NADCA GENERAL SPECIFICATIONS FOR THE CLEANING OF C

National Air Duct Cleaners Association

1518 K Street, N.W., Suite 503

Washington, DC 20005

(202) 737-2926 · Fax (202) 347-8847

E-mail nadca@aol.com · Web Site http://www.nadca.comINTRODUCTION

This recommended General Specification was prepared by the National Air Duct Cleaners Association (NADCA). It describes the minimum requirements necessary to coordinate a successful commercial HVAC system cleaning project.

This document was created for use by building owners, managers and engineers in the development of cleaning specifications applicable to a certain building or group of buildings. Therefore, this document must be modified to accurately account for the unique system variations within an individual building.

This specification is written as an owner’s specification, however, substitutions may be made by inserting “mechanical contractor,” “general contractor,” or “architect,” where designated in boldface type.

The use of this specification in and of itself is no guarantee of a successful project. Sufficient coordination by the owner, including the selection of a qualified contractor, is equally important as a good specification.

This document was created for projects performed in the United States of America. For projects outside of the U.S.A., users of this specification are advised to consult applicable laws, standards and regulations of their country to ensure that the contents of this specification do not conflict with such statutes.

For more information about HVAC system cleaning, please contact:

National Air Duct Cleaners Association

1518 K Street, N.W., Suite 503

Washington, DC 20005

(202) 737-2926

Fax (202) 347-8847

E-mail: nadca@aol.com

Web Site: www.nadca.comDISCLAIMER

This sample specification was developed by the National Air Duct Cleaners Association (NADCA) and is intended to provide information on general guidance on standard provisions describing the minimally acceptable criteria for performing commercial HVAC system cleaning. The guidelines provided are based on the collective experience of members of the industry, but are not intended to be either exhaustive or inclusive of all pertinent requirements. The information provided in this specification is offered in good faith and believed to be reliable, but is made WITHOUT WARRANTY, EXPRESSED OR IMPLIED, AS TO THE MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR ANY OTHER MATTER. The provisions included are not intended to be directed to any particular product, method or contractor, nor are they claimed to satisfy all current legal requirements related to contractual relationships for commercial duct cleaning projects. Following the specification does not guarantee compliance with any regulation, nor safe, satisfactory, or complete performance of HVAC system cleaning. Users are cautioned that the information upon which this specification is based is subject to change, which may invalidate any or all of the comments contained herein. The specification is not intended to provide specific advice, legal or otherwise, on particular methods or agreements between contractors and owners of buildings. In preparing project specifications, users of this specification should consult with their own legal and technical advisors, their suppliers, and other appropriate sources (including but not limited to technical standards on duct cleaning and related activities, product technical bulletins or sales literature, and government building codes and standards) which contain information about minimum performance criteria for duct work and associated building systems. NADCA, its members, and contributors do not assume any responsibility for the user's compliance with any applicable laws and regulations, nor for any persons relying on the information contained in this specification. NADCA does not endorse the proprietary products, methods, or individual HVAC system cleaning companies.

Copyright by NADCA ©1997, Washington, D.C. No part of this document may be reproduced, electronically or in paper copy, for commercial sale. Users are welcome to reproduce and/or modify this document to suit their own purposes for use on specific projects. All other rights reserved.NADCA General Specifications

Contents

Part 1 -- Special Provisions

1.01 Qualification of the HVAC System Cleaning Contractor

(A) Membership

(B) Certification

(C) Supervisor Qualifications

(D) Experience

(E) Equipment, Materials and Labor

(F) Licensing

1.02 Standards

(A) NADCA Standards

1.03 Documents

(A) Mechanical Drawings

Part 2 -- HVAC System Cleaning Specifications and Requirements

2.01 Scope of Work

(A) Scope

2.02 HVAC System Inspections and Site Preparations

(A) HVAC System Evaluation

(B) Site Evaluation and Preparations

2.03 General HVAC System Cleaning Requirements

(A) Containment

(B) Particulate Collection

(C) Controlling Odors

(D) Component Cleaning

(E) Air-Volume Control Devices

(F) Service Openings

(G) Ceiling sections (tile)

(H) Air distribution devices (registers, grilles & diffusers)

(I) Air handling units, terminal units, blowers and exhaust fans

(J) Duct Systems

2.04 Health and Safety

(A) Safety Standards

(B) Occupant Safety

(C) Disposal of Debris

2.05 Mechanical Cleaning Methodology

(A) Source Removal Cleaning Methods

(B) Methods of Cleaning Fibrous Glass Insulated Components

(C) Damaged Fibrous Glass Material

(D) Cleaning of coils

(E) Biocidal Agents and Coatings

2.06 Cleanliness Verification

(A) General

(B) Visual Inspection

(C) Gravimetric Analysis

(D) Verification of Coil Cleaning

2.07 Pre-Existing System Damage

2.08 Post-Project Report

2.09 Applicable Standards and Publications

NADCA General SpecificationsPart 1 -- Special Provisions

1.01 Qualification of the HVAC System Cleaning Contractor:

(A) Membership: The HVAC system cleaning contractor shall be a certified member

of the National Air Duct Cleaners Association (NADCA), or shall maintain

membership in a nationally recognized non-profit industry organization dedicated to

the cleaning of HVAC systems.

(B) Certification: The HVAC system cleaning contractor shall have a minimum of

one (1) Air System Cleaning Specialist (ASCS) certified by NADCA on a full time

basis, or shall have staff certified by a nationally recognized certification program

and organization dedicated to the cleaning of HVAC systems.

(C) Supervisor Qualifications: A person certified as an ASCS by NADCA, or

maintaining an equivalent certification by a nationally recognized program and

organization, shall be responsible for the total work herein specified.

(D) Experience: The HVAC system cleaning contractor shall submit records of

experience in the field of HVAC system cleaning as requested by the owner. Bids

shall only be considered from firms which are regularly engaged in HVAC system

maintenance with an emphasis on HVAC system cleaning and decontamination.

(E) Equipment, Materials and Labor: The HVAC system cleaning contractor shall

possess and furnish all necessary equipment, materials and labor to adequately

perform the specified services.

1. The contractor shall assure that its employees have received safety

equipment training, medical surveillance programs, individual health

protection measures, and manufacturer’s product and material safety data

sheets (MSDS) as required for the work by the U.S. Occupational Safety and

Health Administration, and as described by this specification. For work

performed in countries outside of the U.S.A., contractors should comply with

applicable national safety codes and standards.

2. The contractor shall maintain a copy of all current MSDS documentation

and safety certifications at the site at all times, as well as comply with all

other site documentation requirements of applicable OSHA programs and this

specification

3. Contractor shall submit to the owner all Material Safety Data Sheets

(MSDS) for all chemical products proposed to be used in the cleaning

process.

(F) Licensing: The HVAC system cleaning contractor shall provide proof of

maintaining the proper license(s), if any, as required to do work in this state.

Contractor shall comply with all Federal, state and local rules, regulations, and

licensing requirements.

Standards.

1.02(A) NADCA Standards: The HVAC system cleaning contractor shall perform the

services specified here in accordance with the current published standards of the

National Air Duct Cleaners Association (NADCA).

1. All terms in this specification shall have their meaning defined as stated in

the NADCA Standards.

2. NADCA Standards must be followed with no modifications or deviations

being allowed.

1.03 Documents

(A) Mechanical Drawings: The owner shall provide the HVAC system cleaning

contractor with one copy of the following documents:

1. Project drawings and specifications

2. Approved construction revisions pertaining to the HVAC system

3. Any existing indoor air quality (IAQ) assessments or environmental reports

prepared for the facility.

Part 2 -- HVAC System Cleaning Specifications and Requirements

2.01 Scope of Work

(A) Scope: This section defines the minimum requirements necessary to render

HVAC components clean, and to verify the cleanliness through inspection and/or

testing in accordance with items specified herein and applicable NADCA Standards.

The Contractor shall be responsible for the removal of visible surface contaminants

and deposits from within the HVAC system in strict accordance with these

specifications.

The HVAC system includes any interior surface of the facility’s air distribution system

for conditioned spaces and/or occupied zones. This includes the entire heating, air-

conditioning and ventilation system from the points where the air enters the system

to the points where the air is discharged from the system. The return air grilles,

return air ducts (except ceiling plenums and mechanical room) to the air handling

unit (AHU), the interior surfaces of the AHU, mixing box, coil compartment,

condensate drain pans, humidifiers and dehumidifiers, supply air ducts, fans, fan

housing, fan blades, air wash systems, spray eliminators, turning vanes, filters, filter

housings, reheat coils, and supply diffusers are all considered part of the HVAC

system. The HVAC system may also include other components such as dedicated

exhaust and ventilation components and make-up air systems.

Note: Users of this specification must modify the above paragraph to succinctly and

specifically define those systems and components requiring cleaning.

2.02 HVAC System Inspections and Site Preparations

(A) HVAC System Evaluation: Prior to the commencement of any cleaning work, the

HVAC system cleaning contractor shall perform a visual inspection of the HVAC

system to determine appropriate methods, tools, and equipment required to

satisfactorily complete this project.

1. Damaged system components found during the inspection shall be

documented and brought to the attention of the owner.

(B) Site Evaluation and Preparations: Contractor shall conduct a site evaluation, and

establish a specific, coordinated plan which details how each area of the building will be protected during the various phases of the project.

2.03 General HVAC System Cleaning Requirements

(A) Containment: Debris removed during cleaning shall be collected and precautions

must be taken to ensure that Debris is not otherwise dispersed outside the HVAC

system during the cleaning process.

(B) Particulate Collection: Where the Particulate Collection Equipment is exhausting

inside the building, HEPA filtration with 99.97% collection efficiency for 0.3-micron

size (or greater) particles shall be used. When the Particulate Collection Equipment is exhausting outside the building, Mechanical Cleaning operations shall be

undertaken only with Particulate Collection Equipment in place, including adequate

filtration to contain Debris removed from the HVAC system. When the Particulate

Collection Equipment is exhausting outside the building, precautions shall be taken

to locate the equipment down wind and away from all air intakes and other points of entry into the building.

(C) Controlling Odors: All reasonable measures shall be taken to control offensive

odors and/or mist vapors during the cleaning process.

(D) Component Cleaning: Cleaning methods shall be employed such that all HVAC

system components must be Visibly Clean as defined in applicable standards (see

NADCA Standards). Upon completion, all components must be returned to those

settings recorded just prior to cleaning operations.

(E) Air-Volume Control Devices: Dampers and any air-directional mechanical

devices inside the HVAC system must have their position marked prior to cleaning

and, upon completion, must be restored to their marked position.

(F) Service Openings: The contractor shall utilize service openings, as required for

proper cleaning, at various points of the HVAC system for physical and mechanical

entry, and inspection.

1. Contractor shall utilize the existing service openings already installed in the

HVAC system where possible.

2. Other openings shall be created where needed and they must be createdso they can be sealed in accordance with industry codes and standards.

3. Closures must not significantly hinder, restrict, or alter the air-flow within

the system.

4. Closures must be properly insulated to prevent heat loss/gain or

condensation on surfaces within the system.

5. Openings must not compromise the structural integrity of the system.

6. Construction techniques used in the creation of openings should conform

to requirements of applicable building and fire codes, and applicable NFPA,

SMACNA and NADCA Standards.

7. Cutting service openings into flexible duct is not permitted. Flexible duct

shall be disconnected at the ends as needed for proper cleaning and

inspection.

8. Rigid fiber glass ductboard duct systems shall be resealed in accordance

with NAIMA recommended practices. Only closure techniques which comply with UL Standard 181 or UL Standard 181a are suitable for fiber glass duct

system closures.

9. All service openings capable of being re-opened for future inspection or

remediation shall be clearly marked and shall have their location reported to

the owner in project report documents.

(G) Ceiling sections (tile): The contractor may remove and reinstall ceiling sections to gain access to HVAC systems during the cleaning process.

(H) Air distribution devices (registers, grilles & diffusers): The contractor shall clean all air distribution devices.

(I) Air handling units, terminal units (VAV, Dual duct boxes, etc.), blowers and exhaust fans: The contractor shall insure that supply, return, and exhaust fans and blowers are thoroughly cleaned. Areas to be cleaned include blowers, fan housings, plenums (except ceiling supply and return plenums), scrolls, blades, or vanes, shafts, baffles, dampers and drive assemblies. All visible surface contamination deposits shall be removed in accordance with NADCA Standards. Contractor shall:

1. Clean all air hadling unit (AHU) internal surfaces, components and

condensate collectors and drains.

2. Assure that a suitable operative drainage system is in place prior to

beginning wash down procedures.

3. Clean all coils and related components, including evaporator fins.

(J) Duct Systems: Contractor shall:1. Create service openings in the system as necessary in order to

accommodate cleaning of otherwise inaccessible areas.

2. Mechanically clean all duct systems to remove all visible contaminants,

such that the systems are capable of passing Cleaning Verification Testings

(see NADCA Standards).

2.04 Health and Safety

(A) Safety Standards: Cleaning contractors shall comply with all applicable federal,

state, and local requirements for protecting the safety of the contractors' employees, building occupants, and the environment. In particular, all applicable standards of

the Occupational Safety and Health Administration (OSHA) shall be followed when working in accordance with this specification.

(B) Occupant Safety: No processes or materials shall be employed in such a

manner that they will introduce additional hazards into occupied spaces.

(C) Disposal of Debris. All Debris removed from the HVAC System shall be

disposed of in accordance with applicable federal, state and local requirements.

2.05 Mechanical Cleaning Methodology

(A) Source Removal Cleaning Methods: the HVAC system shall be cleaned using

Source Removal mechanical cleaning methods designed to extract contaminants

from within the HVAC system and safely remove contaminants from the facility. It is the contractor’s responsibility to select Source Removal methods which will render

the HVAC system Visibly Clean and capable of passing cleaning verification

methods (See applicable NADCA Standards) and other specified tests, in

accordance with all general requirements. No cleaning method, or combination of

methods, shall be used which could potentially damage components of the HVAC

system or negatively alter the integrity of the system.

1. All methods used shall incorporate the use of vacuum collection devices

that are operated continuously during cleaning. A vacuum device shall be

connected to the downstream end of the section being cleaned through a

predetermined opening. The vacuum collection device must be of sufficient

power to render all areas being cleaned under negative pressure, such that

containment of debris and the protection of the indoor environment is

assured.

2. All vacuum devices exhausting air inside the building shall be equipped

with HEPA filters (minimum efficiency), including hand-held vacuums and

wet-vacuums.

3. All vacuum devices exhausting air outside the facility shall be equipped

with Particulate Collection including adequate filtration to contain Debris

removed from the HVAC system. Such devices shall exhaust in a manner

that will not allow contaminants to re-enter the facility. Release of debrisoutdoors must not violate any outdoor environmental standards, codes or

regulations.

4. All methods require mechanical agitation devices to dislodge debris

adhered to interior HVAC system surfaces, such that debris may be safely

conveyed to vacuum collection devices. Acceptable methods will include

those which will not potentially damage the integrity of the ductwork, nor

damage porous surface materials such as liners inside the ductwork or

system components.

(B) Methods of Cleaning Fibrous Glass Insulated Components:

1. Fibrous glass thermal or acoustical insulation elements present in any

equipment or ductwork shall be thoroughly cleaned with HEPA vacuuming

equipment, while the HVAC system is under constant negative pressure, and not permitted to get wet in accordance with applicable NADCA and NAIMA

standards and recommendations.

2. Cleaning methods used shall not cause damage to fibrous glass

components and will render the system capable of passing Cleaning

Verification Tests (see NADCA Standards).

(C) Damaged Fibrous Glass Material

1. If there is any evidence of damage, deterioration, delamination, friable

material, mold or fungus growth, or moisture such that fibrous glass materials cannot be restored by cleaning or resurfacing with an acceptable insulation

repair coating, they shall be identified for replacement.

2. When requested or specified, Contractor must be capable of remediating

exposed damaged insulation in air handlers and/or ductwork requiring

replacement.

3. Replacement material: In the event fiber glass materials must be replaced,

all materials shall conform to applicable industry codes and standards,

including those of UL and SMACNA.

Replacement of damaged insulation is not covered by this specification.

(D) Cleaning of coils

1. Any cleaning method may be used which will render the Coil Visibly Clean

and capable of passing Coil Cleaning Verification (see applicable NADCA

Standards). Coil drain pans shall be subject to Non-Porous Surfaces

Cleaning Verification. The drain for the condensate drain pan shall be

operational. Cleaning methods shall not cause any appreciable damage to,

displacement of, inhibit heat transfer, or erosion of the coil surface or fins,

and shall conform to coil manufacturer recommendations when available.Coils shall be thoroughly rinsed with clean water to remove any latent

residues.

(E) Biocidal Agents and Coatings

1. Biocidal agents shall only be applied if active fungal growth is reasonably

suspected, or where unacceptable levels of fungal contamination have been

verified through testing.

2. Application of any biocidal agents used to control the growth of fungal or

bacteriological contaminants shall be performed after the removal of surface

deposits and debris.

3. Only biocidal agents registered by the U.S. Environmental Protection

Agency (EPA) specifically for use within HVAC system shall be used.

4. Biocidal agents shall be applied in strict accordance with manufacturer’s

instructions.

5. Biocidal coating products for both porous and non-porous surfaces shall be

EPA registered, water soluble solutions with supporting efficacy data and

MSDS records.

6. Biocidal coatings shall be applied according to manufacturer’s instructions.

Coatings shall be sprayed directly onto interior ductwork surfaces, rather than

“fogged” downstream onto surfaces. A continuous film must be achieved on

the surface to be treated by the coating application. Application of any

biocidal coatings shall be in strict accordance with manufacturer’s minimum

millage surface application rate standards for effectiveness.

2.06 Cleanliness Verification

(A) General: Verification of HVAC System cleanliness will be determined after

mechanical cleaning and before the application of any treatment or introduction of

any treatment-related substance to the HVAC system, including biocidal agents and coatings.

(B) Visual Inspection: the HVAC system shall be inspected visually to ensure that no

visible contaminants are present.

1. If no contaminants are evident through visual inspection, the HVAC system

shall be considered clean; however, the owner reserves the right to further

verify system cleanliness through gravimetric or wipe testing analysis testing

as specified herein.

2. If visible contaminants are evident through visual inspection, those portions

of the system where contaminants are visible shall be re-cleaned and

subjected to re-inspection for cleanliness.

(C) Gravimetric Analysis: At the discretion and expense of the owner, sections ofthe HVAC system may be tested for cleanliness using the NADCA Vacuum Test

(gravimetric analysis) as specified in applicable NADCA Standards. Levels of debris collected shall be equal to or less than acceptable levels defined in applicable

NADCA Standards.

1. If gravimetric analysis determines that levels of debris are equal to or lower

than those levels specified in applicable NADCA standards, the system shall

be considered clean and shall have passed cleanliness verification.

2. If gravimetric analysis determines that levels of debris exceed those

specified in applicable NADCA standards, the system shall not be considered

clean and those sections of the system which failed cleanliness verification

shall be re-cleaned at the expense of the HVAC system cleaning contractor.

3. Gravimetric analysis shall be performed by a qualified third party

experienced in testing of this nature.

4. Cleanliness verification shall be performed immediately after mechanical

cleaning and before the HVAC system is restored to normal operation.

(D) Verification of Coil Cleaning

1. Cleaning must restore the coil pressure drop to within 10 percent of the

pressure drop measured when the coil was first installed. If the original

pressure drop is not known, the coil will be considered clean only if the coil is

free of foreign matter and chemical residue, based on a thorough visual

inspection (see NADCA Standards).

2.07 Pre-Existing System Damage

(A) Contractor is not responsible for problems resulting from prior inappropriate or

careless cleaning techniques of others.

2.08 Post-Project Report

(A) At the conclusion of the project, the Contractor shall provide a report to the

owner indicating the following:

1. Success of the cleaning project, as verified through visual inspection

and/or gravimetric analysis.

2. Areas of the system found to be damaged and/or in need of repair.

2.09 Applicable Standards and Publications -- The following current standards and publications of the issues currently in effect form a part of this specification to the extent indicated by any reference thereto:

(A) National Air Duct Cleaners Association (NADCA): NADCA 1992-01, “Mechanical

Cleaning of Non-Porous Air Conveyance System Components,” 1992

This General Specification describes the minimum requirements necessary for commercial HVAC system cleaning. This document must be modified to accurately account for the unique system variations within an individual building.

(B) National Air Duct Cleaners Association (NADCA): “Understanding Microbial

Contamination in HVAC Systems,” 1996.

(C) National Air Duct Cleaners Association (NADCA): “Introduction to HVAC System

Cleaning Services,” 1995.

(D) National Air Duct Cleaners Association (NADCA) NADCA Standard 05

“Requirements for the Installation of Service Openings in HVAC Systems,” 1997.

(E) Underwriters’ Laboratories (UL): UL Standard 181

(F) American Society of Heating, Refrigerating and Air Conditioning Engineers

(ASHRAE): Standard 62-, "Ventilation for Acceptable Indoor Air Quality"

(G) Environmental Protection Agency (EPA): "Building Air Quality" December, 1991

(H) Sheet Metal and Air Conditioning Contractors' National Association (SMACNA):

“HVAC Duct Construction Standards - Metal and Flexible,” 1985

(I) North American Insulation Manufacturers Association (NAIMA): "Cleaning Fibrous

Glass Insulated Air Duct Systems." 1993

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