudermilk Vice President, Technology & Developement.
Product Introduction.
PTCS DUCT SEALING SPECIFICATIONS The Perfect Spec : Simple as possible Achievable by the motivated, not just the true believer Assure that energy savings.
AccuMax Multi-Point Injection Mechanics
Refrigeration and Heat Pump Systems Refrigeration systems: To cool a refrigerated space or to maintain the temperature of a space below that of the surroundings.
Copyright 2008, International Code Council 2012 IECC ® for SERBCA Based on the 2012 International Energy Conservation Code.
PSU Building Thermal and Mechanical Systems Laboratory Environment A/E Kurt M. Shank, M.S. & Stanley A. Mumma, Ph.D., P.E. College of Engineering Department.
An intelligent VAV zoning system
Static Pressure Control Loop The purpose of the static pressure control loop is to maintain an optimal static pressure in the ductwork. The control loop.
1 Connecticut’s New Energy Code Connecticut ASHRAE Tech Session October 13, 2011 Frederick F. Wajcs, Jr. Senior Energy Engineer Connecticut Light and Power.
Original Materials Developed By: Britt/Makela Group, Inc.
Brought to you by: Connecticut Energy Code Frederick F. Wajcs Senior Energy Engineer Northeast Utilities February 10, 2011.
Implementing Demand Controlled Ventilation to Meet ASHRAE Standard By Klas C. Haglid, P.E., R.A., CEM 1.
Important variables Water: Air: Conversion:
Announcements Midterm Project Prepare groups of 3 to 4 students You can submit the list at the end of next class Midterm Exam 03/09/10 - In class Exam:
Improved Precision Leading to Improved Energy Efficiency Edward Decker AE 790 – Intelligent Buildings June 6, 2006.
VAV Box Control Loop The purpose of the VAV Box control loop is to adjust airflow through the box to maintain a space temperature. The difference between.
Objectives Discuss final project deliverables Control Terminology
Sizing Variable Flow Piping – An Opportunity for Reducing Energy
Control Theory Control System Objectives  Establish a final condition  Provide safe operation  Eliminate the human element  Assure economical operation.
Roof Top Unit Overview (MAGNUM) Visit us at Revision- 12/17/2015.
Objectives Finish DOAS Control Terminology Types of controllers
Introduction to Energy Management. Week/Lesson 13 Control Strategies for Occupant Comfort.
Learning Outcomes Upon completion of this training one should be able to: Identify hydronic chilled water system applications. Define the difference between.
Test and Balancing Functional Performance Test Presented by: John Shelander and Dan Acri.
RTF RTUG Update Aug 12, 2010 “The Turn of the Screw” Premium Ventilation Extended Monitoring Reid Hart, PE Associate Director Technical Research Group.
7/15/2002PP.AFD.09 1 of 43 Yaskawa Electric America Variable Frequency Drives In HVAC Applications.
Day 1 Part 4 Technician’s Guide & Workbook for Home Evaluation and Performance Improvement.
Announcements Next class is the course evaluation
WSHP Systems 1.
Maria’s Restaurant Chapter 2 Section 9
Part 16 Technician’s Guide & Workbook for Duct Diagnostics and Repair
Maria’s Restaurant Chapter 1 Section 4
Mark Hydeman, PE of Taylor Engineering
14 Refrigerant Recovery, Recycling, and Recharging.
HYDRONIC HVAC: The Most Comfortable and Efficient System
Maria’s Restaurant Chapter 3 Section 13
HYDRONIC HVAC: The Most Comfortable and Efficient System
Roof Top Unit Overview (MAGNUM)
Engineering Presentation
HCB 3-Chap 19A: All-Air Systems_Single Zone
High Performance HVAC Installation
Flip The Long House Let’s imagine the Long house example in Manual J has undergone a house flipping/energy savings update. The insulation was increased,
Lecture Objectives: Discuss Projects 1 and 2
Manual D Duct Sizes Room Cooling CFM % Total CFM Heating CFM Kitchen GR Dining Bed Bed 3.
Maria’s Restaurant Chapter 2 Section 9
Chapter 3B: INDOOR AIR QUALITY
Presentation transcript:

Presented by: name title date 2008 Title 24 Nonresidential HVAC Acceptance Testing for Building Officials & Contractors Presented by: name title date California Commissioning Collaborative

What this talk will cover Description of acceptance testing requirements in 2008 Title 24 The motivation behind the requirements How acceptance testing affects design and specification practices How it impacts compliance documentation New responsibilities of the designer and the contractor Impacts on plan review and inspection

Overview Building Efficiency a product of: Traditional standards Materials and equipment Installation and set-up Occupant patterns and control Traditional standards Specify materials, equipment, controls Law of diminishing returns for more efficient equipment 2008 Title 24 standards – Acceptance Tests Ensure equipment works as intended

What is acceptance testing? Two components of acceptance testing Construction inspection Is the specified equipment installed and calibrated? Functional performance testing Does the equipment work as intended? Tests designed to uncover specification, installation or set-up problems Not replacing commissioning Commissioning = broader scope

Is acceptance testing needed? PIER Small Commercial HVAC survey* Small commercial buildings < 4 yrs old 64% of economizers failed Cooling energy increased by 37% 38% of supply fans cycling during occupancy Violation of Title 24 30% unoccupied fan operation Increase of fan and heating energy 8% no outside air 8% simultaneous heating and cooling * http://www.energy.ca.gov/reports/2003-11-17_500-03-082.PDF

Who benefits from acceptance tests? The designer System installed and controlled according to code design intent Reputation based on correct equipment operation The contractor Technician’s work is reviewed Fewer call-backs The owner Equipment works right the first time Energy cost savings Society Less pollution associated with reduced energy consumption

Acceptance Tests Required self-certification that equipment and systems were tested and work as intended Requires someone with a license to sign off on the testing (architect, engineer or contractor) Only one test (air distribution efficiency) requires 3d party verification Home Energy Rating Service (HERS)

Resources 2008 Standards (Title 24) 2008 Standards Nonresidential Appendices NA 7 Reference – not needed for design or testing 2008 Nonresidential Energy Standards Compliance Manual Chapter 4 – Mechanical Systems Chapter 10 – Acceptance Requirements End of Manual – Compliance and Acceptance Forms CEC Resources http://www.energy.ca.gov/title24/2008standards/ CEC Bldg Standards Hotline 1-800-772-3300

Acceptance Chapter in Nonresidential Manual Overview of compliance process At-A-Glance – 2 page overview of test Purpose  Estimated Time Benefits  Warnings or Cautions Instrumentation  Test conditions Acceptance Criteria Detailed test description

Acceptance and Compliance Forms Filled out by designer MECH-1-C (C for compliance) Reviewed by plans checker Acceptance Forms Filled out by person conducting test Reviewed by person with a license Usually contractor, TAB or commissioning agent MECH-1-A to MECH (A for acceptance) Collected by Inspector prior to CO (Certificate of Occupancy) Forms in Appendix A of the Nonresidential Compliance Manual

Code Enforcement Process: Plans and Specifications Compliance documentation with equipment specification and forms MECH-1C lists all tests and which equipment must be tested MECH-3C lists design minimum outside air Criteria for outside air tests (NJ.3.1 & 3.2) Plan checker reviews and approves or asks for modifications All AC systems should be listed with appropraite tests

Code Enforcement Process: Testing and Inspection Installing contractor or other “eligible professional” conducts tests and fills out MECH-#A acceptance forms Equipment fixed until it passes all tests Completed forms handed to inspector along with other documentation Inspector makes sure documentation is filled out correctly Incomplete documentation is returned to contractor Certificate of Occupancy granted when building is in full compliance

Designer has a big impact on ease and cost of acceptance tests Designer clearly identifies tests Problem if covered equipment not specified on MECH-1C form and later needs testing Designer specifies equipment Pre-calibrated equipment is cheaper Designer builds in test capabilities Test ports and pre-installed gauges Valves for isolating equipment

Key Statements in MECH-1C The plans meet code I am qualified to sign these forms List of all mechanical acceptance tests with blanks for: Equipment to be tested Checkboxes to indicate which tests apply to the equipment listed

Defined in Standards’ Mandatory Section 125 HVAC Acceptance Tests Defined in Standards’ Mandatory Section 125 Detailed in the Appendix NA7 Nonresidential Compliance Manual Test Descriptions in Chapter 10 Forms in Appendix A 15

Acceptance Requirements (1 of 2) ACM Section and Test Standard Section Additional Standard Section Certificate of Acceptance NA 7.5.1.1 Variable Air Volume Systems Outdoor Air 125(a)1 121 MECH-2A NA 7.5.1.2 Constant Volume Systems Outdoor Air NA 7.5.2 Constant Volume Packaged HVAC Systems 125(a)2 122 MECH-3A NA 7.5.3 Air Distribution 125(a)3 124, 144(k) or 149(b)1D MECH-4A NA 7.5.4 (Air-Side) Economizer 125(a)4 144(e) MECH-5A NA 7.5.5 Demand Control Ventilation 125(a)5 121(c)3&4 MECH-6A NA 7.5.6 Supply Fan Variable Flow Controls 125(a)6 144(c)2 MECH-7A NA 7.5.7 Valve Leakage Test 125(a)7 & 8 144(j)2 or 3 MECH-8A NA 7.5.8 Supply Water Temperature Reset Controls 125(a)9 144(j)4 MECH-9A NA 7.5.9 Hydronic System Variable Flow Controls 125(a)7 144(j)6 MECH-10A NA 7.5.10 Automatic Demand Shed Controls 125(a)10 122(h) MECH-11A Updated for 2008 16

New Acceptance Requirements (2 of 2) for Compliance Credit Measures ACM Section and Test Standard Section Additional Standard Section Certificate of Acceptance NA 7.5.1.11 FDD for Packaged DX Systems 125(a)11 MECH-12A NA 7.5.1.12 FDD for AHUS and Zone Terminal Units 125(a)12 MECH-13A NA 7.5.1.13 Distributed Energy Storage DX AC Systems 125(a)13 MECH-14A NA 7.5.1.14 Thermal Energy Storage Systems 125(a)14 MECH-15A 17

Acceptance Tests Always Applied to Single Zone Rooftop Units MECH-2A - Outdoor Air for CAV Measured outside air within 10% of the values listed on MECH-3C MECH-3A - Constant Volume & Single-Zone Unitary Verifies that sequence of operation is correct Setup and setback works Fan turns off – unoccupied period When fan off – O/A damper closed No simultaneous heating and cooling

Acceptance Tests - Single Zone Rooftop Units – sometimes in order of likelihood MECH-5A - Economizer Controls Only if the unit has an economizer MECH-6A - Demand Control Ventilation Required for high density applications Retail (first floor) Auditoriums Schools are specifically exempt MECH-4A - Air Distribution Ducts Duct leakage test Only if > 25% of duct surface area outdoors or in ventilated attic (not plenum) Change-outs ducts not inc conditioned space

Acceptance Tests Always Applied to Variable Air Volume Systems MECH-2A - Outdoor Air for VAV Measured outside air within 10% of the values listed on MECH-3C at high and low flowrate MECH-7A Supply Fan VAV Fan slows down at lower loads For DDC to zone, duct pressure drops MECH-5A - Economizer Controls Systems over > 75,000 Btu/h required to have an economizer

Direct Digital Control to the Zone System has a central automated control that receives feedback from all zones Allows pressure reset of variable flow fans or pumps Pressure dropped until most open damper or coil valve is almost full open. Thus all zones have enough pressure. Allows resetting of zone temperature in response to a utility signal (demand response) Allows adjusting outside air in response to CO2 level in zones

Acceptance Tests Frequently Applied to VAV Systems with DDC to the Zone MECH-11A Automatic Demand Shed Control Setup in response to utility signal MECH-6A Demand Control Ventilation Required for high density applications Retail (first floor) Auditoriums Exempted: Schools, healthcare, social service

Acceptance Tests Usually Applied to Hydronic Systems MECH-8A - Valve Leakage Test Check isolation valves on boilers and chillers Test all valves on rest of system MECH-10A - Hydronic System Variable Flow Control Under low coil load, fan speed drops Under low coil load, system that is DDC to zone, pressure drops MECH-9A - Supply Water Temp. Reset Reset required only for systems > 500,000 Btu/h. If system has controls, test required

Compliance forms end in “–C” 24

          5 CV RTU 1 to 5 VAV AHU 1 & 2 2 1 CHW System Checks in red indicate tests that would always be done for these system types 25

What is an acceptable package of acceptance tests All Acceptance Tests listed on MECH-1C are completed All signature blocks legible and signed All values filled in & specific to equipment Identical values for all tests indicate tests not being conducted All tests should be “Passed”

T24 2008 HVAC Forms Changes in 2008 Revisions to MECH-1C Certificate of Compliance New Field Inspection Checklist New Installation Certificate (10-103(a)3A) Reorganized Acceptance Test Forms (Certificates of Acceptance) 27

The not so fine print Systems Acceptance. Before occupancy permit is granted … … all control devices shall be certified as meeting the Acceptance Requirements Systems Acceptance. Before occupancy permit is granted. All newly installed HVAC equipment must be tested using the Acceptance Requirements. The MECH-1C form is not completed and is not to be accepted by the building department unless the correct boxes are checked. The building inspector must receive the properly filled out and signed forms before the building can receive final occupancy. Do you see a pattern??

New Field Inspection Checklist Filled out by designer or Title 24 documentation author (or automatically by compliance software) Used by field inspector to help identify critical components Title 24 2008

Installation Certificate Completed by licensed person responsible for building construction or installation of the mechanical system Certifies that installed system meets code requirements There is no longer a MECH 1A Form! Title 24 2008

Project information (typical) Acceptance forms end in “-#A” Technician block (typical) Reviewer block (typical) 31

People Qualified to Certify Tests “Responsible Person” California licensed engineer, or architect Eligible under Division 3 of the Business & Professions Code ... to take responsibility for the scope of work Mechanical and civil engineers California licensed contractor

California Contractors typically eligible to take responsibility for acceptance tests A General Engineering Contractor B General Building Contractor C-4 Boiler, Hot Water Heating System Fitting Contractor C-20 Warm-air Heating, Ventilation & Air Conditioning Contractor C-36 Plumbing Contractor C-38 Refrigeration Contractor C-43 Sheet Metal Contractor D-62 Air and Water Balancing C-10 Electrical Contractor (controls) C-7 Low Voltage Systems Contractor (controls) Other contractors with related classifications

Construction inspection (typical) Functional Testing block (typical) 34

Test summary (Typical) 35

Completed acceptance tests are a condition of the Certificate of Occupancy Late installation of a given piece of equipment is no excuse All other equipment can be tested and a conditional permit granted for the late piece of equipment

Simple Spot Tests – Summer Economizer Have contractor place all AC in cooling mode in early morning All economizers should be open Have contractor place in heating mode All economizers should be closed Have contractor place systems back in cooling mode All economizers should close when it is hot out

Simple spot tests VAV system – summer Have contractor set cooling setpoint low Fan speed should increase – listen or look at VFD output Have contractor set cooling setpoint high Fan speed should decrease

Minimum Outdoor Ventilation Air Acceptance MECH-2A Appendix NA 7.5.1 39

Why is minimum outside air important Too little O/A – sick building syndrome Often too little O/A at low flow for VAV systems Too much O/A – huge energy penalty Hot summer day - 3 tons extra cooling for each 1,000 cfm excess outside air. Without adjusted O/A – easily 100% excess outside air

Outside air dampers When in heating mode or in cooling mode where bringing outside air would increase load on building… ….outside air dampers are set or controlled to allow the minimum outside air needed to protect health and dispel normal odors.

Purpose of Outdoor Air Acc. Test Verification of minimum OutSide Air (OSA) as scheduled on plans Verification that minimum OSA is provided throughout the range of operation in a VAV system and at design for CV systems Measured CFM of minimum outside air at min flow and full flow must be within 10% of design CFM on MECH-3C 42

Design Minimum Outside Air MECH-3C VAV-O = office space, VAV-A = assembly space, Min O/A in Column I VAV-O 1,000 0.15 150 5 75 150 160 350 400 400 300 N/A VAV-A 1,000 0.15 150 34 510 510 510 1,200 400 1,200 550 N/A Totals 39 660 670 0 Min O/A for MECH-2A 67 x 0.5 = 34

Signal from SAT Controller Fixed Minimum OA Damper Position only allowed for constant volume systems For VAV systems does NOT WORK since mixed air plenum pressure varies!! Outdoor air flow will vary proportional to supply air flow Outdoor Air Intake Minimum Signal Pot. Return Air Signal from SAT Controller 44

Test Procedure CV System Disable economizer (if applicable) Disable DCV (if applicable) Measure and record OSA Restore boxes, economizer and DCV controls Setup Test Clean up 45

How to Disable an Economizer Drop high-limit control setpoint below current OA temperature or enthalpy (all controls), or Raise OA temperature or enthalpy reading above high limit control setpoint (DDC controls), or Disable economizer control block (DDC controls) 46

How to Disable and Engage DCV Controls Disable DCV Raise CO2 setpoint significantly above current CO2 reading (all controls) Engage DCV Lower CO2 setpoint to lowest possible setpoint (all controls) 47

How to Measure OSA AFMS (air flow monitoring station) If part of the system Calibrated damper (if part of the system) Traverse of OSA louver/duct Traverse of SA and RA ducts (differential) For each test OSA must be +/-10% of design Note: on small packaged units you might have to provide a temporary sheet metal hood on the OSA intake to get a good reading 48

Construction Inspection Calibration of AFMS or calibrated damper (if part of the system) Verify that there is a provision for dynamic control of OSA (if VAV) Verify that there is a provision for minimum OSA (if CV) 49

VAV Acceptable O/A Control Dual Minimum Minimum damper position is set proportionally based on fan speed between setpoints determined when the fan is at full speed and minimum speed Low cost Affected by wind, stack effect, filter loading 50

Example Method of Dynamic OSA Control: Injection Fan Outdoor Air Intake Return Air Injection Fan w/ Discharge Damper Signal from SAT Controller 51

Example Method of Dynamic OSA Control: Fixed Damper with DP control ∆P correlated to flow for fixed orifice Can be 1 section or entire OA damper Outdoor Air Intake Return Air Signal from SAT Controller 52

Test Procedure VAV System Disable economizer (if applicable) Disable DCV (if applicable) Drive all boxes to minimum airflow Measure and record OSA Drive all boxes to design airflow Restore boxes, economizer and DCV controls System passes if measured OSA in steps 4 & 6 are within 10% of design OSA Combine tests to save time and $$ MECH-2A full airflow test with DCV disabled MECH-6A. full airflow test with DCV enabled Setup Test 1 Test 2 Clean up 53

How to Drive VAV Boxes Open Set zone cooling temperature setpoint below the current zone temperature (all controls) Override the VAV box airflow setpoint (DDC controls) With DDC controls you might want to specify preset functions to drive all boxes to design airflow and minimum airflow to speed up the tests Note: if you override the VAV box damper you may provide more than the design maximum airflow 54

How to Drive System to Minimum Airflow Set zone cooling temperature setpoint above the current zone temperature (all controls) Override the VAV box control airflow setpoint (DDC controls, could be preset) Manually slow down fan until airflow is ~30% of design airflow (all controls, requires AFMS or duct traverse) 55

Project information (typical) Technician block (typical) Reviewer block (typical)

Construction inspection (typical)      Testing block (typical)  Project XYC, Somewhere, California AH 1 2nd Floor Offices Construction inspection (typical)     1,850 2,000 3 mins  Testing block (typical) 1,910 2,000 3.2 mins  92.5 95.5 Title 24 2008

Project XYC, Somewhere, California AH 1 2nd Floor Offices Test summary (Typical) 

Reasons to Reject the MECH-2A Signatures or names are missing for technician or reviewer Ratio of measured flowrate to design outside air flow rate (Percent OSA) >110% <90% Suspicious if all tests: Measured airflow equal to design airflow rate

Packaged HVAC Controls MECH-3A 60

Check thermostat, setpoints and scheduling controls Purpose Check thermostat, setpoints and scheduling controls Verify that heating, economizer and cooling are properly sequenced Verify operation in occupied and unoccupied modes 61

62

MECH-3A Functional Tests Simulate various operating modes Heating load occupied, no-load occupied, heating load unoccupied, no load unoccupied, etc. Each condition is a column on the table Check for various HVAC unit responses Different responses represented by each row Areas grayed out are incorrect responses Areas with check boxes are correct responses Test and fix until under each operating mode only responses are those indicated by check box

64

Occupied Mode Test Procedure Heating Supply fan operates continuously OSA is provided No cooling occurs Verify that all heating stages work Dead Band No heating or cooling occurs Cooling No heating occurs Verify that all cooling stages work Note the cooling test is repeated under economizer acceptance 65

How to drive the unit into heating, cooling or deadband Move thermostat cooling setpoint below the current room temperature Dead Band Move the thermostat cooling setpoint above the current room temperature, and Move the thermostat heating setpoint below the current room temperature Heating Move the thermostat heating setpoint above the current room temperature 66

Unoccupied Mode Test Procedure Heating Supply fan cycles on with call for heating (and off when satisfied) OSA is closed or cycles with supply fan No cooling occurs Dead Band Supply fan is off OSA damper is closed No heating or cooling occurs Cooling No heating occurs Again, the cooling test is repeated under economizer acceptance 67

How to move the unit into “unoccupied” mode Adjust the schedule so that the unit is scheduled off at the current time, or Reset the current time so that it is outside of the scheduled occupied period 68

Override Mode Test Procedure Enable after hours override System goes to “occupied” mode System returns to “unoccupied” mode after timed delay Return system to normal operation Reset all setpoints Remove any jumpers 69

How to activate the after-hours override Put the unit into “unoccupied” mode (see previous slide) Push the after-hours button on the thermostat 70

Air-Side Economizer MECH-5A 71

Check economizer installation and provision for exhaust or relief Purpose Check economizer installation and provision for exhaust or relief Test economizer operation When a call for cooling and it is cool outside the economizer brings in outside air Other times min O/A 72

Overview References Scope Standard Sections §144(e) and §125(a)4 Form MECH-5A Non-Residential Appendix NA 7.5.4 Nonresidential Compliance Manual 10.6.10 Scope All new systems with air-side economizers No functional testing required if economizer is factory installed and certified operational None certified currently 73

74

High Limit Switch 75

Economizer Functional Testing Step 1: Disable demand control ventilation (DCV) systems (if applicable) Step 2: Enable the economizer and simulate a cooling demand Economizer damper is 100 percent open and return air damper is 100 percent closed. For systems > 75,000 Btu/h economizer is integrated 100 % open when the cooling demand can no longer be met by the economizer alone. All applicable fans and dampers operate as intended to maintain building pressure. The unit heating is disabled. Step 3: Disable the economizer and simulate a cooling demand. Economizer damper closes to its minimum position. The unit heating is disabled Step 4: Simulate a heating demand and set the economizer so that it is capable of operating (i.e. actual outdoor air conditions are below lockout setpoint). The economizer is at minimum position Step 5: Restore DCV systems and remove all system overrides

How to Disable an Economizer Drop high-limit control setpoint below current OA temperature or enthalpy (all controls), or Raise OA temperature or enthalpy reading above high limit control setpoint (DDC controls), or Disable economizer control block (DDC controls) Do the opposite to enable economizer 77 77

78

VAV Supply Air Acceptance Test MECH-7A Drawing courtesy of Steven Taylor 79 79

Check calibration and setpoint of pressure sensor for VAV systems Purpose Check calibration and setpoint of pressure sensor for VAV systems Check stability of control on VAV systems at full and part load Make sure fan speed slows with reduced load, supply air pressure does not rise For DDC to zone system, system air pressure drops at reduced load 80 80

Overview References Scope Standard Sections §144(c)2B, C & D and §125(a)6 Non-Residential Appendix 7.5.6 Nonresidential Compliance Manual 10.6.14 Scope New VAV fans greater than or equal to 10 hp Both prescriptive and performance approach 81 81

Construction Inspection - Verify Discharge static pressure sensors are either factory calibrated or field-calibrated. The static pressure location, setpoint, and reset control meets the requirements of §144(c)2C and §144(c)2D. Sensor Location so set point < 1/3 the total design static P (i.e. near the end of the duct) except for DDC to zone systems w/ pressure reset If located below major duct splits, sensors in each major branch, take lowest value for control DDC to Zone, Set Point Reset. pressure set point based on the zone w/ most need zone damper needing most pressure is nearly wide open. 82 82

Construction Inspection 83 83

Test Procedure You may have to disable SA temperature reset during this test to prevent unwanted flow fluctuations Drive boxes to achieve design airflow (refer to min OSA test for how to do this) Record measured SP (must be +/- 10% of setpoint) Note if fan speed stabilizes within 5 minutes 84 84

Test Procedure Drive boxes to achieve minimum airflow (refer to min OSA test for how to do this) Record measured duct static pressure (must be +/- 10% of setpoint) For DDC to zone systems, pressure setpoint must be reduced Note if fan speed stabilizes within 5 minutes 85 85

Functional Performance Testing 86 86

Demand Control Ventilation (DCV) MECH-6A 87 87

Demand Control Ventilation Requirements (§121(c)4) Where DCV is applied, it must meet the following: One sensor for each space that meets the criteria of 121(c)3B Sensor must be CO2 Sensor must be located in the breathing zone between 3’ and 6’ AFF or at the anticipated level of the occupant’s heads Maintain setpoint of 600ppm + OSA ppm 400 PPM default or dynamically measured No greater than design ventilation @ 15 cfm/person No less than ventilation from Table 121-A (cfm/ft2) Design ventilation for spaces without DCV 88 88

Do Return CO2 Sensors Work? Return is diluted by other Zones and does not track the critical zone No. Separate sensors are needed in each high density space 89 89

Check DCV calibration and installation Test DCV at: Purpose Check DCV calibration and installation Test DCV at: High CO2 levels Low CO2 levels 90 90

NA 7.5.1 Outdoor Air Acceptance Related Tests NA 7.5.1 Outdoor Air Acceptance NA 7.5.4 (Air-Side) Economizer Acceptance This test should be combined with minimum OSA and economizer acceptance tests to reduce time and costs 91 91

92 92

DCV Test Procedure Disable economizer controls Measure CO2 concentration If dynamic control < 600 ppm above ambient concentration Default ambient concentration 400 ppm, indoor air < 1,000 ppm Step 1:Simulate a signal at or slightly above the CO2 concentration setpoint required by §121(c)4C. Verify and document the following: For single zone units, outdoor air damper modulates open to satisfy the total ventilation air called for in the Certificate of Compliance. For multiple zone units, either outdoor air damper or zone damper modulate open to satisfy the zone ventilation requirements. Not required to have cfm greater than MECH-3C column I (design ventilation air cfm) Step 2: Simulate signal well below the CO2 setpoint. Verify : For single zone units, outdoor air damper modulates to the design minimum value. For multiple zone units, either outdoor air damper or zone damper modulate less open to satisfy the reduced zone ventilation requirements. CFM must be at least as much as MECH-3C Column D (Min CFM by Area) for DCV controlled zone + MECH-3C column I (design ventilation air cfm) for uncontrolled zones Step 3: Restore economizer controls and remove all system overrides initiated during the test. 93 93

Overriding CO2 Controls To simulate high demand you need to decrease the sensor setpoint To simulate low demand you need to increase the sensor setpoint Best accuracy results from using calibrated gas 94 94

Default is 400 ppm 95 95

Duct Sealing Air Distribution Systems MECH-4A 96

MECH-4-A Air Distribution §144(k) Small (<5,000 sf) CV systems only When > 25% of duct surface is outdoors or in unconditioned space Place greater than 75% of ducts under insulated roof – test not needed Ducts must be tested for duct leakage …. and verified as sealed by a HERS rater

MECH-4-A Construction Inspection Drawbands Stainless steel worm drive or UV resistant nylon duct ties Duct leakage tests performed before access is blocked Duct tape not used unless with drawbands and mastic R-8 insulation Outdoor insulation protected from damage

99

MECH-4A Calculated supply fan flow Rated flow from capacity 400 cfm/ton 21.7 cfm/kBtuh heating only systems 100

MECH4-A Leakage Test New Construction Seal all diffusers Pressurize system to 25 Pa (0.1 in WC) with fan with calibrated orifice (duct blaster) Measured leakage no greater than 6% of rated flow Likely conducted by HVAC contractor Verified by HERS rater

MECH-4-A Duct testing

MECH-4A Duct Testing Results New Construction or Alterations 103 103

MECH-4-A Duct Sealing on Retrofits §144(k), 149(b)1D&E Applies to small CV system with ducts outside or in unconditioned spaces when: Ducts replaced HVAC system is replaced or major repair (new compressor, new coil etc.) Existing duct leakage ≤15% of rated supply flow >60% reduction of leakage prior to sealing ducts with all visible leaks sealed Can’t get at the ducts and all visible leaks are sealed as certified by a HERS rater Exceptions Asbestos Existing ducts that were previously certified 104

HERS Rater Sampling Test Validation All systems must best tested by person conducting acceptance tests Independent HERS rater verifies results through sampled re-testing of systems: Verify the first system tested Verify one out of the each group of 7 tested If that unit fails the test, test a second unit in the group of 7 if that fails test the other 5 in the group of 7 Certify ALL of the tests made by the contractor Enter all tests into the HERS database New groups of 7 applies to each new construction project (but not for retrofit) 105 105

Automatic Demand Shed Controls 106

Automatic Demand Shed Controls (122(h)) All New! For systems with DDC to the zone: Ability to reset thermostat setpoint up to 4°F on all “non-critical” zones through real or virtual DI. System needs an adjustable rate of change for reset Shown by LBNL and Purdue to reduce on-peak demand by over 30%. Supported by ASHRAE Standard 55 (Table 5.2.5.2). 107

Overview References Scope Standard Sections §122(b)4, §122(h) and §125(a)10 Non-Residential Appendix NA 7.5.10 Nonresidential Compliance Manual 10.6.19 Scope New DDC Zone Controls 108

Purpose To make sure that the demand shed controls are programmed and work when engaged Demand shed controls gives the owner the opportunity to temporarily turn up t-stats in all non-critical areas 4F a few hours per year. Utility financial incentives Less likely to have a black-out 109

Automatic demand shed controls NA7.5.10.1 Construction Inspection Prior to Acceptance Testing, verify and document the following: That the EMCS interface enables activation of the central demand shed controls. NA7.5.10.2 Functional Testing Step 1: Engage the global demand shed system. Verify : Cooling setpoint in non-critical spaces increases by the proper amount. Cooling setpoints in critical spaces do not change. Step 2: Disengage the global demand shed system. Verify : Cooling setpoint in non-critical spaces return to their original values. Cooling setpoint in critical spaces do not change. 110

111

112

Beyond Scope for Today ACM Section and Test Standard Section NA 7.5.1.11 FDD for Packaged DX Systems 125(a)11 NA 7.5.1.12 FDD for AHUS and Zone Terminal Units 125(a)12 NA 7.5.1.13 Distributed Energy Storage DX AC Systems 125(a)13 NA 7.5.1.14 Thermal Energy Storage Systems 125(a)14 These tests are documented in the Non-Residential Appendices and Non-Residential Compliance Manual. They are only required when you seek a compliance credit. 113

Summary Acceptance tests assure that design intent for energy savings is executed All heating and cooling systems have at least one associated acceptance test The designer identifies which tests get applied to which equipment on the MECH-1-C form Plans examiner reviews MECH-1C form to assure all equipment has applicable tests specified Compliance forms are rejected and returned to applicant if all applicable HVAC systems and tests are not called out Fully COMPLETED acceptance test forms with all systems PASSING must be given to inspector before building receives Certificate of Occupancy. Schedule a challenge test if results are suspicious

Sample Questions Which compliance form lists all acceptance tests that must be conducted? Who can be a “responsible person” for the acceptance tests? Are acceptance tests a requirement for a certificate of occupancy? Which acceptance test requires a third party HERS verification? Are any tests valid without 3d party verification? What is done if a system does not pass an acceptance test?

More questions What tests are always required on constant air volume systems? What tests are always required of VAV? What tests are usually required of VAV systems with DDC to the zone?

Outdoor Air Acceptance Test Questions Which compliance form contains the design ventilation air information? Measured ventilation air cfm must be within what percentage of design ventilation air cfm? 5%, b) 10%, c) 30%, d)50% For VAV, variable air volume, systems outside air must be measured at design (full) flow and at what other supply air flowrate?

Packaged A/C Acceptance Test Questions Select all true answers below When is supply fan on during occupied hrs: a) Heating call, b) Cooling call, c) No call for either heating or cooling When is supply fan on during unoccupied hrs: Heating call, b) Cooling call, c) No call for either heating or cooling When is the outside air damper completely closed?

Air-side Economizer Test Questions True or False Economizer open when call for cooling and outside air temp is below high limit setpoint Economizer is open when call for heating and outside air temp is below high limit setpoint Economizer closed when call for cooling and outside air temp is above high limit setpoint Construction inspection not required for factory installed economizer w/ CEC certification.

Energy Efficiency Hotline Resources – 2008 Standard Energy Efficiency Hotline E-mail: title24@energy.state.ca.us Phone: 916-654-5106 or Phone: 1-800-772-3300 (toll free in Calif.)

California Commissioning Collaborative Pacific Gas & Electric Company Acknowledgements California Commissioning Collaborative Pacific Gas & Electric Company Codes & Standards Program California Energy Commission Tav Commins, Project Manager Mark Hydeman, Taylor Engineering Jon McHugh, McHugh Energy Consultants