air systems cleaning specialist (ascs) to acr, … · air systems cleaning specialist (ascs) to the...

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Copyright © 2016 NADCA, All Rights Reserved

No part of this publication may be reproduced or distributed by any means, electronic or mechanical, including photocopy, recording, or any other information storage and retrieval system, without prior written consent from the publisher.

AIR SYSTEMS CLEANING SPECIALIST (ASCS) TO ACR, THE NADCA STANDARD

A NADCA APPROVED COURSE

Module 1 – History of Heating, Ventilation and Air-Conditioning (HVAC) Systems Cleaning


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WHAT WE’LL LEARN:

History of Heating Ventilation and Air‐Conditioning (HVAC) Systems Cleaning

Composition of HVAC Contamination

National Air Duct Cleaning Association (NADCA)

History of HVAC Systems Cleaning3

Heating, Ventilation and Air‐Conditioning (HVAC) Systems Cleaning, commonly referred to as “duct cleaning” traces it’s roots back to the mid‐1900’s.

History of HVAC Systems Cleaning 4

Source: Watkins Household Hints, 1941

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Over the past 30 years duct cleaning techniques have evolved.


The commonly accepted terminology has become HVAC cleaning and restoration or HVAC remediation.

Duct Cleaning ‐ The Misnomer

“If you decide to have your heating and cooling system cleaned, it’s important to make sure the service provider agrees to clean all components of the system and is qualified to do so.” – US EPA


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EPA Document ‐ Should You Have the Air Ducts in Your Home Cleaned?

It is important to review, evaluate and understand all federal reference materials…. When assessing duct systems, the EPA may be a higher authority on the subject. (Reference EPA‐402‐K‐97‐002)


Any substance not originally intended to be present in the air duct system is suspect for being a contaminant.

Mold Contaminated Fiber Glass Ductboard

Composition of HVAC Contamination8

Contaminated Metal Turning Vanes

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What is the definition of a Micron?


A Micron is a unit of measurement for particle size. There are over 25,000 microns in one lineal inch.



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This dimension represents the diameter of a human hair, 100 microns

The National Air Duct Cleaners Association (NADCA)

The growing HVAC remediation industry made a significant step forward in 1989 by forming a non‐profit organization dedicated to increasing professionalism in the HVAC remediation industry.

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First to develop an International Standard for HVAC remediation

Provides certification and training to promote industry standards

Instrumental in creation of the consumer guide for residential and commercial system cleaning

Partnered with EPA to research effectiveness of duct cleaning on HVAC Systems

The National Air Duct Cleaners Association (NADCA)13

ACR, The NADCA StandardAssessment, Cleaning

and Restoration of HVAC Systems

The National Air Duct Cleaners Association (NADCA)14

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The National Air Duct Cleaners Association (NADCA)

Provides a variety of resources and reference materials for HVAC remediation industry professionals:

ACR, The NADCA Standard

NADCA Safety Manual

General Specifications for the Cleaning of Commercial HVAC Systems

Introduction to HVAC Cleaning Systems

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Which of the following is the current version of ACR, The NADCA Standard? ____________

(A) NADCA standard 1992-01

(B) Assessment, Cleaning and Restoration (ACR) of HVAC Systems 2002

(C) Assessment, Cleaning and Restoration (ACR) of HVAC Systems 2006

(D) Assessment, Cleaning and Restoration (ACR) of HVAC Systems 2013

Do You Know…16

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This concludes Module 1

History of HVAC Systems Cleaning

History of HVAC Systems Cleaning17

AIR SYSTEMS CLEANING SPECIALIST (ASCS) TO THE NADCA STANDARD ACR

Module 2 HVAC Systems Overview

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WHAT WE’LL LEARN:

Principles of Heating, Ventilation, and Air Conditioning Systems

Types of HVAC Systems

Blueprint Assessment & Symbols

Components of HVAC Systems

HVAC Systems Overview19


Cooling

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The air is cleaned by passing through a filter in the duct that carries it into the air conditioner.


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Filtration

Impingement filters …….

Dry filters ….

Electrostatic filters…

Polarization filters ……………………………

Types of Air Filters


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Ventilation

(the “V” in HVAC) is the process of changing or replacing air in any space to provide high indoor air quality (i.e. to control temperature, replenish oxygen, or remove moisture, odors, smoke, heat, dust, airborne bacteria and carbon dioxide).

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Humidification

A humidifier keeps the air moist inside an occupied space (used mostly during the heating season).

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Dehumidifying

When warm, moist air passes over an air conditioner’s cooling coil, its temperature can fall to a point where it can no longer hold all the moisture it contains. The moisture then condenses on the coil as droplets that may be drained away. This process, called condensation dehumidification, is the most often used in air conditioning.

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Variable Air

Volume

Constant Volume

Dual Duct

Single Zone

Multi Zone

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Variable Air Volume Variable air volume systems maintain thermal comfort by varying

the amount of heated or cooled air delivered to each space, rather than by changing the air temperature.

Types of HVAC Systems27

Variable Air VolumeControl Boxes

Dampers are the main component to be concerned with during cleaning.


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How many zone dampersare in the system in the illustration?


Constant Volume

Constant volume systems, as their name suggests, generally deliver a constant airflow to each space.

Changes in space temperatures are made by heating or cooling the air or switching the air handling unit on and off, not by modulating the volume of air supplied.

These systems often operate with a fixed minimum percentage of outdoor air or with an “air economizer.”


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Constant Volume System

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Dual Duct

The dual duct concept is fairly simple. A fan discharges air which is directed through the cooling coil and/or the heating coil.

There are two separate ducts that feed hot and cold air to the same space.

A dual‐duct mixing box controls the room’s air by modulating the hot & cold air.

They are found in commercial buildings such as hospitals and government buildings.

Take note when you bid them because there can be twice as many ducts.


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Multi Zone System Constant Volume

HVAC11

What makes this multi zone?What about the “T” stats?


This system is a single thermostat multi‐zone system

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Blueprint Assessment & Symbols35

Supply ‐ The symbol is an X

Return ‐ The symbol is a slash

Exhaust – The symbol is 2 slash marks


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Symbol Sheets from SMACNA & ASHRAE


This legend is from a REAL blueprint. The legend is the only way to read this print due to the variance in following ASHRAE or SMACNA symbols.

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M-1

First Floor East

N

Constant Volume

HVAC12

150

This duct is usually metal. Why?

Mat

ch l

ine

“A”

150

150

150 150

150


“Match line" refers to the point or position where another drawing lines up.

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HV

AC

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M-2

First Floor West

Mat

ch l

ine

“A”

What is this symbol and why not the entire duct?

Sound Attenuationmeans to controlthe noise level. Name two ways to do this.


Blue Print Match Line

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outdoor air intake

mixed-air plenum and outdoor air control

air filter

heating and cooling coils

humidification and/or de-humidification equipment

supply fan

ducts

terminal device

return air system

exhaust or relief fans and air outlet

self-contained heating or cooling unit

controls

boiler

cooling tower

water chiller

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Components of HVAC Systems 44

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outdoor air intake

heating and cooling coilsmixed‐air plenum and outdoor air control

air filter


humidification and/or de‐humidification equipment

supply fan

ducts

terminal device (grilles, registers, etc.)


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return air system


Packaged Unitary Equipment

Packaged unitary equipment refers to air conditioning units in which the components are factory assembled into an integrated package that might include controls, fans, filters, a heating coil, a cooling coil, a refrigerant compressor, and a condenser.


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Rooftop Unit (RTU) Packaged Unitary Equipment


Split Systems


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Split Systems

The condensing coil is separatefrom the evaporator coil.

The condensing coil is outside.


Evaporator and Condenser coils are located in separate housings.

Central heating systems obtain their heat from burning fuel in a furnace.

The furnace may heat water, it may turn water into steam (in which case it is called a boiler), or it may heat re‐circulated room air.

These fluids are then the medium used to distribute the heat through the various rooms of the building.

Gas Furnace


TheMOST common types of fuel consumed in modern residential HVAC systems are natural gas, propane, and oil.

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Oil Furnace Furnaces create heat by burning fuel

(gas, oil, or propane). When the fuel burns, it generates hot gasses which travel through curved metal tubing called a heat exchanger. As air passes over the heat exchanger, it absorbs heat from the hot metal surface. The heated air is then circulated through ducts to warm your home or place of business. Meanwhile, the gasses (combustion air) that are created by the burning fuel are released outside through a metal or plastic vent pipe.


Mechanical System Components ‐ Coils Reheat coils – Evaporator coils – Condensing coils

Heating and cooling coils are placed in the airstream to regulate the temperature of the air delivered to the space

In general, the copper rows determine the coil depth for cleaning

Not all coils are cleanable

When cleaning electrical resistance coils in a duct system, it’s important to make sure the power source is de‐energized and avoid using water for cleaning.


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Mechanical System Components ‐ Drain Lines Usually a drain pan and line have the highest amounts of

contaminationwhen compared to all other system components.


Mechanical System Components – Fans

The unique characteristic of Forward Curved fans is that they transfer large volumes of air for a minimum wheel diameter. Therefore, they are used when space requirements are a primary consideration.

These blades commonly lose balance clips.

These wheels are by far the most common and are in most residential units

Courtesy Process Equipment


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The Backward Inclined Flat Fan has some of the characteristics of the airfoil fan ‐ its efficiency is relatively high.

A backward inclined fan has a non‐overloading characteristic. This means that the horsepower required by the fan actually decreases when the flow rate increases past a certain point.

Courtesy Process Equipment



Axial fans are suitable for large quantities of air at low pressures. They produce very little noise and are found in return air ducts. When compared with centrifugal fans, the axial fans offer the following advantages:

Reduced space requirements.

Shorter ducts, thus lowering the cost of the system.

These fans are of the easiest to clean.

Note: This fan can easily become unbalanced while cleaning.


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• Metal Ducts are the most durable and can be cleaned aggressively. Metal is also non‐porous, which means it will not absorb moisture.

• Flex Ducts have a foil exterior reinforced with fiber scrim. Not all flex lines can be cleaned.

• Spiral Ducts are non‐porous and are usually found in medium and high pressure systems.


Spiral High Pressure Duct

Mechanical System Components ‐ Duct Types

Flexible

Metal


• Fibrous Glass duct board has exposed fibrous glass insulation on the interior. Fibrous glass can be penetrated by moisture. Moldy, impregnated fibrous glass ducts should be removed and replaced.

• Double wall lined duct has an inner and outer metal surface that has fiberglass sandwiched between both metal layers. DW Lined will be porous if not continually sealed on the inside.

• Concrete/Transitecan be prone to moisture intrusion.


Ductboard

Double WallTransite

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Double walled ducts are usually found in high velocity air ducts. They are insulated ducts, but are metal on the inside so they can be aggressively cleaned.

High pressure air ducts are very noisy if there is no sound attenuator. You will find these attenuators common in high pressure spiral duct systems.



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Double wall lined

Sound Attenuator

Designed to reduce noise in the ducts.

Mechanical System Components – Turning Vanes

Turning vanes require multiple access points and

care in cleaning

Fiberglass vanes can be very fragile

Primary function is to reduce static pressure loss

in a duct system

Are rarely found in high pressure systems


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Mechanical System Components ‐ Turning Vanes Damaged and missing turning vanes.


Mechanical System Components ‐ Heat Recovery Wheels

A rotary heat recovery wheel exchanges heat and moisture between adjacent exhaust and outside air makeup ducts by providing a moving heat transfer medium between the two. As portions of the wheel are exposed to the conditioned exhaust air, the wheel media absorbs heat (winter operation) or is cooled (summer operation). As that portion of the wheel then rotates into the outside air makeup stream, it either preheats (winter operation) or pre‐cools (summer operation) this stream using the energy gained/lost from the exhaust stream.

What happens when this wheel becomes contaminated with debris?

As the wheel becomes dirty, its ability to transfer heat decreases.

How do we clean these devices?


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Source - Engelhard/ICC Corp.



Source - Engelhard/ICC Corp.

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Attention should be paid to vents, grilles, registers and diffusers …consider the following: Special attention should be given to determining whether ducts are

contaminated only where specific problems are present, for example: water damage or biological growth observed in ducts; debris in ducts that restricts airflow; or dust discharging from supply diffusers.


Note: Dirt streaks around supply diffusers that are not caused by a dirty ventilation system could be caused by dirty room air at the diffuser.

Attention should be paid to vents, grilles, registers and diffusers …consider the following: Some diffusers are built directly into other components such as

light fixtures. Can they be cleaned?

What are the differences between vents, grilles, registers and diffusers?

What is a linear diffuser?


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What about vents that have been painted over?

If you encounter vents that have been painted over during an HVAC system cleaning project, the usual course of action would be to inform the owner that a razor knife will be used to cut the paint before continuing with cleaning.

Practical Application69

Mechanical System Components ‐ HEPA Filtration

When we have a HEPA filter certified, we do so using a test called the DOP test. The test does the following:

Tests to see if the filter is intact

Tests to see if the level of 99.97% to .3 microns can be met

Certifies the filter using an independent third party


HEPA stands for high efficiency particulate air. HEPA filters eliminate 99.97% of all particles as small as 0.3 microns.

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Mechanical System Components ‐ Filtration

HEPA filters are a basic element used to protect the indoor environment during cleaning. Therefore, all equipment exhausted inside must first be HEPA filtered.

Note: Efficiency on many filters will first increase with initial loading then will drop off. Why?


According to SMACNA ‐ Filtration

Factors that help determine the type of filtration used in an HVAC application include:


Particle density in the air and particle size

Allowable filter resistance in the HVAC system

Cost effectiveness of the filter

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See NADCA’s ASCS to the ACR Standard Manual for additional information about:

Principles of Heating, Ventilation,

and Air Conditioning Systems





If your vacuum exhausts inside, what type of filter should you use?

(A) Pleated Filter

(B) HEPA Filter

(C) Electrostatic Filter

(D) Impingement Filter

Do You Know…74

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This concludes Module 2

HVAC Systems Overview


AIR SYSTEMS CLEANING SPECIALIST (ASCS) TO THE NADCA STANDARD ACR

Module 3 - Protecting Health and Safety of Occupants and Building

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WHAT WE’LL LEARN:

Preliminary Recommendations on HVAC Cleaning

HVAC Systems and Indoor Air Quality

HVAC Systems and Mold

Preparing and Protecting the Site

Avoiding Cross Contamination

Security Issues and Responsibilities

Protecting Health and Safety of Occupants and Building

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Duct cleaning should be scheduled during periods when the building is unoccupied (if possible).

Negative air pressure that will draw pollutants to a vacuum collection system should be maintained at all times in the duct cleaning area to prevent migration contaminants.

If it is determined that the ducts should be cleaned, careful attention must be given to protecting the ducts.

Duct cleaning is performed with well-controlled brushing or air washing of duct surfaces.

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Only HEPA filtered vacuuming equipment should be used if the vacuum collection unit is inside the occupied space.

If biocides are to be used, then select only products registered by EPA for such use. Use the products according to the manufacturer’s directions, and pay careful attention to the method of application. (See NADCA White Paper on Chemical Applications in HVAC Systems)

Careful cleaning of coils and drip pans can reduce microbiological pollutants.

Water-damaged or contaminated porous materials in HVAC systems should be removed and replaced.

After the duct system has been cleaned and restored to use, a preventive maintenance program will prevent the recurrence of problems.

What is Indoor Air Quality?

Indoor air quality (IAQ) in I‐BEAM refers to the quality of the air inside buildings as represented by concentrations of pollutants and thermal conditions (temperature and relative humidity) that affect the health, comfort, and performance of occupants.

Other factors affecting occupants, such as light and noise, are important indoor environmental quality considerations, but are not treated in I‐BEAM as core elements of indoor air quality.

HVAC Systems and Indoor Air Quality80

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Ventilation

All occupied buildings require a supply of outdoor air. Depending on outdoor conditions, the air may need to be heated or cooled before it is distributed into the occupied space.


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

The Society and its members focus on building systems, energy efficiency, indoor air quality, refrigeration and sustainability within the industry.

HVAC Systems and Indoor Air Quality

American Society of Heating, Refrigerating and Air Conditioning Engineers

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ASHRAE 62‐2010 is intended to assist professionals

in the proper design of ventilation systems for buildings

Important features of ASHRAE 62‐2010 include:

A definition of acceptable air quality

A discussion of ventilation effectiveness

The recommendation of the use of source control

through isolation and local exhaust of contaminants

Recommendations for the use of heat recovery ventilation

A guideline for allowable carbon dioxide levels

Appendices listing suggested possible guidelines for common indoor pollutants

Standard 62‐2010 ‐ “Ventilation for Acceptable Indoor Air Quality”



ACR, The NADCA Standard – Assessment, Cleaning, and Restoration of HVAC Systems includes a section on Project Evaluation and Recommendation.

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“Conducting an indoor environmental impact survey”

When contamination is identified or other criteria triggering cleaning are met, it is highly recommended that a project evaluation take place prior to initiating cleaning work. The project evaluation includes three steps:

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3) conducting an indoor environmental impact survey

2) identifying the type of contamination present in the HVAC system

1) determining the building usage by classification(In instances where more than one building classification applies to an area, the most stringent classification will apply)

Furniture and Flooring

Furniture and flooring in areas to be cleaned should be covered with protective coverings to prevent contamination

Flooring should be well protected as some mechanical systems cleaning equipment can be large and may be moved through the facility. Floor preparations can vary from light protective coverings to cardboard to plywood sheeting depending on the facility and type of flooring

Building occupants may be more aware of dirt and dust accumulation after mechanical systems cleaning

Preparing and Protecting the Site86

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Building Fire Safety & Security

Prior to the start of any HVAC cleaning project, both the client and the contractor should review the existing safety and fire evacuation procedures for the facility.

Most HVAC systems have fire alarms built into the ductwork designed to detect smoke and heat. These systems are commonly disconnected prior to the cleaning process to prevent false alarms.

The facility manager is responsible for deactivating in‐duct smoke detectors prior to cleaning.

Preparing & Protecting the Site87


Containment strategies and engineering controls that were discussed earlier in this module are in part, designed to prevent cross contamination.

Assess if equipment brought to a job will create the potential for cross contamination. Equipment should be cleaned and assessed before and after every job.

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Mechanical cleaning shall incorporate the use of vacuum collection devices that are operated continuously during cleaning.

Vacuum collection devices shall be used to prevent cross contamination of debris and/or to convey and capture debris dislodged during the mechanical cleaning process.

Collection device must be hooked up and running before performing any work on the air ducts, including before you remove the registers.


ACR, The NADCA Standard ‐ Engineering Controls for HVAC Cleaning and Restoration Projects

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In cases of severe microbial growth, or where hazardous substances are known to be present within the HVAC system, or on projects taking place within healthcare facilities, there shall be an on‐site hygiene/integrity inspection of vacuum collection equipment prior to commencement of work. The building owner or his representative should conduct the inspection.

Avoiding Cross Contamination90

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Contamination from tools and equipment

How does contamination occur through zoning devices and cable drives?

When a collection device exhausts within the building envelope, it must be equipped with HEPA filters. This is directly from the standard. What does it mean?

If you are inspecting the HEPA filter in a vacuum collection device and notice the aluminum fins are bent, you should next inspect the HEPA filtration media.


ACR, The NADCA Standard – Decontaminating Remediation Equipment

Tools, equipment and instrumentation brought onto the work site shall be clean and must not introduce contaminants into the indoor environment or HVAC system.

Unfortunately, residential cleaners regularly cross contaminate with plastic, cardboard, rags and foam blocks.

Foam blocks used in zoning are most‐likely to cross‐contaminate.


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Removal and Disposal of Contaminated Materials

All contaminated materials removed from the HVAC system shall be properly contained to prevent cross‐contamination. Removed debris should be double‐bagged and sealed in 6‐mil polyethylene bags.

Any activity requiring the opening of contaminated vacuum collection equipment on‐site, such as servicing or filter maintenance, shall be performed in a negatively pressurized containment area or outside the building.


Partial Envelope Containment

Cross Contamination Engineering

Room pressure differentials

HEPA filtered equipment

Plastic barriers

80’

50’

M

M


HEPA filtered negative air

Air Monitor

Positive Pressure

Negative Pressure

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Security Issues and Responsibilities

Along with protecting the indoor air quality of the facility, the mechanical systems cleaner is tasked to note unusual security conditions and address them with the owner.

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This concludes Module 3Protecting Health and Safety of Occupants and Building

Protecting Health and Safety of Occupants and Building

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Module 4 – Performing the Cleaning


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WHAT WE’LL LEARN:

Preliminary Determination Inspection or Assessment

Protecting Health & Safety

Engineering Controls

Work Practices

Performing the Cleaning98

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The term “HVAC system cleaning” is used exclusively throughout this document instead of the common term “air duct cleaning.” The requirements of this document encompass the entire HVAC system and its components.

To ensure optimum system performance and environmental conditions, the entire HVAC system should be maintained at the highest cleanliness levels possible as described in this Standard.


The system is contaminated with an accumulation of particulate;

Microbial contamination conditions have reached either Condition 2 or Condition 3;

HVAC system is discharging visible dirt or debris into the conditioned space;

The HVAC system has been contaminated as a result of fire, smoke, or water damage;

Deterioration of fiberglass duct liner, duct board, or other porous components;

When the system has become contaminated with construction debris or dust;

As part of a pro‐active indoor air quality management program.


ACR, The NADCA Standard‐ Determining the Need for HVAC Cleaning

The NADCA Standard ACR makes recommendations on when to clean HVAC systems based upon indications/conditions discovered through proper HVAC cleanliness inspection or building history.

Some examples of such conditions* include:

*See ACR for additional conditions

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ACCA – Standard 6 Restoring the Cleanliness of HVAC Systems

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Appendix A‐1 MAINTENANCE AWARENESS

Failure to maintain proper conditions of cleanliness in HVAC systems and carelessness in servicing or repair operations have been linked to an increased likelihood of HVAC system failure, reducing the life expectancy of the equipment, impacting the indoor air quality of the areas being service by the equipment, and impacting the energy efficiency of the HVAC systems


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ACR recommends that HVAC systems be cleaned when a proper HVAC cleanliness inspection indicates that a newly installed component or duct has been contaminated with construction and/or other duct and debris.

New Construction

SMACNA’s Duct Cleanliness for New Construction Guidelines provides requirements regarding proper storage of job site duct materials to prevent damage, dust & debris.

Source: Pg. 2.1 (Section 2 ‐ General Requirements)

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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.


Inspections

ACR, The NADCA Standard – Inspections

Visual InspectionWhen performing an initial inspection of an HVAC system, visual inspection should be performed first.

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When to Perform an Inspection

When a customer asks for confirmation that the ducts in their building are dirty, according to the NADCA ACR Standard, conducting a visual inspection within respective areas of the entire HVAC system is the best method for making that determination.


Inspections


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Inspections

Inspections are an important component of any HVAC cleaning and restoration project.

HVAC inspections shall be performed to determine:

the need for cleaning

the scope of work

engineering controls

safety measures

tools and equipment necessary to perform a cleaning and restoration

project


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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.


Keep in mind…Various methods of inspection (i.e. robotic cameras, borescope) can have the potential to cause cross‐contamination of the system. Make sure appropriate engineering controls are used.

Inspections


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ACR, The NADCA Standard – Inspection Schedule Table 1

The inspection intervals specified in Table 1 are minimum recommendations.

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

Table 1HVAC Cleanliness Inspection Schedule

(Recommended Intervals)


Recommended inspection schedule for major HVAC componentswithin different building use classifications:

If the inspection of the air handling unit reveals contamination, then supply and return ductwork must be inspected at that time rather than in accordance with the intervals specified in Table 1.

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Supply fan to move air through the distribution system

Heating and/or cooling coils to adjust temperature of the Air Filters to remove particulate matter from the air

Associated inlet and outlet dampers to control ow of air

AHU Typical

Components

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AHU Inspections

filters and air bypass

heating and cooling coils

condensate pans

condensate drain lines

humidification systems

acoustic insulation

fans and fan compartments

Dampers

door gaskets

general unit integrity


The air‐handling unit (AHU) cleanliness inspection should consider all components within the unit, including:

If inspection of the air‐handling unit reveals contamination, then supply and return ductwork must be inspected at that time rather than in accordance with the intervals specified in Table 1 of the HVAC Cleanliness Schedule.

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A commercial Air Handling Unit (AHU) generally consists of supply fan, coil, filters, and outlet and inlet dampers.

NFPA 90 A – Standard for the Installation of Air‐Conditioning and Ventilating Systems


According to NFPA 90‐A:

Cleaning should be undertaken whenever an inspection indicates the need.

A contributing cause of fires in HVAC systems is due to failure to maintain system cleanliness.

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Asbestos


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If asbestos is suspected and/or encountered, it is very important that you cease work and notify the client of the condition.

A professional will need to confirm if it is asbestos and a licensed asbestos contractor must be recommended to handle the project.

Lock Out/Tag Out


Lock Out/Tag Out* is an OSHA procedure for locking out energy sources while working on air handlers. This is an important procedurethat will protect employees and the employer.

*The NADCA Safety Manual offers extensive guidance on the proper use of Lock Out/Tag Out procedure.

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Energy Control Program

The employer's primary tool for providing protection under the standard is the energy‐isolating device, which is the mechanism that prevents the transmission or release of energy and to which locks or tags are attached.

This device guards against accidental startup or the unexpected re‐energization of machines or equipment during servicing or maintenance.

Lock Out/Tag Out

Protecting Health & Safety113

Make sure that locks or tags are removed ONLY by those employees who attached them. (In the very few instances when this is not possible, the device may be removed under the direction of the employer provided that he or she strictly adheres to the specific procedures outlined in the standard);

Notify affected employees after removing locks or tags and before starting equipment or machines.

1 Lock per worker is the rule.

Lock Out/Tag Out

Remember…


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Electrical hazards

Circuit protection devices The ground‐fault circuit interrupter, or GFCI*, is designed to shut off

electric power within as little as 1/40 of a second. It works by comparing the amount of current going to electric equipment against the amount of current returning from the equipment along the circuit conductors. The GFCI is used in high‐risk areas such as wet locations and construction sites.

Drop lights are a hazard when working with water. Fluorescent drop light bulbs are safest when using water‐pressure cleaning inside an air handler unit.

*NADCA’s Intro to HVAC System Cleaning & the NADCA Safety Manual provide further guidance.


Confined Space

When working inside a confined space, health and safety concerns shall be a priority. The duct support system, internal components, configuration and confined space concerns shall be evaluated for safety.



When a technician is required to enter ductwork for cleaning, it must first be considered if the duct is capable of safely carrying the weight of the technician.

It is recommended that a Certified Safety Professional be consulted as needed.

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Respiratory ProtectionOSHA respiratory protection

Identification of filters, cartridges, and canisters. The employer shall ensure that all filters, cartridges and canisters used in the workplace are labeled and color coded with the NIOSH approval label and that the label is not removed and remains legible.

MAGENTA = HEPA Filter


N95 respirator type would be the minimum acceptable respirator type that workers should use while cleaning a duct system.

Personal Protective Equipment (PPE)

Personal protective equipment should not be used as a substitute for engineering, work practice, and/or administrative controls.

Personal protective equipment should be used in conjunction with these controls to provide for employee safety and health in the work place.

Personal protective equipment includes all clothing and other work accessories designed to create a barrier against workplace hazards.

Personal Protective Equipment (PPE) on all jobs is required by OSHA.

*NADCA’s Safety Manual provides further guidance on PPE.


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Hazard CommunicationsACR, The NADCA Standard – Work Plans

ACR states the Work Plan shall include Safety Data Sheets/Material Safety Data Sheets (SDS/MSDS) for all chemical products to be used on the project.

“Safety data sheet/Material safety data sheet” (SDS/MSDS) is written or printed material concerning a hazardous chemical.

Employers are responsible for informing employees of the hazards and the identities of workplace chemicals to which they are exposed.

MSDS/SDS deals with container labeling issues, exposure limits, emergency and first aid procedures, precautionary measures & more and should be stored on the job site.


Cross Contamination


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

Mechanical cleaning shall incorporate the use of vacuum collection devices that are operated continuously during cleaning. Vacuum collection devices shall be used to prevent cross contamination of debris and/or to convey and capture debris dislodged during the mechanical cleaning process.


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Other Safety Issues…

There are many other safety issues that must be addressed on HVAC Cleaning projects.

Be sure to refer to NADCA’s Safety Manual for a thorough review of these issues.


Where is the safest place to walk when working in a fully exposed attic?

On top of the joists!

121


Engineering controls shall be used to ensure worker safety and health, and to prevent cross‐contamination.


Engineering controls may include, but are not limited to:

122

source control

isolation barriers

pressure differentials

dust suppression methods

HEPA vacuuming and filtration

detailed cleaning

temperature and humidity control

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Source Control is an engineering control and a term used to describe the lowest level of containment in the American Conference of Governmental Industrial Hygienist’s (ACGIH) Bioaerosols Assessment and Control book.


In the photo above, flex tube is connected to the return side of a residential air handling unit to create a negative pressure in the return air portion of the system. To create a good negative pressure, you must also seal off all but one opening to the return side of the system and seal off the air handling unit.

Source Control

123

Isolation barriers are commonly constructed using polyethylene that is 6 mils thick.

Fire retardant poly is preferred.

Various types of tape and spray adhesive are used to make an airtight seal.

Isolation Barriers

On some projects Air Filtration Devices are placed inside the containment and exhausted outdoors to create pressure differentials.

Engineering Controls124

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Pressure differentials can be verified visually by observing poly billowing inward or by using a pressure differential monitor.

Engineering Controls125

Dust Suppression ‐Methods such as misting with an airless sprayer are common. An example of using dust suppression is low pressure flushing of coils.

HEPA Vacuuming & Filtration‐ All work done on HVAC cleaning projects should be done using HEPA equipped tools, vacuums, etc.

Detailed Cleaning ‐ Performing cleaning in a detailed or white glove manner is in itself an engineering control.

Temperature & Humidity Control ‐ During HVAC cleaning, system should be shut down. Use of portable air conditioning and heating equipment and dehumidifiers may be appropriate on certain jobs.

Sanitary Approach ‐ Continuously bagging debris and HEPA vacuuming areas while cleaning to ensure debris does not get spread around an area.


Other

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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.

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.

Negative Pressure Requirements: A continuous negative pressure shall be maintained in the portion of the HVAC system being cleaned in relation to the surrounding indoor spaces. The negative pressure shall be verified at representative locations during the cleaning process.



Remember…

127

Accessing and Closing the System

ACR, The NADCA Standard – Cleaning & RestorationService openings may be needed to perform assessment, cleaning and restoration (ACR) procedures.

ACR provides minimum requirements including:

Service openings shall:

not degrade the structural, thermal, or functional integrity of the system;

not hinder, restrict, or alter the airflow within the air duct;

not be made in flexible ductwork;

be created in a manner that allows for proper closure;

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

Be sure to review the ACR for additional requirements.

Work Practices128

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What is Mastic?Pasty material used to caulk, seal or cement gaps and cracks in air duct connections and joints to prevent air leakage.

Mastic is used for sealing openings in a duct and for sealing fiberglassinsulation penetrations.

ACR, The NADCA Standard ‐ Cleaning and Restoration

It is recommended that service panels used for closing service openings be sealed with gaskets, caulking, mastic or tape.

Work Practices129

Leaks in the supply ductwork of a residential HVAC system that is located in an attic willMOST likely cause which of the following?

(A) positive pressurization of the occupied space.(B) balanced pressurization of the occupied space.(C) negative pressurization of the occupied space.(D) cleaner air for the occupied space.

Practical Application…130

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Mastic

Work Practices131

What about the size of closures?

ACR, The NADCA Standard – Cleaning & Restoration

Panel shall overlap the ductwork surfaces by a minimum of 1” on all sides

12 Inch

10 Inch

Work Practices132

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What type of metal do we need for closures?

ACR, The NADCA Standard – Cleaning & Restoration

Service panels used for closing service openings in the HVAC system shall be of an adequate gauge so as to not compromise the structural integrity of the duct.

The gauge of the duct access door shall be based on the pressure class of the duct system and shall be installed according to manufacturer’s specifications.

Remember to patch a hole with equal gauge or stronger.

Work Practices133

Sheet Metal Ductwork

Access Panel

Access Door

Work Practices134

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Metal Duct with External Insulation

Non Insulated

Externally Insulated

Work Practices135

Access and Closure Tools

Work Practices136

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Metal Ducts with Fiberglass Liner

Insulated Access Door

Insulated Access Panels

Work Practices137

Metal Ducts with Elastomeric Liner

Work Practices138

Mold resistant, contains EPA-registered antimicrobial product protection

Supports LEED, meets ASHRAE criteria

No formaldehyde, Low VOC and No Fibers

Acoustic, excellent sound absorption and noise blocking

Longer lasting, more durable, easier to clean than fiberglass

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Fiberglass Duct Board

Make pumpkin cut

Reuse cut out

Reseal with UL‐181A Tape (scrim faced?)

Work Practices139

What type of tool do we need for fiberglass duct board openings?

The service openings should be made using a straight knife to cut a converging 45 degree angle on all four sides.

Work Practices140

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Fiberglass Ductboard Access Tools

Work Practices141

Insulated flex duct

Disconnect to clean and reinstall following local codes

Work Practices142

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Ductboard Closure Tools

Work Practices143

This tool is used only to make straight cuts

Hand snips are used to cut circle or oval holes in the absence of a nibbler

This sheet metal Nibbler is capable of cutting straight, round or oval holes and

generates lots of small pieces of metal

Access And Closure Tools

Work Practices144

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Tool selection skills in the fieldConsider the following:

The Fin Comb is designed to straighten / clean thedelicate condenser and evaporator fins to ensuremaximum system efficiency.

Work Practices145

If air goesin here?

Process selection tools in the field

Consider the following: Electric or Fuel?

What comesout here?

Work Practices146

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Specialty Tools

What is the name for these tools? What is the purpose for each of these devices? What is the best tool to use for coating application? What tool is best for microbiocide application?

Work Practices147

M-1First Floor Residential Home

NWhat happens if we cover all the ducts and energize the truck?

What is the minimum number of connection points that will need to be cleaned?

Purpose of the truck is to collect and contain debris

Mat

ch l

ine

“A”

HVAC12

A

B

C

Work Practices148

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Ductboard System

M-1First Floor Residential Home

N

Mat

ch l

ine

“A”

HVAC12

Work Practices149

Process selection skills in the field Consider the following:

ACR ‐ Cleaning & Restoration Procedures

Type 2 Coil Cleaning (Wet Cleaning):

Wet cleaning processes using pressurized water and chemical agents are normally required for coil cleaning.

Mechanical cleaning using contact vacuuming and/or air sweeping is an acceptable method for cleaning in‐duct single and two‐row heating and/or cooling coils provided that no microbial contamination exists on the coil. In‐duct coils with three or more rows may require wet process cleaning.

Work Practices150

The most effective technique for cleaning an evaporator coil is by pressure washing. More complete coil cleaning results in significant energy savings.

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Microbiocide Information from the EPAACR, The NADCA Standard ‐ Cleaning & Restoration Procedures

Remediation of Mold and Other Biological Contamination:

Sterilizers (Sporicides): Used to destroy or eliminate all forms of microbial life including fungi, viruses, and all forms of bacteria and their spores. Spores are considered to be the most difficult form of microorganism to destroy.

Disinfectants: Used on hard, inanimate surfaces and objects to destroy or irreversibly inactivate infectious fungi and bacteria but not necessarily their spores.

Work Practices151

Microbiocide Info from the EPAACR, The NADCA Standard ‐ Cleaning & Restoration Procedures

Sanitizers: Used to reduce, but not necessarily eliminate, microorganisms from the inanimate environment to levels considered safe as determined by public health codes or regulations.

Work Practices152

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Microbiocide Info from the EPAACR, The NADCA Standard ‐ Cleaning & Restoration Procedures

Biocides: Chemicals that kill living organisms. A biostat is a chemical thatinhibits the life processes of living organisms without actually killingthem.

Work Practices153

• Clean = removal of all visible dust, soil and any other foreign material.

• Sanitize = reduce microbes on surfaces to a safe or relatively safe level.

• Decontaminate = remove disease-producing microbes rendering safe for handling.

• Disinfect = kills or destroys nearly all disease-producing organisms, except spores.

Work Practices

TERMINOLOGY

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Work Practices155

CATEGORIES OF ANTIMICROBIALS

Least Efficacious Most Efficacious

Sanitizer Disinfectant Sterilant

High‐level disinfection

Intermediate level disinfection

Low‐level disinfection

Germicide = chemical that destroys microorganisms. Used to kill disease causing microorganisms, but not spores

Fungicidal kills fungi

Tuberculocidal kills Mycobacterium tuberculosis

Work Practices

Antiseptics are used on skin and Disinfectants are used on objects

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Work Practices157

Virucidalkills viruses.

Sporicidalkills microbial

spores, especially bacterial spores.

Bacteriostaticinhibits growth of bacteria but does

not kill them. Bactericidal kills

bacteria

Sterilizedestroys all forms of microbial life

including bacteria, fungi,

viruses and spores

Sterilizers (Sporicides)

Disinfectants

Sanitizers

Deodorizers

Who is responsible for applying these products?

Do we need to have a registered deodorizer?

According to the EPA, what is the difference between Registered and Approvedmicrobiocides for duct systems?

Work Practices

Further information can be found in the NADCA Position Paper on Chemical Product Applications in HVAC Systems

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Understanding the EPA’s responsibility so you don’t confuse the consumer

Consider the following:

Microbiocides – Label Confusion

The manufacturer of a microbiocide must strictly identify the EXACT procedure for application of the product and the amount of time the product must remain on the surface

The EPA does not write ANY instructions for the label. They only verify the label is correct with respect to killing microorganisms.

Work Practices159

Important: When applying antimicrobials and cleaning agents, you must minimize employee and occupant exposure.

Cleaning Techniques by Air Duct Type

Metal ductwork with NO internal liner can withstand very aggressive brushing techniques.

For example, a rotating rigid bristle brush would be an appropriate tool to loosen the particulate in a sheet metal air duct with thick layers of dust & debris.

Work Practices160

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Containment Strategies

Fundamental understanding of why so much time is spent on use of containment equipment …consider the following:

The goal of any containment strategy is to move particulate substances and other debris in a controlled manner from the point of origin to the point of capture (i.e., the vacuum collection device) without allowing the escape of debris outside the work area to prevent contamination of indoor spaces.

Work Practices161


Fundamental understanding of why so much time is spent on use of containment equipment…consider the following:

ACR – Environmental Controls

Level 1 Containment

Negative Pressure – The HVAC system, 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.

Work Practices162

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Level 1 Containment

Protective Coverings – Clean, protective coverings must be used within each work area. Protective coverings must extend beyond the work area to provide protection of flooring, equipment, and furniture whenever necessary.

Work Practices163




Level 1 Containment

Cleaning Equipment – Inlet openings on all vacuum collection devices and negative air machines must be properly sealed during transport and when the equipment is not in use. Vacuum hose openings must be sealed during transport. All tools, equipment, and equipment components that enter the HVAC system from an occupied space must be wet‐wiped, HEPA vacuumed, or sealed in a disposable polyethylene bag during removal from the HVAC system.

Work Practices164

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Fundamental understanding as to why so much time is spent on use of containment equipment…consider the following:


Level 1 Containment

Cross Contamination Control – Suitable provisions must be made to control contaminant discharge from the HVAC system and cross contamination into occupied space during the cleaning process. This may require temporary sealing of existing duct joints, seams and other system components.

Work Practices165




Level 2 Containments (Temporary Barriers)

All level 1 containment requirements apply to Level 2 Containments. Temporary barriers shall be constructed.

Work Practices166

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ACR – Engineering Controls

Level 3 Containment: A containment with a single

chamber decontamination unit.

All level 1 and level 2 containment requirements

apply to Level 3 Containments. Temporary

barriers shall be constructed with a single

chamber decontamination unit.

Work Practices167

Fiber Glass cleaning methods

How to explain to the customer the primary methods of cleaning fiberglass, and why…consider the following:

ACR – Cleaning & Restoration Procedures

Cleaning Fibrous Glass Duct System Components:

It is highly recommended that fiber glass thermal or acoustical insulation elements present in any equipment or ductwork be thoroughly cleaned with HEPA contact vacuuming equipment, or other appropriate equipment.

Work Practices168

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169

What Is NAIMA? NAIMA (North American Insulation Manufacturers Association) is a

trade association of North American manufacturers of fiber glass, rock wool, and slag wool insulation products. For Fiberglass questions, they are the authority.

Work Practices

NAIMA Standards:NAIMA – Cleaning Fibrous Glass Insulated Duct SystemsNAIMA – Fibrous Duct Construction Standards

Stick pin fasteners should be used when installing or repairing duct liner.

When fiberglass insulation is damaged or deteriorating it is recommended to remove and replace.

Mechanical Cleaning Methodology

Cleaning Agents and Coatings

Antimicrobial agents shall only be applied if active fungal growth is reasonably suspected, or where unacceptable levels of fungal contamination have been verified through testing.

Application of any antimicrobial agents used to control the growth of fungal or bacteriological contaminants shall be performed after the removal of surface deposits and debris.

Review the NADCA Position Paper on Using Chemical Products In HVAC Systems.

Work Practices170

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Cleaning Agents and Coatings

When used, antimicrobial treatments and coatings shall be applied in strict accordance with the manufacturer’s written recommendations and EPA registration listing.

Antimicrobial coatings shall be applied according to the manufacturer’s written instructions. Coatings shall be sprayed directly onto interior ductwork surfaces, rather than “fogged” downstream onto surfaces.

Work Practices

Mechanical Cleaning Methodology171

Potential Long Term Chemical Release

In no case shall an encapsulant, coating or adhesive be applied prior to, or in lieu of, source removal mechanical cleaning of contaminants. Encapsulation is permitted as a temporary measure on porous materials.

Work Practices172

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“Some research suggests that cleaning heating and cooling system components (e.g., cooling coils, fans and heat exchangers) may improve the efficiency of your system, resulting in a longer operating life, as well as some energy and maintenance cost savings.”

Work Practices

According to the EPA’s “Should You Have the Air Ducts in Your Home Cleaned”…

173

Note: This document was developed in 1998 and is up for review and edit by the EPA. An updated edition is expected to be developed.

A clogged evaporator coil reduces air flow through the coil, thus causing the compressor motor to consume more energy.

Work Practices

According to the Federal Energy Management Program “Fact Sheet”…

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Evaporator coil reconditioning involves both coil inspections and coil cleaning.

An inspection always begins the coil reconditioning process.

Work Practices

Coil Reconditioning

175

The substances impacted on the evaporator coil help determine the initial selection of the cleaning protocol. Evaporator coil cleaning is broken into two (2) categories known as Types. Evaporator coil reconditioning will utilize Type‐1 or Type‐2 cleaning methods.

Type 2Type 1

Work Practices

Coil Reconditioning

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Both coil reconditioning types require usage of HEPA filtered negative air machines when exhausting within a facility. When machines are externally exhausted HEPA filters are recommended but not required. Type 2

Type 1

HEPAHEPA

Work Practices

Coil Reconditioning

177

Negative air machines must operate continuously during the complete coil reconditioning process.

The evaporator coil must be physically isolated from the duct system during the cleaning process to ensure disrupted particulate does not migrate to, or redeposit on, unintended areas.

Work Practices

Coil Reconditioning

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Visual observations of coil surfaces can be misleading. Therefore a static pressure drop should be obtained before and after the cleaning process to demonstrate the effectiveness of such efforts.

This type of measurement, which can be performed using a Magnehelic gauge, or manometer, is a more accurate indicator for the presence of debris that has either been removed or remains within the coil.

Work Practices

Measuring the Effectiveness of Cleaning Efforts

179

Contaminated Coils ‐ Dry Cleaning

Contact vacuuming of impregnated surfaces is the most appropriate method when we begin to clean heavily contaminated evaporative coils

How should we contact vacuum the surface?

Work Practices180

Always vacuum in the direction of the coil fins!

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Coil Cleaners for Wet CleaningACR, The NADCA Standard ‐ Cleaning & Restoration Procedures

Type 2 Coil Cleaning (Wet Cleaning):

Coil surfaces shall be thoroughly cleaned using methods that will render the coil visibly clean. Cleaning methods shall not cause any appreciable damage to, displacement of, inhibition of heat transfer, or erosion of the coil surface or fins, and shall conform to coil manufacturer recommendations when available.

All chemical cleaner residue shall be thoroughly rinsed from the coiland other HVAC surfaces.

Wet cleaning is the most effective cleaning method for evaporative coils

Work Practices181

Contaminated Coils ‐Wet Cleaning


Type 2 Coil Cleaning (Wet Cleaning): Type 2 cleaning methods are appropriate for removing adhered debris on all coil, drain pan and drain line surfaces.

Work Practices182

After performing Type 2 coil cleaning, if there is still debris on the coil, repeat the Type 2 process.

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Coil Cleaners and pH value

Alkaline Cleaners

Grease and oil‐based soils are responsive to high alkalinity. These types of soils are often encountered on evaporator and other internal air‐handler surfaces. The oils come from human and animal skin flakes, cooking, and other inside sources.

Work Practices183

Coil Cleaners and pH value

Acidic Cleaners

Particulates, smoke, and other environmental soils tend to be responsive to acidic cleaners (sodium hydroxide). This makes acid type cleaners especially popular in exterior applications.

Work Practices184

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When you encounter a limited access evaporator coil in an HVAC system:

All portions of each coil assembly must be cleaned. Both upstream and downstream sides of each coil section must be accessed for cleaning. Where limited access is provided between close proximity or zero‐tolerance heating and cooling coils in an AHU, cleaning will require coil removal and/or replacement.

Work Practices185

Sound Attenuators

Perforated devices are treated the same as a porous duct with respect to moisture issues.

Work Practices186

A water pressure washer should not be used for cleaning a perforated sound attenuator and the internal components of perforated sound attenuators are not cleanable.

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Fiberglass cleaning methodsUnderstand which tools fit into the category “agitation devices”

…consider the following:


Cleaning Fibrous Glass Duct System Components:

Mechanical cleaning requires mechanical

agitation devices to dislodge debris adhered

to interior HVAC system surfaces, such that

debris may be safely conveyed to vacuum

collection devices.

Agitation devices may include compressed

air systems, power water wash systems, pneumatic and electric brushes, and hand tools such as brushes.

Work Practices187

The definition of source removal

Comprehend the fundamental meaning of source removal

ACR Definitions

Mechanical Cleaning: Physical removal of contaminants and debrisnot intended to be present, from internal HVAC system surfaces

All airside components must be cleaned according to ACR.

Work Practices188

Source removal is the method of HVAC system cleaning designed to safely extract contaminants from within the HVAC system.

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Proper Sequence –

In accordance with ACCA Standard 6 – Restoring the Cleanliness of

HVAC Systems, Section 5.6:

“Cleaning work should follow the pathway of the HVAC systems designed airflow, beginning at the system's return air intakes. Cleaning should then proceed from return air intakes to the air handling unit, and then out through the supply trunk line, branch runs and discharge points. This work sequence, when properly performed, is designed to reduce the likelihood of cleaned portions of the ventilation system becoming re‐contaminated.”

Work Practices189

Supply DuctAHUReturn Air Intake

Surface Comparison Test

ACR ‐ Cleanliness Verification and Documentation

Description of Method 1 – Visual Inspection

Work Practices

Test Method 1 Protocol: A visual inspection of porous and non‐porous HVAC system components must be used to assess that the HVAC system is visibly clean. An interior surface is considered visibly clean when it is free from non‐adhered substances and debris. If a component is visibly clean then no further cleanliness verification methods are required.

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Surface Comparison Test


Description of Method 2 ‐ Surface Comparison Testing

Work Practices

Test Method 2 Protocol: A vacuum brush shall be attached to a contact vacuum and the device shall be running. The contact vacuum shall be fitted with a 2.5 inch round nylon brush attached to a 1.5 inch diameter vacuum hose.The brush shall be passed over the surface test area four (4) times,with the brush depressed against the surface being tested using light to moderate pressure (as used in routine cleaning).

191

Vacuum Test


Description of Method 3 ‐ NADCA Vacuum Test:

The NADCA Vacuum Test is used for scientifically evaluating particulate levels of non‐porous HVAC component surfaces.

Work Practices192

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NADCA Vacuum Test

ACR ‐ Cleanliness Verification and Documentation Description of Method 3 ‐NADCA Vacuum Test:

A vacuum cassette with filter media is attached to a calibrated air sampling pump and the open face of the filter cassette is passed over two 2 cm x 25 cm openings within the template.

Work Practices193

Template - Visual25 CM

2 CM

25 CM

2 CM

NADCA 100CM TemplateHow do we implement this?

What do we need to be cautious of?

Work Practices194

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Passing Clearance Criteria

Know ACR passing criteria…consider the following:


Passing Criteria for NADCA Vacuum Test: To be considered clean by the NADCA Vacuum Test, the net weight of the debris collected on the filter media shall not exceed 0.75 mg/100 cm2.

Work Practices195

Resetting the System

Know ACR position on resetting the system after cleaning …consider the following:

ACR - Cleaning and Restoration Procedures

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.

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Fire Damper

If during an HVAC system cleaning you encounter a closed fire damper in the supply duct, you should report this to the client and recommend fusible link replacement.

Work Practices197

Equipment Redundancy

Concurrent operation ‐ the redundant equipment must be fully operationalwhile the primary equipment is functioning. Loss of either piece of equipment should not alter the containment, engineering controls or safety protocols of the project to a point less than the minimum requirements.

Non‐concurrent operation ‐ the redundant equipment is not required to be operationalwhile the primary equipment is functioning. The secondary equipment must be wired, contained, isolated, vented, secured, and fully prepared for immediate operation if failure of the primary equipment occurs.

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Post‐Project Report

At the conclusion of the project, the Contractor shall provide a report to the customer/owner indicating the following:

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

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

Photographic documentation of before and after cleaning.

Work Practices199

Post Project Reporting

Work Practices200

Important:Post project reporting should be provided to the customer/owner.

If for example, cleaning was performed for an owner of a vacant buildingand a prospective tenant contacts you directly with questions of theoverall system cleanliness, you should refer the prospective tenant toconsult with the building owner.

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Before Leaving the Job…

Work Practices201

When finishing up the air duct cleaning project, check that the system functions properly in heating/cooling mode prior to leaving the client's property.

Practical Application…

To clean a duct constructed of 26‐gauge sheet metal, an

access opening 14" x 14" must be created. Which of the following sheet

metal patches should be used as a closure? (A) 16" x 16", 26 gauge (B) 16" x 16", 28 gauge (C) 15" x 15", 28 gauge (D) 14" x 14", 26 gauge

202

What gauge measures the pressure differential of the air flow across the coil?

(A) Negative Pressure gauge

(B) Magnehelic Differential Pressure gauge

(C) Positive gauge

(D) Vapor gauge

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This Concludes Module 4 Performing the Cleaning


Module 5 - HVAC Cleaning and Mold Remediation

204


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Overview: WHAT WE’LL LEARN:

Bacteria & Fungi

IICRC S520 and Other Mold Guidelines, Standards and Regulations

Assessing Biological Contamination

Microbial Remediation Overview

Managing the Workspace Environment During Microbial Remediation

Microbial Remediation & Containment

Indoor Environmental Professionals (IEP)

HVAC Cleaning and Mold Remediation205

Bacteria and Fungi

Microbiology is the study of microorganisms, which are microscopic, unicellular, and cell‐cluster organisms.

Microbiology is a broad term which includes virology, mycology, parasitology, bacteriology

Colony Forming Unit (CFU) of Mold

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Mold: A Definition

Molds, mushrooms, mildews, and yeasts are all classified as fungi, a kingdom of organisms distinct from plants and animals.

Molds are ubiquitous in nature and grow almost anywhere indoors or outdoors

StachybotrysExample of filamentous mold

Bacteria and Fungi207


Mold: A Definition

Reproduce by making spores

Travel through air

Survive a long time

The filamentous parts of mold (hyphae) form a network called mycelium

Produce volatile organic compounds (VOCs) or microbial VOCs (mVOCs)

Mycotoxins

Toxigenic molds

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Most fungi reproduce and spread through the distribution of spores

Fungal spores come from environmental sources

Fungi are ubiquitous in the environment and critically affect the welfare of all living organisms in the environment

Molds are microorganisms that utilize organic substrates as nutrient sources in the presence of moisture

Where does mold come from?


Factors That Produce Mold Growth

In addition to SPORES, mold needs the following to reproduce…..

Moisture

Nutrients

Oxygen


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Mold Growth

The primary factor limiting the growth of mold indoors is lack of moisture

Studies of mold growth on

building materials, such as

plywood, have found that

mold grows on materials that

remain wet for 48‐72 hours

Source: CDC Recommendations and Reports – 2006, Mold Prevention Strategies and

Possible Health Effects in the Aftermath of Hurricanes and Major Floods


Bacteria

Bacteria are a large domain of prokaryotic microorganisms.

Typically a few micrometers in length, bacteria have a wide range of shapes, ranging from spheres to rods to spirals


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10um

Brittlebush Pollen

SEM Image 4 ‐ 1000x

Bacteria and Fungi

5um

Brittlebush Pollen SEM Image 6 ‐ 3300x

5um

CD ImageSEM Image 2 ‐ 5000x

213

Bacteria

Are present in most habitats on Earth

There are approximately ten times as many bacterial cells in the human flora as there are human cells in the body, with large numbers of bacteria on the skin

The most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people a year, mostly in sub‐Saharan Africa


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Where Does Bacteria Come From?

Bacteria is abundant in air, water, soil, in and on animals, on plant surfaces, and on man‐made surfaces both indoors and outdoors

The indoor air of occupied buildings typically contains higher concentrations and more types of bacteria than outdoor air

In non‐manufacturing environments, the majority of bacteria in the air are shed from human skin and respiratory tracts

–American Conference of Governmental Industrial Hygienists (ACGIH Bioaerosols Assessment and Control)


Where Does Bacteria Come From?

Bacteria are everywhere

Areas of HVAC systems that are moist or wet are great areas for bacteria to reproduce

Use caution when working around or cleaning wet materials or wet areas such as drain pans or cooling towers

Remember bacteria are too small to see with the human eye


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IICRC S520

The purpose of the IICRC S520 Standard is to provide requirements for mold remediation techniques.


IICRC S520 – Indicators of microbial growth

“In addition to visible mold growth and the detection of moisture in porous materials, an obvious indicator of microbial amplification is an odor that may be described as musty, moldy or mildewy. Fungi and bacteria produce a variety of volatile organic compounds (VOCs) during active growth.”


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OSHA, “A Brief Guide to Mold in the Workplace”

If you suspect that the HVAC system is contaminated with mold, or if mold is present near the intake to the system, contact the National Air Duct Cleaners Association (NADCA), or consult EPA's guide, "Should You Have the Air Ducts in Your Home Cleaned?" before taking further action.

Do not run the HVAC system if you know or suspect that it is contaminated with mold, as it could spread contamination throughout the building.


ACR, The NADCA Standard ‐Cleaning & Restoration Procedures

Remediation of Mold and Other Biological Contamination:

The remediation plan for mold decontamination should include removal of contaminated materials or employment of aggressive cleaning techniques when removal is impractical.

Mold contaminated, porous HVAC system materials should be properly removed and replaced. (See ACGIH Bioaerosols: Assessment and Control).

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ACR, The NADCA Standard ‐Cleaning & Restoration Procedures

Removal and Disposal of Contaminated Materials:

All contaminated materials removed from the HVAC system should be properly contained to prevent cross contamination and shall be disposed of in accordance with any applicable local, state, regional or federal regulations.

NADCA Standard ACR ‐Mold 221

Surface Treatments:

Surface treatments may be used to restore the integrity of material surfaces as an alternative to replacement.

Surface treatments should only be applied after confirming the system has been cleaned, and has passed the specified level of cleanliness verification.

ACR, The NADCA Standard ‐Mold

ACR, The NADCA Standard ‐ Cleaning & Restoration Procedures

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IICRC S520 & Other Mold Guidelines, Standards & Regulations

13 HVAC Remediation

13.1 HVAC Operational, Maintenance and Modification Issues

13.2 HVAC Engineering Considerations

References ACR for doing an assessment of the system.

13.3 HVAC System Cleaning and ACR

Cleaning should be carried out in accordance with the NADCA Standard ACR

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IICRC S520

IICRC S520 & Other Mold Guidelines, Standards & Regulations

13.2 HVAC Engineering Considerations

“In addition to a cleanliness inspection, a complete engineering assessment of the design and working condition of the entire HVAC system should be considered, depending on the Conditions (1,2 or 3) that exist in the project.”

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IICRC S520

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13.3.1 Use of a Mechanical System as a Dehumidification Device

When systems are used for humidity control they should be cleaned following the NADCA Standard ACR

13.3.2 Fungal Contamination Considerations References the cleanliness criteria in NADCA Standard ACR, HVAC

should be isolated from areas where structural remediation is taking place.

Discusses antimicrobial use and sealants, coatings, etc.


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IICRC S520

IICRC S520 recommends taking relative humidity readings during a project to document environmental conditions within a remediated space. A hygrometer is a device used for this purpose.

According to IICRC S520, flex duct, duct board, and internally lined ductwork with Condition 3 contamination cannot be successfully cleaned.


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IICRC S520

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Standard and Reference Guide for Professional Water Damage Restoration (2015)


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IICRC S500

During a water damage restoration, IICRC S500 states HVAC systems should not be used for dehumidification.

EPA Mold Remediation in

Schools and Commercial

Buildings – 2001


http://www.epa.gov/mold/pdfs/moldremediation.pdf

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NYC Department of Health Bureau of Environmental & Occupational Disease Epidemiology

“Guidelines on Assessment and Remediation of Fungi in Indoor Environments” – Original 1993, Revision 2000, Revision 2008

http://www.lchd.org/environhealth/aq/pdfs/NYC%20DOH%20Guidelines.pdf


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2008 Florida Statutes, Chapter 468, Part XVI,http://www.myfloridalicense.com/dbpr/pro/mold/statutes.html


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Louisiana License, Act 800, Regular Session 2003,http://www.lslbc.louisiana.gov/pdf_files/Mold%20Act.pdf

Louisiana House Bill 1328, Act 880, 2003 Regular Legislative Session (R.S 37:2181—37:2192)

MOLD; What You Need to Know About Your

Health and Property


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Contamination

The presence of undesired substances; the identity, location, and quantity of which are not reflective of a normal indoor environment and may produce adverse health effects, cause damage to structure and contents and/or adversely affect the operation or function of building systems. IICRC S‐500

Assessing Biological Contamination232

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Sick Building Syndrome

Sick Building Syndrome (SBS) is used to describe a situation in which the occupants of a building experience acute health‐ or comfort‐related effects that seem to be linked directly to the time spent in the building. No specific illness or cause can be identified.

Common symptoms of Sick Building Syndrome (SBS) may include eye, nose, and throat irritation.


Building Related Illness

The term Building Related Illness (BRI) refers to medically recognized diseases or disorders.

An HVAC system can cause Building Related Illness (BRI) if germs in the system infect building occupants.


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Condition 1

normal fungal ecology

Condition 2

settled spores

Condition 3

actual growth


Mold will not grow without moisture and a food source

Mold colonies will typically grow in circular patterns

Mold growth can vary in color

Mold and bacteria have a musty, mildew or earthy odor when they are growing on materials

Samples of materials must be analyzed by a laboratory to confirm the presence of mold


Five Key Concepts of Assessment for Mold Contamination

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Some of the common tools used to investigate for mold are also used to assess HVAC systems


Investigation for mold contamination is typically done by Indoor Environmental Professionals (IEP)s or properly trained supervisors.

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According to IICRC S520 ‐

During an HVAC cleaning project, if asked to identify suspect microbial contamination, it’s best to recommend that a qualified Indoor Environmental Professional (IEP) collect samples for lab analysis.

Where Mold Contamination is commonly found in HVAC Systems

Assist your supervisor in determining if previously undiscovered mold has been found during cleaning

Recognize when additional safety and PPE precautions are advisable

mold contaminationtypical dust and dirt build up


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Areas of an HVAC system where moisture may be present and tend to accumulate the most dirt and dust.


Commercial Humidifier Residential Humidifier


Areas of an HVAC system that tend to accumulate the most dirt and dust

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Microbial Remediation Overview (Structural Remediation)

What is Mold remediation?

According to all Federal, State and Local Regulations, industry standards or guidelines, mold remediation is fixing the moisture problem and the physical removal of all growth.

The Federal government does not

have regulations covering fungal

contamination of the indoor

environment.

Microbial Remediation Overview241

Important Definitions

Actual growth

molds that have colonized a substrate, formed fungal mycelia, growth structures, and spores; are active or dormant, visible or hidden

Containment

the act or condition of containing (Websters)

Containment

a precaution used to minimize cross‐contamination from an affected area to unaffected areas by traffic or material handling (IICRC S520)

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Administrative Controls

Occupational Safety and Health Administration (OSHA)

Processes and activities utilized before and at the start of a project

Ensure the health and safety of occupants and workers

Examples

Job specific emergency procedures

Training

Scheduling

Moving people to other areas, etc


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Administrative ControlsExamples


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Used to ensure worker/technician safety and health

Help prevent cross‐contamination

Engineering Controls/Work Practices


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According to the IICRC S520, engineering controls include but are not limited to:

Contamination source control

HEPA vacuuming and filtration

Isolation barriers

Detailed cleaning

Pressure differentials

Temperature and humidity control

Dust suppression methods

A sanitary approach

Engineering Controls/Work Practices


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Personal Protective Equipment (PPE)

Your supervisor will determine what level of personal protective equipment is necessary

Use the selected equipment and maintain PPE

Remember PPE is the last line of defense; you should continue to use appropriate engineering controls and work practices to lower exposure first, and then supplement with appropriate PPE.


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According to the New York City New York City Department of Health and Mental Hygiene Guidelines On Assessment and Remediation of Fungi in Indoor Environments, adverse health effects of mold due to inhalational exposure may include:

Allergic reactionsToxic effects and irritation Infections

“The mere presence of mold growth does not necessarily indicate that people present in the area will exhibit adverse health effects. However, as the amount of mold‐impacted materials increases, so do potential exposures. Certain exposures may represent a significant risk such as occupational exposures to high concentrations of fungi and chronic (long‐term) exposures, especially of individuals with underlying health conditions such as asthma, compromised immune systems, or allergies.”


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Microbial Remediation & Containment249

Verification of Completion

Every project can have different requirements for verification of completion.

Be prepared to make recommendations for how to achieve the expected results and remember that communication with your supervisor is the key to a successful project


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Verification of Completion


All communications with clients and others should only be made through your company’s designated contact.

If hidden mold is discovered talk to your supervisor!

A written change order may be necessary.

Supervisor may perform a post remediation evaluation to determine if scope of work is complete.

Post Remediation Verification (PRV) by an independent third party if applicable.

Types of Containment

Why use containment structures? – Contamination is best controlled at the source and containment is the best way of controlling contamination


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Types of Containment

The American Conference of Governmental Industrial Hygienists (ACGIH) book “Bioaerosols Assessment and Control” describes three levels of containment for microbial remediation projects

Source Containment

Local Containment

Full‐Scale Containment


Source Containment

Source control with HEPA Vacuum


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Source Containment

Vacuum collection equipment that should be used on almost every HVAC cleaning project is a type of source containment.


Full Scale Containment

A HEPA equipped Air Filtration Device (AFD), a.k.a. negative air unit, is used to keep the work area under negative pressure with respect to the non‐contaminated outside area.


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Containment Construction Basics

Containment begins with sealing off all penetrations to the work area.

A properly designed containment will stop the spread of contamination and limit the scope of work.

Airflow should be away from clean areas and toward the negative air source.


Air Exchange

The HVAC industry standard is 4 or more air changes per hour. The mold industry has adopted the asbestos industry requirement of 4‐12 air changes per hour.

This standard has been adopted by much of the mold remediation industry IICRC Air Exchange Formula


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Example – How Many Air Exchanges Will Occur in One Hour?

A room is 15 feet long, 20 feet wide, and 8 feet high

L X W X H = Total Area (cubic feet)

15 X 20 X 8 = 2,400 cubic feet

An negative air machine is delivering 1200 CFM

1200 CFM X 60 minutes = 72,000 cubic feet per hour

72,000 divided by 2400 = 30 air changes/hour


CFM = Space Cubic Feet X 4 Air Exchanges/Hr

60

2400 X 4

60=160 CFM

Example – You Need 4 Air Changes per Hour


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Understanding Air Exchange

Various instruments are available which monitor the pressure drop continuously.

According to IICRC S520, negative pressure microbial remediation containments should provide a minimum of 4 air changes per hour and ‐0.02 inches of water column/gauge,which is approximately equal to 5 pascals


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Checking Negative PressureACR, The NADCA Standard Engineering Controls for HVAC Cleaning and Restoration ProjectsNegative Pressure Requirements: A continuous negative pressure should be maintained in the portion of the HVAC system being cleaned in relation to the surrounding indoor spaces. It is recommended that the negative pressure be verified at representative locations during the cleaning process.


Pressure Monitor


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HVAC Cleaning and Mold Remediation Q & A

Q: Should HVAC cleaning or mold remediation be done first?

A: Most often HVAC cleaning is completed after mold remediation is completed. During the structural remediation, the HVAC system should be sealed off from the mold remediation areas.

Generally speaking HVAC cleaning should not be done during mold remediation. It is preferable to have the HVAC cleaning done after the other portions of the project are done.



Q: How much mold in an HVAC system is OK to just clean as part of HVAC cleaning?

A: There is no specific guidance on this issue. Some documents, ie. New York City Guidelines, consider less than 10 square feet of mold contamination to be a small project that does not require extraordinary precautions. However, less than 10 square feet in an air handling unit serving a neonatal intensive care unit would require extreme caution.


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Q: How much mold in an HVAC system is OK to just clean as part of HVAC cleaning?

A: HVAC cleaning when done properly is done under containment with vacuum collections devices but even the ACR states this may not be enough for certain types of mold remediation projects.


Containment Frames Assembled


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Level 1‐ HVAC Containment

ACR Level 1 Containment: Level 1 is the minimum level of containment that should be used on all HVAC system cleaning projects.

Negative Pressure

Protective Coverings

Cleaning Equipment and Tools

Cross Contamination Control


ACR, The NADCA Standard ‐ Protective Coverings


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Cross Contamination Control

Example ‐ Fan sealed for cleaning unit exterior with HEPA Vacuum.

This may require temporary sealing of duct joints, seams and system components


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

that should be used on all HVAC system cleaning projects.

Protective Coverings: Clean, protective coverings should be used within the work area. Protective coverings should extend beyond the work area to provide protection of flooring, equipment, and furniture whenever necessary.

Cleaning Equipment and Tools: All tools and equipment should be maintained as described in the ACR.

Cross Contamination Control: Engineering controls should be in place

to control contaminant discharge from the HVAC system and/or cross

contamination into occupied space during the cleaning process.


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Level 2 Containment

Level 2 Containments (Temporary Barriers)

All level 1 containment requirements apply to Level 2 Containments.

Temporary barriers should be constructed.

It is recommended that containment barriers are erected from floor to ceiling when applicable.

It is recommended that above ceiling work areas are isolated from occupied spaces and/or non work areas when applicable.

Its recommended that containment barriers are built utilizing 6‐mil fire retardant polyethylene sheeting or equivalent.

These barriers are recommended to be sealed airtight where they meet the ceiling, floor, and walls or other areas.


Entrance to Containment with two flaps


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Demonstrating Entrance Flaps


Dismantling

Interior surfaces of the containment enclosure should be wet‐wiped and/or HEPA vacuumed before moving or dismantling the containment enclosure.

In the healthcare environment, an appropriate post‐remediation verification should be performed prior to dismantling the containment.


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Level 3 Containment

Level 3 Containment: Level 3 is a containment with a single chamber decontamination unit.

Include Level 1 and Level 2 Requirements: All of the Level 1 and 2 Containment requirements apply to Level 3 Containments.

Decontamination Facility: A single chamber decontamination facility should be utilized in conjunction with the containment area. The decontamination chamber should be attached and sealed directly to the containment area.

Monitoring Requirements: Level 3 Containment areas should be monitored for negative pressure on a continuous basis by using an instrument sensitive enough to detect a loss of negative pressure.


Laser Particle Counter to Monitor Containment


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Level 4 Containment

Level 4 Containment: A Level 4 Containment is a containment with a Two Chamber Decontamination Unit.

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.

Decontamination Facility: A decontamination facility as described for a Level 3 Containment area should be utilized, except that the decontamination facility should consist of two chambers. Each chamber should be constructed according to the requirements described for a Level 3 Containment area.

Monitoring Requirements: Monitoring requirements described for a Level 3 Containment area apply.


ACR, The NADCA Standard ‐ 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 should be considered a priority on every project.

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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Equipment Redundancy ‐ The redundant equipment is specified as either concurrent operation or non‐concurrent operation.

Concurrent‐ Back up equipment (for redundancy) is on at the same time as the primary equipment.

When concurrent operation is required, the loss of either piece of equipment should not affect the containment, engineering controls or safety.


The use of Indoor Environmental Professionals or (IEP) is common on large commercial mold remediation projects and on some residential projects.

The IICRC S520 recommends the use of an independent IEP on projects where the scope of work is not clear or when there have been complaints about health related issues that may be caused by the mold in a home or building.

IEP is a generic term that describes someone with education, training and experience of performing assessments of indoor environments.

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Do you know?

Which of the following components is MOST likely to contain microbial growth?

(A) Blower wheel housing

(B) Condensate drain line and pan

(C) Interior side walls of HVAC unit

(D) Turning vanes

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This Concludes Module 5 HVAC Cleaning and Mold

Remediation

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Acknowledgements

We would like to acknowledge the following individuals for their contribution in developing this publication:

NADCA Education Committee (2016)

Copyright © 2016 NADCA, All Rights Reserved

No part of this publication may be reproduced or distributed by any means, electronic or mechanical, including photocopy, recording, or any other information storage and retrieval system, without prior written consent from the publisher.

THANK YOU FOR PARTICIPATING


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