Attachment 02.pdf

ACR The NADCA Standard • 2021 Edition 1

ACR

The NADCA Standard for Assessment, Cleaning, and Restoration of HVAC Systems

2021 Edition The International Standard Developed by the

National Air Duct Cleaners Association (NADCA)

ACR-2021 Committee Roster Bill Lundquist, ASCS, CVC, Co-Chair . . . . . . . . . . . . . . . . . . . . . . . . Eagle River Service Company (Eagle, CO) April Yungen, ASCS, CVI, Co-Chair . . . . . . . . . . . . . . . . . . . . . . . . . Air Management Industries (Rancho Cucamonga, CA) Richard Lantz, ASCS, CVI, Immediate Past Chair . . . . . . . . . . . . Virginia Air Duct Cleaners, Inc . (Chesapeake, VA) Andrea Casa, ASCS, CVI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALISEA S .R .L . (Pavia, IT) Jim Castellano, ASCS, CVI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Better Air Quality (Middle Island, NY) Charlie Cochrane, ASCS, CVI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cochrane Ventilation, Inc . (Wilmington, MA) Paul Keller, Jr ., ASCS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Service-Tech Corporation (Clearwater, FL) Greg Long, ASCS, CIEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IAQ Consulting LLC (Salado, TX) Rick MacDonald, ASCS, CVI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Armstrong Duct, Vent, Hearth & Home (Manchester, NH) Michael McDavid, ASCS, CVI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Professional Abatement & Remediation Technologies (Fenton, MO) Patrick O’Donnell, ASCS, CVC, CIEC . . . . . . . . . . . . . . . . . . . . . . . . Enviro Team North America (Ft . Lauderdale, FL)

Technical Editors Jodi Araujo, CEM Kristy Cohen

Project Management Association Headquarters, Mt . Laurel, NJ

Published by National Air Duct Cleaners Association (NADCA) 1120 Rt . 73, Suite 200 Mt . Laurel, NJ 08054 Toll Free: (855) GO-NADCA | P: (856) 380-6810 | F: (856) 439-0525

Copyright @ 2021 by NADCA All rights reserved .

No part of this publication may be reproduced in any form – mechanical, electronic or otherwise – without prior express written consent of the publisher . Printed in the United States of America .

ACR The NADCA Standard • 2021 Edition2

DISCLAIMER

The National Air Duct Cleaners Association (NADCA) has developed and published the Assessment, Cleaning, and Restoration of HVAC Systems (“ACR, The NADCA Standard – 2021 Edition” or the “Standard”) . The Standard is intended to provide information for assessing new and existing HVAC systems, evaluating the cleanliness of HVAC system components, and guiding the cleaning and restoration of HVAC systems to a specific level of cleanliness . The Standard is also intended to assist individuals and entities in establishing and maintaining their professional competence while working in the duct cleaning industry . All persons using the Standard must be, and remain, updated and informed about developments in the duct cleaning industry so that he/she may implement changes in technology and procedures as appropriate, as well as adhere to all applicable federal, state, provincial, and local laws and regulations . Since every cleaning and restoration project is unique, in certain circumstances, common sense, experience, and professional judgment may justify a deviation from the information provided in the Standard . Furthermore, this Standard is not intended to be either exhaustive or inclusive of all pertinent requirements, methods, systems, or procedures that might be appropriate on a particular job . The information upon which this Standard is based is subject to change, which may modify, supplement or invalidate any or all of the information contained herein .

ALL PERSONS USING THE STANDARD, AS A CONDITION OF USE, AGREES THAT NEITHER NADCA, NOR ANY ACR, THE NADCA STANDARD – 2021 EDITION COMMITTEE MEMBER OR CONTRIBUTOR SHALL BE LIABLE FOR ANY DAMAGES OF ANY NATURE WHATSOEVER, INCLUDING WITHOUT LIMITATION, ANY AND ALL SPECIAL, INCIDENTAL, COMPENSATORY, CONSEQUENTIAL, PUNITIVE, OR OTHER DAMAGES (INCLUDING DAMAGES FOR PERSONAL INJURY OR BODILY INJURY, PROPERTY DAMAGE, LOSS OF BUSINESS, LOSS OF PROFITS, LITIGATION, OR THE LIKE), WHETHER BASED UPON BREACH OF CONTRACT, BREACH OF WARRANTY, TORT (INCLUDING NEGLIGENCE AND GROSS NEGLIGENCE), PRODUCT LIABILITY, OR OTHERWISE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, WHETHER DIRECT OR INDIRECT, ARISING FROM OR RELATING TO THE PUBLICATION, USE OF, OR RELIANCE UPON, THE INFORMATION CONTAINED IN THIS STANDARD . THE FOREGOING LIMITATION AND NEGATION OF DAMAGES IS A FUNDAMENTAL CONDITION OF THE USE OF THE INFORMATION CONTAINED IN THIS STANDARD AND THIS

DOCUMENT WOULD NOT BE PUBLISHED WITHOUT SUCH LIMITATIONS .

While the information contained within this Standard is provided in good faith and is believed to be reliable, NADCA makes no representations, warranties, or guarantees as to the accuracy or completeness of any information contained in this Standard, or that following this Standard will result in compliance with any applicable laws, rules, or regulations; or will result in the safe, satisfactory, or complete performance of a duct cleaning project . NADCA does not warrant, assure, certify or guarantee that adherence to this Standard will result in any energy savings or correct any indoor air quality related concerns . Any instruction or directive issued by a governmental or regulatory “Authorities Having Jurisdiction” with respect to the assessment and/or remediation of mold shall supersede any contradictory information included in the Standard .

ALL PERSONS USING THE STANDARD, AS A CONDITION OF USE, AGREE THAT ALL WARRANTIES, EXPRESS OR IMPLIED, ARE DISCLAIMED BY NADCA (and its committee members and contributors), INCLUDING WITHOUT LIMITATION, ANY AND ALL WARRANTIES CONCERNING THE ACCURACY OR COMPLETENESS OF THE INFORMATION, ITS FITNESS OR APPROPRIATENESS FOR A PARTICULAR PURPOSE OR USE, ITS MERCHANTABILITY, ITS NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHTS, OR ANY OTHER EXPRESS OR IMPLIED WARRANTY WHICH MAY EXIST OR APPLY .

In publishing this document, NADCA is not undertaking to render scientific, professional, medical, legal, or other advice or services for, or on behalf of, any person or entity, or to perform any duty owed by any person or entity to others . Any and all use of or reliance upon this Standard is at the user’s own discretion and risk . All persons using the Standard should understand the limitations of the information provided in the Standard, and should rely on his or her own independent judgment, or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given situation .

ACR The NADCA Standard • 2021 Edition 3

Committee Roster - - - - - - - - - - - - - - - - - - - - - Page 1 Disclaimer - - - - - - - - - - - - - - - - - - - - - - - - - Page 2 Foreword - - - - - - - - - - - - - - - - - - - - - - - - - - Page 4 Purpose - - - - - - - - - - - - - - - - - - - - - - - - - - Page 5 Scope - - - - - - - - - - - - - - - - - - - - - - - - - - - - Page 5 Application - - - - - - - - - - - - - - - - - - - - - - - - - Page 5 Qualifications - - - - - - - - - - - - - - - - - - - - - - - Page 5 Limitations - - - - - - - - - - - - - - - - - - - - - - - - - Page 5 Determining the Need for HVAC Cleaning & Restoration - - - - - - - - - - - - - - - - - - - - - - - - - Page 6

Section 1 Inspections 1 .0 Overview - - - - - - - - - - - - - - - - - - - - - - - - Page 7 1 .1 When to Perform an Inspection - - - - - - - - - - - Page 7 1 .2 HVAC Inspector Qualification - - - - - - - - - - - - Page 7 1 .3 HVAC Pre-Inspection - - - - - - - - - - - - - - - - - Page 7 1 .4 Appropriate Environmental Engineering Controls - Page 7 1 .5 Routine HVAC Inspection - - - - - - - - - - - - - - - Page 7 1 .6 HVAC System Component Inspection-Construction, Retrofit, and Remodel - - - - - - - - - - - - - - - - - Page 7 1 .7 Performing HVAC System Component Inspections - - - - - - - - - - - - - - - - - - - - - - - Page 7 1 .8 Exposure to Hazardous Materials - - - - - - - - - - - Page 8 1 .9 Inspecting for Mold Contamination - - - - - - - - - Page 8 1 .10 System Component Assessment - - - - - - - - - - Page 8

Section 2 Work Plans 2 .0 Overview - - - - - - - - - - - - - - - - - - - - - - - - Page 9 2 .1 Purpose - - - - - - - - - - - - - - - - - - - - - - - - - Page 9 2 .2 Scope of Work - - - - - - - - - - - - - - - - - - - - - Page 9 2 .3 Means and Methods - - - - - - - - - - - - - - - - - - Page 9 2 .4 Other Trades and Their Tasks - - - - - - - - - - - - - Page 9 2 .5 Project Schedule - - - - - - - - - - - - - - - - - - - - Page 9 2 .6 Work Site Communication Plan - - - - - - - - - - - - Page 9 2 .7 Product Submittals - - - - - - - - - - - - - - - - - - Page 9 2 .8 Safety Plan & Safety Concerns - - - - - - - - - - - - Page 9

Section 3 Engineering Controls for HVAC Cleaning and Restoration Projects 3 .0 Overview - - - - - - - - - - - - - - - - - - - - - - - -Page 11 3 .1 Equipment Maintenance - - - - - - - - - - - - - - -Page 11 3 .2 Fuel-powered Equipment - - - - - - - - - - - - - - -Page 11 3 .3 Vacuum Equipment Exhausting Indoors - - - - - - -Page 11 3 .4 Negative Pressure Requirements - - - - - - - - - - -Page 11 3 .5 Handling of Contaminated Materials - - - - - - - - -Page 11 3 .6 Ambient Air Cleaning - - - - - - - - - - - - - - - - -Page 11 3 .7 Control of Product Emissions - - - - - - - - - - - - -Page 11 3 .8 Negative Pressure Failure - - - - - - - - - - - - - - -Page 11 3 .9 Level 1 Containment - - - - - - - - - - - - - - - - -Page 11 3 .10 Level 2 Containment (Temporary Barriers) - - - - -Page 12 3 .11 Level 3 Containment - - - - - - - - - - - - - - - -Page 12 3 .12 Level 4 Containment - - - - - - - - - - - - - - - - -Page 12 3 .13 Summary of Engineering Controls - - - - - - - - -Page 13

Section 4 Cleaning and Restoration Procedures 4 .0 Overview - - - - - - - - - - - - - - - - - - - - - - - Page 15 4 .1 Negative Duct Pressurization - - - - - - - - - - - - -Page 15 4 .2 Service Openings - - - - - - - - - - - - - - - - - - -Page 15 4 .3 Cleaning and Restoration of HVAC Systems - - - - -Page 15 4 .4 Wet Cleaning, Power Washing, and Steam Cleaning - - - - - - - - - - - - - - - - - - - - - - - -Page 15 4 .5 Vacuum Collection Equipment - - - - - - - - - - - -Page 16 4 .6 Air-Handling Unit (AHU) Cleaning - - - - - - - - - -Page 16 4 .7 Air Duct Cleaning - - - - - - - - - - - - - - - - - - -Page 16 4 .8 Dampers - - - - - - - - - - - - - - - - - - - - - - - -Page 16 4 .9 Registers, Grilles, Diffusers - - - - - - - - - - - - - -Page 16 4 .10 Smoke and/or Fire Detection Equipment - - - - -Page 16 4 .11 Coil Surface Cleaning - - - - - - - - - - - - - - - -Page 17 4 .12 Control of Odors and Product Emissions - - - - - -Page 17 4 .13 Remediation of Mold Contamination - - - - - - - -Page 17 4 .14 Restoration and Repair of Mechanical Systems - - - - - - - - - - - - - - - - - - - - - - - -Page 18 4 .15 Surface Treatments - - - - - - - - - - - - - - - - - -Page 18 4 .16 Removal of Mold Contaminated Porous Materials- - - - - - - - - - - - - - - - - - - - - - - -Page 18 4 .17 Cleaning Fibrous Glass Duct System Components - - - - - - - - - - - - - - - - - - - - -Page 18 4 .18 Resurfacing/Coating Fibrous Glass Surfaces - - - -Page 18 4 .19 Damaged Fibrous Glass Material - - - - - - - - - -Page 18 4 .20 Thermal-Acoustic HVAC Insulation Replacement - - - - - - - - - - - - - - - - - - - - -Page 18 4 .21 Non-Porous Material Restoration - - - - - - - - - -Page 18 4 .22 Flooding/Water Damage - - - - - - - - - - - - - -Page 19 4 .23 Fire/Smoke Damage - - - - - - - - - - - - - - - - -Page 19 4 .24 HVAC System Components Repair - - - - - - - - -Page 19

Section 5 Cleanliness Verification and Documentation 5 .0 Overview - - - - - - - - - - - - - - - - - - - - - - - -Page 21 5 .1 When to Perform Cleanliness Verification - - - - - -Page 21 5 .2 Description of Method 1-Visual Inspection - - - - -Page 21 5 .3 Description of Method 2 for Porous Surfaces – Surface Comparison Test - - - - - - - - - - - - - - -Page 21 5 .4 Description of Method 2 for Non-Porous Surfaces – NADCA Vacuum Test - - - - - - - - - - - - - - - - - -Page 21 5 .5 Passing Criteria for NADCA Vacuum Test - - - - - - -Page 22 5 .6 Post-Project Documentation - - - - - - - - - - - - -Page 22 Definitions - - - - - - - - - - - - - - - - - - - - - - - - -Page 23 Reference Documents and Resources - - - - - - - - - -Page 27 Acknowledgements - - - - - - - - - - - - - - - - - - - -Page 29 Form to Request Formal Interpretations - - - - - - - - -Page 31

ACR, The NADCA Standard - Table of Contents

ACR The NADCA Standard • 2021 Edition4

FOREWORD

Assessment, Cleaning, and Restoration of HVAC Systems (ACR, The NADCA Standard) is unique in that it is a performance standard that also provides minimum procedural requirements . This Standard has evolved from procedural-based guidelines, standards of care, and research originating from the National Air Duct Cleaners Association (NADCA), along with associated organizations . It is based on reliable principles, review of applicable industry literature and information, and practical experience .

This Standard establishes minimum performance requirements for assessing new and existing HVAC systems, evaluating the cleanliness of HVAC system components, determining the need to clean and cleaning and restoring systems to a verifiable cleanliness level . The Standard also focuses on preventing job-related hazards, such as exposure to workers and occupants, and cross-contamination to the indoor environment .

This document is written for use by those involved in the HVAC cleaning and restoration industry including specifiers, consultants, contractors and end users . Users of this document should stay updated and informed about changes in the industry and implement changes in technology and procedures, as appropriate, while following applicable federal, state, provincial, and local laws and regulations .

All HVAC cleaning and restoration projects are unique and, in certain circumstances, common sense, experience, and professional judgment may justify deviation from this Standard . It is the responsibility of the contractor, or others relying on this Standard, to verify on a case-by-case basis, that application of this Standard is appropriate . When in doubt, use caution and seek additional professional guidance . Users of this document assume all risks and liabilities resulting from use of, and reliance upon, this Standard .

ACR is a living document that is subject to change as more information regarding the HVAC cleaning and restoration industry becomes available and advancements are made in technology and practice . ACR, The NADCA Standard – 2021 Edition will be reviewed, evaluated, and validated through application in the field and thereafter revised and improved as deemed necessary .

ACR The NADCA Standard • 2021 Edition 5

GENERAL

PURPOSE

This Standard defines the minimum performance and procedural requirements for the assessment, cleaning and restoration of heating, ventilation and air conditioning (HVAC) system components . ACR, The NADCA Standard – 2021 Edition supersedes all previous editions of ACR, The NADCA Standard and is considered the standard of care for the HVAC cleaning and restoration industry .

SCOPE

This Standard applies to the assessment, cleaning and restoration of HVAC component airside surfaces as defined herein . It does not include the cleaning of non-ducted ceiling plenums and items such as the mechanical repair of electrical or pneumatic components of any kind, repair of high-pressure vessels, gas/oil controls or preventative maintenance tasks as prescribed by, or recommended by, the original equipment manufacturer (OEM) .

APPLICATION

ACR, The NADCA Standard – 2021 Edition provides minimum standards and guidance for industry professionals, HVAC assessment, cleaning, and restoration service providers, building owners, and others who manage HVAC systems and projects .

QUALIFICATIONS

Those responsible for performing work to this Standard shall be properly trained and qualified and possess relevant knowledge and experience before performing work of any type on HVAC Systems . It is recommended that an individual with an Air Systems Cleaning Specialist (ASCS) or equivalent certification, be responsible for oversight of the project .

LIMITATIONS

This Standard does not specifically address any and all hazards or risks that could be encountered when performing work in accordance with this document . Instead, the user is directed to rely on the Authority Having Jurisdiction in such cases .

ACR The NADCA Standard • 2021 Edition6

DETERMINING THE NEED FOR

HVAC CLEANING & RESTORATION

It is recommended that any HVAC system component or components be cleaned when a proper HVAC cleanliness inspection or building history indicates one or more of the following conditions exist:

• The HVAC system components are contaminated with an accumulation of particulate;

• The HVAC system components’ performance is compromised due to contamination build-up;

• The HVAC system components have been determined to be a source of unacceptable odors;

• The HVAC system components are discharging visible dirt or debris into the conditioned space;

• The HVAC system components have been contaminated as a result of fire, smoke, and/or water damage;

• The HVAC system components have been infested with birds, rodents, insects, or their byproducts;

• The HVAC system components have been determined to be at risk for fire hazard;

• The HVAC system components have become contaminated with construction particulate or debris;

• Mold contamination conditions have reached either Condition 2 or Condition 3;

• Deterioration of fibrous glass duct liner, duct board, or other porous components;

• As part of an HVAC maintenance program as defined in ANSI/ASHRAE/ACCA Standard 180;

• As part of the HVAC equipment manufacturers recommended maintenance practices;

• As part of a proactive energy management program;

• As part of a proactive indoor air quality management program;

• As a component to achieve LEED Certification;

• When a newly installed component or duct has been contaminated with construction and/or other dust and debris .

NOTE: If there is any question on the need to clean, the Method 2 for Porous Surfaces - NADCA Surface Comparison Test or Method 2 for Non-Porous Surfaces - NADCA Vacuum Test may be performed to determine the need for cleaning . These tests are described in detail in Section 5 of this Standard .

ACR The NADCA Standard • 2021 Edition 7

Section 1 – Inspections

1.0 Overview: Inspections are an important component of

any HVAC cleaning and restoration project . HVAC inspections shall be performed to determine the need for cleaning . HVAC inspections shall also be performed to determine the scope of work, engineering controls, safety measures and tools and equipment necessary to perform a cleaning and restoration project .

1.1 When to Perform an Inspection: Inspections shall be

performed before and after HVAC cleaning and restoration projects . It is also recommended that routine inspections be performed as part of a proactive energy and indoor air quality management plan .

1.2 HVAC Inspector Qualification: It is recommended that

a qualified HVAC inspector, such as an Air Systems Cleaning Specialist (ASCS), Certified Ventilation Inspector (CVI), or equivalent, be used to determine the preliminary state of HVAC system component cleanliness . At minimum, such personnel shall have a verifiable working knowledge of basic HVAC system design, fundamental HVAC engineering practices, current industry HVAC cleaning and restoration techniques, and applicable industry standards . Individuals who are inspecting for microbial contamination shall be qualified (through training and experience) and licensed (where applicable by law) to determine Conditions 1, 2 and 3 .

1.2.1 Risk Assessment: Prior to conducting an inspection

of the HVAC system components the inspector shall have a clear understanding of what impact the inspection process may have on the building environment and its occupants .

1.3 HVAC Pre-Inspection: HVAC plans, building plans, and

understanding the layout of the home or building will provide important information needed to establish the scope of work .

Both building floor plans and mechanical plans, if available, shall be used during the inspection, cleaning, and restoration work .

1.4 Appropriate Environmental Engineering Controls:

HVAC inspection activities may adversely influence a building’s indoor environment . Of primary concern is the disturbance of settled particulate and the potential for disturbed particles to be released into occupied areas . During an inspection, appropriate engineering controls shall be used to manage the general workspace environment .

1.5 Routine HVAC Inspection: It is recommended that HVAC

system component inspections be part of a building’s overall energy and indoor air quality management plan, and that the inspections be addressed in accordance with documents such as ANSI/ASHRAE/ACCA Standard 180 Standard Practice for Inspection and Maintenance of Commercial Building HVAC Systems and NFPA 90-A Standard for the Installation of Air- Conditioning and Ventilating Systems.

1.5.1 Inspection Schedule Table

HVAC system components shall be routinely inspected for cleanliness by visual means . Table 1 provides a recommended inspection schedule for major HVAC system components within different building use classifications .

The inspection intervals specified in Table 1 are minimum recommendations .

1.5.1.1 It is recommended that more frequent

cleanliness inspections be performed when geographical, human, or mechanical conditions make it necessary .

Table 1 HVAC Cleanliness Inspection Schedule

(Recommended Intervals)

Building Use Classification

Air-handling

Unit

Supply Duct

Return Duct /

Exhaust Duct

Residential 1 year 2 years 2 years

Commercial 1 year 1 year 1 year

Industrial 1 year 1 year 1 year

Healthcare 1 year 1 year 1 year

Marine 1 year 2 years 2 years

1.6 HVAC System Component Inspection – Construction, Retrofit, and Remodel: HVAC system components often collect significant amounts of debris and particulate during construction activities within a building . It is recommended that new and existing HVAC system components that are part of a construction, retrofit, or remodel project be inspected and verified as clean before the system is permitted to operate .

1.7 Performing HVAC System Component Inspections:

The cleanliness inspection shall include, at minimum, 10% of the HVAC system components being inspected . Components include, but are not limited to, supply air ducts, return air ducts, VAV boxes, fan powered terminal boxes, and mixing boxes . If the inspection is being conducted as part of a mold remediation project in accordance with ANSI/IICRC Standard S520, then all components of the HVAC system shall be inspected .

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1.7.1 Air-Handling Unit Inspections: The air-handling

unit (AHU) cleanliness inspection shall include, but is not limited to, the following components within the unit: filters and air bypass; heating and cooling coils;

condensate pans; condensate drain lines; humidification systems; acoustic insulation; fans and fan compartments;

dampers; door gaskets; and general unit integrity . This would also include components such as fan coil units, evaporative coolers, etc .

1.7.2 Supply Air Duct Inspections: The supply duct

cleanliness inspection includes, but is not limited to, the following components: air ducts; mixing boxes; VAV boxes; fan powered terminal boxes; reheat coils; and all other associated components .

1.7.3 Return Air Duct Inspections: The return air duct

cleanliness inspection includes return components including, but not limited to: return air ducts; dampers;

return plenums; and all other associated components .

1.7.4 Exhaust Air Duct Inspections: General exhaust, bathroom exhaust, and heat recovery exhaust are considered part of the ventilation system and a part of the overall inspection .

1.7.5 Damaged Components: Damaged or unsafe

components observed during the inspection shall be documented .

1.8 Exposure to Hazardous Materials: If the possibility exists that the inspector or others may be exposed to hazardous materials, consultation with a qualified indoor environmental professional (IEP) or other health and safety professional is recommended .

1.9 Inspecting for Mold Contamination: It is recommended

that the HVAC system component cleanliness inspection include a preliminary determination of the level of suspect mold contamination (Condition 1, 2, or 3) and other biological activity . In the event suspect mold growth or other biological activity is identified, it is recommended that the cause and extent be further assessed, if necessary, by an indoor environmental professional (IEP) or other appropriate professional, or as required by Authorities Having Jurisdiction .

1.9.1 If the inspection of an HVAC unit’s air-handling

components reveals suspect mold contamination, then the supply and return ducts shall be inspected during that same inspection time rather than in accordance with the intervals specified in Table 1 .

1.9.2 If water damage or suspect mold growth is

observed on building products or furnishings, this condition is not within the scope of this document .

Refer to ANSI/IICRC S520 and/or Authorities Having Jurisdiction .

1.10 System Component Assessment: Information

collected from the HVAC inspection shall be documented and evaluated to assess the condition of the HVAC system components at the time of the inspection . The assessment shall include a recommendation on the need for cleaning, a clearly defined scope of work for the cleaning and restoration project, recommended cleaning techniques, a determination of the environmental engineering controls required for the workspace, and any unique requirements .

ACR The NADCA Standard • 2021 Edition 9

Section 2 – Work Plans

2.0 Overview: Prior to the commencement of any cleaning

work, the HVAC system cleaning contractor shall provide a written work plan . A written work plan is a document that communicates responsibilities and specific tasks associated with the cleaning and restoration project . The work plan is based upon information gathered from the HVAC inspection and system assessment .

2.1 Purpose: The primary purpose for providing a written

work plan is to allow the client, the cleaning contractor, field personnel, and others involved in the project to have a clear understanding of what work tasks and procedures will be performed .

2.2 Scope of Work: A scope of work shall be included

that clearly identifies which HVAC components are to be cleaned or restored . The scope of work shall also include the environmental engineering controls required for the workspace, and any unique requirements .

2.3 Means and Methods: It is recommended that the written

work plan identify the specific means and methods of cleaning and restoration that will be used for the particular project .

2.4 Other Trades and Their Tasks: When applicable, it is

recommended that the work plan include the name of all firms, contractors, and representatives involved in the project, along with contact information . It is recommended that the tasks others will perform be clearly identified .

2.5 Project Schedule: When appropriate, it is recommended

that the work plan include the dates and times the work will take place and an overall timeframe for completion .

2.6 Work Site Communication Plan: When more than one

company is associated with the project, it is recommended that the written work plan list the name, company name and contact information of pertinent individuals, along with their responsibilities for the project .

2.7 Product Submittals: All general use and/or specific

“chemical type” products and coatings specific to the project shall be clearly listed on the work plan . Additionally, the manufacturer’s instructions for use and application shall be available at all times for workers and others .

2.7.1 Safety Data Sheets: The work plan shall include

Safety Data Sheets (SDS) for all chemical products to be used on the project . In addition, the SDS shall be maintained on-site and be available for review for the duration of the project . Documentation showing that the products have been submitted to the client for review can also be included in the work plan .

2.7.2 Controlling Vapors and Odors: Where applicable, the plan shall include a description of Engineering Controls (see Section 3) to be employed to control occupant and worker exposure to chemical vapors and odors .

2.8 Safety Plan & Safety Concerns: When life safety

detection equipment (e .g ., air duct sensors and smoke detectors) needs to be off-line or disabled, the work plan shall address life safety concerns, which will likely require the input of others . It is recommended that the written work plan define the responsibilities of each organization’s designated representative involved with executing the plan for the duration of the HVAC system cleaning and restoration project .

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ACR The NADCA Standard • 2021 Edition 11

Section 3 - Engineering Controls for HVAC Cleaning and Restoration Projects

3.0 Overview: Engineering controls shall be used to prevent

cross-contamination . Engineering controls may include but are not limited to: source control; isolation barriers; pressure differentials; dust suppression methods; HEPA vacuuming and filtration; detailed cleaning; temperature and humidity control; and a sanitary approach .

3.1 Equipment Maintenance: All contractor equipment

shall be maintained in good working order, consistent with applicable jurisdictional requirements, including but not limited to: vacuum collection equipment; power tools;

pressurized air sources; electrical power cords and plugs;

ground fault protection devices; vacuum collection hoses;

fluid and pneumatic lines; manual and mechanical rotary brush systems; robotic equipment; pneumatic cleaning systems; air duct zoning devices; ladders; staging equipment;

and hand tools .

3.1.1 Equipment Maintenance Before Project: Before

any equipment is brought onto the work site it shall be cleaned and inspected to ensure that it will not introduce contaminants into the indoor environment or HVAC system components .

3.1.2 Equipment Maintenance During a Project:

During a project, all equipment shall be serviced as needed to limit possible cross-contamination from poor hygiene, and/ or unsafe operating conditions for service personnel and building occupants .

3.1.2.1 Collector Filter Maintenance During

a Project: Any activity requiring the opening of contaminated vacuum collection equipment on-site, such as servicing, or filter maintenance shall be performed in an appropriate containment area or outside of the building .

3.1.3 Transportation and Relocation of Equipment: All

collection devices, vacuums and other tools and devices shall be cleaned or sealed before relocating to different areas of the building and before removing the equipment from the building .

3.1.4 On-Site Equipment Verification: It is recommended

that an on-site maintenance verification be performed on vacuum collection equipment prior to commencement of work .

3.2 Fuel-powered Equipment: Generators, vacuum trucks, air compressors or other fuel-powered equipment shall be positioned in a location to prevent combustion emissions and air exhaust emissions from entering an occupied space .

3.2.1 Location shall be monitored and managed during

a project to prevent the introduction of combustion emissions into the occupied space .

3.3 Vacuum Equipment Exhausting Indoors: When using

vacuum collection equipment exhausting within the building envelope, it shall utilize HEPA filtration with 99 .97% collection efficiency at 0 .3 micron particle size .

3.4 Negative Pressure Requirements: A continuous

negative pressure shall be maintained in the portion of the HVAC system components being cleaned in relation to the surrounding indoor spaces . The negative pressure shall be verified at representative locations during the cleaning process .

3.5 Handling of Contaminated Materials: To prevent cross-

contamination, all contaminated materials removed from the HVAC system components shall be properly contained prior to removal from the building .

3.5.1 Materials deemed to be hazardous by governmental

agencies shall be handled in strict accordance with any applicable local, regional or national codes .

3.6 Ambient Air Cleaning: It is recommended that ambient

air cleaning using HEPA-filtered air scrubbers be employed as a supplemental engineering control for particle reduction, during and immediately after HVAC cleaning and restoration work . It is recommended that ambient air cleaning provide a minimum of four (4) air changes per hour .

3.7 Control of Product Emissions: Any application of

cleaning agents or other chemicals shall be used in strict accordance with manufacturer’s recommended procedures and product application instructions, including exhaust ventilation as required .

3.8 Negative Pressure Failure: It is recommended that

redundant equipment be available on-site in the event of negative pressure failure .

3.9 Level 1 Containment: Level 1 is the minimum level of

containment that shall be used on all HVAC system component cleaning projects .

3.9.1 Negative Pressure: The HVAC system component, or area being cleaned/restored, shall be placed under negative pressure during all cleaning activities . Negative pressure shall be sufficient to prevent migration of any particulate material out of the HVAC system component .

3.9.2 Protective Coverings: Clean, protective coverings

shall be used within the work area . Protective coverings shall extend beyond the work area to provide protection of flooring, equipment, and furniture whenever necessary .

3.9.3 Cleaning Equipment and Tools: All tools

and equipment shall be maintained as described in Section 3 .1 .

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3.9.4 Cross-Contamination Control: Engineering

controls shall be in place to control contaminant discharge from the HVAC system components and/or cross-contamination into occupied space during the cleaning process .

3.10 Level 2 Containment (Temporary Barriers):

3.10.1 Include Level 1 requirements: All Level 1

containment requirements apply to Level 2 containments .

3.10.2 Temporary Containment Barriers:

Temporary barriers shall be constructed to isolate the work area .

3.10.2.1 It is recommended that containment barriers

be erected from floor to ceiling when applicable .

3.10.2.2 It is recommended that above-ceiling work

areas are isolated from occupied spaces and/or non-work areas when applicable .

3.10.2.3 It is recommended that containment barriers

are built utilizing 6-mil fire retardant polyethylene sheeting or equivalent .

3.10.2.4 These barriers are recommended to be

sealed airtight where they meet the ceiling, floor, and walls or other areas .

3.10.3 Containment Area Floor: The containment

shall have a two-layer floor utilizing 6-mil fire retardant polyethylene or equivalent . The floor material shall extend at least 6 inches (15 .2 centimeters) up the containment side walls . The floor material shall be sealed to side walls in a manner that will remain secure and airtight during the depressurization .

3.10.4 Containment Area Access: A zipper-type access, with a single flap covering the zipper is the most common work practice .

3.10.4.1 In the event a zipper is not available or

practical, then a vertical cut in the containment side wall can provide access into the containment area .

The vertical cut shall be entirely covered by two flaps, one on each side of the polyethylene .

3.10.5 Negative Pressure: The containment area shall

be kept under negative pressure at all times . The negative pressure shall be sufficient to prevent airborne migration of particulate material out of the containment area .

3.10.6 Validate Negative Pressurization: A manometer

or airflow measuring/monitoring device shall be used to validate negative pressurization .

3.10.7 Ambient Air Cleaning Ambient air cleaning with

HEPA-filtered air scrubbers shall be performed . Ambient air cleaning shall maintain, at minimum, four (4) air changes per hour .

3.10.8 Dismantling: Interior surfaces of the containment

enclosure shall be wet-wiped and/or HEPA vacuumed before moving or dismantling the containment enclosure . In the healthcare environment, an appropriate post- remediation verification shall be performed prior to dismantling the containment .

3.11 Level 3 Containment: Level 3 is a containment with a

single chamber decontamination unit .

3.11.1 Include Level 1 and Level 2 Requirements: All

of the Level 1 and 2 containment requirements apply to Level 3 containments . In addition, the following protective actions shall be used under Level 3 Containment strategies .

3.11.2 Decontamination Facility: A single chamber

decontamination facility shall be utilized in conjunction with the containment area . The decontamination chamber shall be attached and sealed directly to the containment area . The decontamination chamber shall be separated from the containment area by a zipper access with single flap or the use of two flaps as described in Level 2 Containment .

3.11.3 Monitoring Requirements: Level 3 containment

areas shall be monitored for negative pressure on a continuous basis by using an instrument sensitive enough to detect a loss of negative pressure . Background monitoring for total particulate shall be performed prior to set-up of containment to establish baseline airborne total particulate concentrations . It is recommended that monitoring also be conducted during set-up of containment . Real time monitoring for total particulate shall be conducted on a regular basis during the work to ensure that particulate is not escaping the containment .

If airborne particulate levels exceed background levels, work shall cease until airborne particulate levels are reduced to background levels and the cause of the problem is found and corrected .

3.12 Level 4 Containment: A Level 4 containment is a

containment with a two chamber decontamination unit .

3.12.1 Include Level 1, Level 2 and Level 3

Requirements: All of the Level 1, Level 2, and Level 3 containment requirements apply to Level 4 containment areas . In addition, the following protective actions shall be used under Level 4 containment strategies .

3.12.2 Decontamination Facility: A decontamination

facility as described for a Level 3 containment area shall be utilized, except that the decontamination facility shall consist of two chambers . Each chamber shall be constructed according to the requirements described for a Level 3 containment area .

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3.12.3 Monitoring Requirements: Monitoring

requirements described for a Level 3 containment area apply . In addition, the containment shall have a constant recording pressurization monitor with an appropriate alarm .

3.13 Summary of Engineering Controls: Appropriate

engineering controls are mandatory on every HVAC cleaning and restoration project . Protecting workers and building occupants and preventing cross-contamination shall be considered a priority on every project . It is recommended that the above listed engineering controls are considered minimum requirements . When a contractor has any questions about project-specific engineering controls, it is recommended that an Indoor Environmental Professional (IEP) be consulted .

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Section 4 - Cleaning and Restoration Procedures

4.0 Overview: All cleaning and restoration procedures shall

achieve the minimum level of visibly clean or the specified level of cleanliness verification as defined in the contractual documents for components within the project scope of work .

4.1 Negative Duct Pressurization: Prior to and throughout

the duration of the cleaning process, the HVAC system components and associated air ducts shall be kept at an appropriate negative pressure differential relative to the indoor non-work area . This negative pressure differential shall be maintained between the portion of the HVAC duct system components being cleaned and surrounding indoor occupant spaces .

4.1.1 Verifying Negative Pressure Differential:

Under all circumstances, you shall verify pressurization differential during the project .

4.1.2 Equipment Exhausting Indoors: Vacuum

collection equipment exhausting indoors shall be HEPA-filtered and be capable of retaining dislodged debris .

4.1.3 Equipment Exhausting Outdoors: All equipment

used to create negative duct pressurization that does not have HEPA filtration shall be exhausted outdoors .

4.2 Service Openings: Service openings may be needed

to perform assessment, cleaning and restoration (ACR) procedures . Below are the minimum requirements for service openings .

4.2.1 Service openings installed into the system shall

not degrade the structural, thermal, or functional integrity of the system components .

4.2.2 Service openings shall be created in a manner

that allows for proper closure .

4.2.3 Service openings shall not hinder, restrict, or alter

the airflow within the air duct .

4.2.4 Service openings shall be in compliance with

industry standards and local codes, using materials acceptable under those standards and codes .

4.2.5 Service Panels

4.2.5.1 Service panels used for closing service

openings in the HVAC system components shall be of an equivalent gauge or heavier so as to not compromise the structural integrity of the duct .

4.2.5.2 Service panels used for closing service

openings shall be mechanically fastened (screwed or riveted) at minimum every 4” on center . The panel shall overlap the ductwork surfaces by a minimum of 1” on all sides .

4.2.5.3 It is recommended that service panels used

for closing service openings be sealed with gaskets, duct sealants, mastic or tape .

4.2.5.4 All tapes and mastics used in the closure of

service openings shall meet the requirements of UL 181A/B.

4.2.6 Prefabricated Duct Access Doors: The gauge of

the duct access door shall be based on the pressure class of the duct system and shall be installed according to manufacturers’ specifications .

4.2.7 Flammability and Smoke Spread Rating:

Materials used in the fabrication of duct access doors and service panels shall be those classified for flammability and smoke spread if the material is exposed to the ducted airside surface . These materials are classified as having a flame-spread rating of not over 25 without evidence of continued progressive combustion and a smoke-developed rating of not over 50, as determined by UL 723 .

These materials shall comply with SMACNA and other applicable standards .

4.2.8 Fibrous Glass System Service Openings

4.2.8.1 Access and closure of service openings

installed in fibrous glass shall be created and closed in such a manner that there are no exposed fibrous glass edges within the system common to the airstream .

4.2.8.2 Any fibrous glass removed during the

installation of a service opening shall be repaired or replaced with like material of the same thickness so that there are no breaks or openings that would degrade the R value, service rating or vapor/air barrier characteristics .

4.2.9 Flexible Duct Systems: Service openings shall

not be made in flexible ductwork .

4.2.10 All service openings shall comply with applicable

UL, SMACNA and NFPA standards, as well as local, regional, and state codes .

4.3 Cleaning and Restoration of HVAC Systems: HVAC

systems shall be cleaned by using a suitable agitation device to dislodge non-adhered substances from the HVAC component airside surface and then capturing the dislodged debris with a vacuum collection device .

4.4 Wet Cleaning, Power Washing, and Steam Cleaning:

Wet cleaning, power washing, steam cleaning and any other form of wet process cleaning of HVAC system components shall not damage or result in subsequent damage to the components . Cleaning agents or water shall never be applied to electrical, fibrous glass or other porous HVAC system components .

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4.5 Vacuum Collection Equipment: Vacuum collection

equipment shall be operated continuously during cleaning .

The collection equipment shall be used in conjunction with agitation tools and other equipment to convey and collect debris and prevent cross-contamination of dislodged particulate during the mechanical cleaning process .

4.5.1 Capture Velocity: When the vacuum collection

device is used to convey air with debris, it shall maintain a sufficient velocity and negative pressure differential in the portion of the HVAC system component being cleaned .

Table 2 defines recommended velocities for various types of contaminants .

4.6 Air-Handling Unit (AHU) Cleaning: It is recommended

that air-handling coils, fans, condensate pans, drains and similar non-porous surfaces be wet cleaned in conjunction with mechanical methods .

4.6.1 Efforts to control water extraction shall be

sufficient to collect debris and prevent water damage to the HVAC components and surrounding equipment and structure .

4.6.2 The capture, containment, testing and disposal

of waste water generated while performing wet cleaning shall be in accordance with applicable local, regional, state and federal regulations .

4.7 Air Duct Cleaning: Air ducts shall be cleaned to remove

all non-adhered substances and shall be capable of passing NADCA cleanliness verification tests .

4.7.1 Air ducts shall be accessed through service

openings in the system that are large enough to accommodate mechanical cleaning procedures and allow for cleanliness verification .

4.7.2 Air ducts shall be cleaned using mechanical

agitation methods to remove particulate, debris, and surface contamination .

4.7.3 Dislodged substances shall be captured with a

vacuum collection device .

4.7.4 Cleaning activities shall not damage any HVAC

components .

4.8 Dampers: Dampers and any air-directional mechanical

devices shall have their position marked prior to cleaning and shall be restored to their marked position after cleaning .

4.9 Registers, Grilles, Diffusers: It is recommended that all registers, grilles, diffusers, and other air distribution devices be removed if possible, properly cleaned, and shall be restored to their previous position .

4.10 Smoke and/or Fire Detection Equipment: Cleaning

activities shall not impair, alter or damage any smoke and fire detection equipment located within the facility, or attached to and serving the HVAC system components .

Table 2 Range of Minimum Duct Design Velocities

Nature of Contaminant

Examples Design Velocity

Vapors, gases, smoke Any desired velocity (economic optimum velocity usually 1,000-2,000 fpm) [5.08-10.16 m/s]

Fumes, metal smokes Welding 2,000-2,500 fpm [10.16-12.70 m/s]

Fine light dust Cotton lint, wood flour, litho powder 2,500-3,000 fpm [12.7-15.24 m/s]

Dry dusts and powders Fine rubber dust, Bakelite molding powder dust, jute lint, cotton dust, shavings (light), soap dust, leather shavings

3,000-3,500 fpm [15.24-17.78 m/s]

Average industrial dust Grinding dust, buffing lint (dry), wool jute dust (shaker waste), coffee beans, shoe dust, granite dust, silica flour, general material handling, brick cutting, clay dust, foundry (general), limestone dust, packaging and weighing asbestos dust in textile industries

3,500-4,000 fpm [17.78-20.32 m/s]

Heavy dusts Sawdust (heavy and wet), metal turnings, foundry tumbling barrels and shake-out, sand blast dust, wood blocks, hog waste, brass turnings, cast iron boring dust, lead dust

4,000-4,500 fpm [20.32-22.86 m/s]

Heavy or moist dusts Lead dusts with small chips, moist cement dust, buffing lint (sticky), quick-lime dust

4,500 fpm [22.86 m/s] and up

Reprinted from ACGIH Industrial Ventilation: A Manual of Recommended Practice

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4.11 Coil Surface Cleaning: When coil cleaning is performed, both upstream and downstream sides of each coil section shall be accessed for cleaning . When both sides of a coil are not accessible for cleaning then removal and/or replacement may be required .

4.11.1 Preliminary Coil Inspection: A visual inspection

of the coil and drain pan shall be conducted prior to cleaning a coil to determine whether Type 1 (Dry Cleaning) or Type 2 (Wet Cleaning) is required .

4.11.1.1 If it is determined the coil cannot be properly

cleaned through Type 1 (Dry Cleaning), Type 2 (Wet Cleaning) shall be performed .

4.11.1.2 If the preliminary visual inspection reveals

suspect microbial contamination on any portion of the coil or drain pan, Type 2 (Wet Cleaning) shall be performed .

4.11.1.3 When the metal fins of the coil are

damaged, deteriorating, or showing signs of corrosion, replacement may be necessary . If cleaning will result in further damage to the coil, replacement is recommended .

4.11.2 Type 1 Coil Cleaning (Dry Cleaning): Type

1 (Dry Cleaning) methods of coil cleaning shall be used for removing loose dust, dirt or debris collected upon coil surfaces . Negative air machines shall be operated continuously during Type 1 (Dry Cleaning) coil cleaning process . The coil shall be isolated from the duct system during the cleaning process to ensure disrupted particulate does not migrate to, or redeposit on, unintended areas . Physical removal of debris may be accomplished through a variety of methods which may include:

• HEPA-filtered contact vacuuming

• Brushes for penetrating between coil fins

• Compressed air

• Fin straightening tools

4.11.3 Type 1 (Dry Cleaning) Post-Cleaning

Inspection: This inspection shall be performed after Type 1 (Dry Cleaning) coil cleaning has been completed .

If debris still remains on the coil or the coil is impacted, Type 2 (Wet Cleaning) shall be performed .

4.11.4 Type 2 Coil Cleaning (Wet Cleaning): Type 2

(Wet Cleaning) methods are appropriate for removing adhered debris on all coil, drain pan, and drain line surfaces .