By: Indoor Air Quality  11-11-2011
Keywords: Air Quality, Indoor Air Quality, Duct Cleaning

We have developed a distinctive approach to evaluating buildings for Air Quality, including molds and bacteria.

Sick Building syndrome and building disease are more likely in large commercial spaces because of the complexity of the HVAC systems.

As buildings age the potential for isolated problems increase, while the possibility of building wide decreases The question now is; what is the condition of my facility's HVAC System? Without a detailed inspection it is virtually impossible to know what potential problems you might be dealing with. The next question is; who can I find to provide an inspection?

The answer is Autumn Star Duct Cleaning & Decontamination

Your HVAC System will include a detailed report that will include:
• Findings from the inspection
• Recommendations based on our findings, in regards to such areas as the need for HVAC Systems
cleaning, the need for Indoor Air Quality (IAQ) testing, repair of internally lined insulation, etc.
• All reports will be prepared by an experienced Air Duct Cleaning Specialist.

Indoor Air Quality - Duct Cleaning - Pretoria Gauteng South Africa

Phase I – The Initial Survey
Investigation of the Indoor Environment
Preliminary information gathering, obtain information on the building
Complains of any illnesses (if any)
Inspection of HVAC system
Testing of Indoor parameters such as temperature, relative humidity and volatile organic compounds
Written report of founding's and recommendations

Phase II – In Depth investigation
Where situation cannot be resolved by Phase I evaluation , and extend of the problem are greater than anticipated, or more testing and evaluation is necessary; the Phase II investigation would be performed;
More extensive examination of the HVAC system
Continuous monitoring of basic Air Quality
Testing and analysis of airborne bacteria/fungi
Microscopic analysis

Phase III - Remediation
Once problems have been identified, we can participate in corrective measures
Specifications and plans for remediation
Bacterial decontamination
Oversight and project management of abatement or remediation
Final air sampling, mold or bacteria sampling, chemical analysis to ensure cleaning is complete

Indoor Air Quality - Duct Cleaning - Pretoria Gauteng South Africa

HVAC System Component Inspections and Site Preparations Cleaning Requirements

A) HVAC System Component Inspections:

Prior to the commencement of any cleaning work, the HVAC system cleaning contractor shall perform a visual inspection of the HVAC system to determine appropriate methods, tools, and equipment required to satisfactorily complete this project. The cleanliness inspection should include air handling units and representative areas of the HVAC system components and ductwork. In HVAC
systems that include multiple air handling units, a representative sample of the units should be inspected. The cleanliness inspection shall be conducted without negatively impacting the indoor environment through excessive disruption of settled dust, microbial amplification or other debris. In cases where contamination is suspected, and/or in sensitive environments where even small amounts of contaminant may be of concern, environmental engineering control measures should be implemented

B) Site Evaluation and Preparations:

Contractor shall conduct a site evaluation, and establish a specific, coordinated plan which details how each area of the building will be protected during the various phases of the project.

C) Inspector Qualifications:
Qualified personnel should perform the HVAC cleanliness inspection to determine the need for cleaning. At minimum, such personnel should have an understanding of HVAC system design, and experience in utilizing accepted indoor environmental sampling practices, current industry HVAC cleaning procedures, and applicable industry standards.

Indoor Air Quality - Duct Cleaning - Pretoria Gauteng South Africa

General HVAC System Cleaning Requirements

A) Containment:

Debris removed during cleaning shall be collected and precautions must be taken to ensure that Debris is not otherwise dispersed outside the HVAC system during the cleaning process.

B) Particulate Collection:

Where the Particulate Collection Equipment is exhausting inside the building, HEPA filtration with 99.97% collection efficiency for 0.3-micron size (or greater) particles shall be used. When the Particulate Collection Equipment is exhausting outside the building, Mechanical Cleaning operations shall be undertaken only with Particulate Collection Equipment in place, including adequate filtration to contain Debris removed from the HVAC system. When the Particulate Collection Equipment is exhausting outside the building, precautions shall be taken to locate the equipment down wind and away from all air intakes and other points of entry into the building.

(C) Controlling Odors:

Measures shall be employed to control odors and/or mist vapors during the cleaning process.

D) Component Cleaning:

Cleaning methods shall be employed such that all HVAC system components must be Visibly Clean as defined in applicable standards (see NADCA Standards). Upon completion, all components must be returned to those settings recorded just prior to cleaning operations.

E) Air-Volume Control Devices:

Dampers and any air-directional mechanical devices inside the HVAC system must have their position marked prior to cleaning and, upon completion, must be restored to their marked position.

F) Service Openings:

The contractor shall utilize service openings, as required for proper cleaning, at various points of the HVAC system for physical and mechanical entry, and inspection.

1. Contractor shall utilize the existing service openings already installed in the HVAC system where possible.
2. Other openings shall be created where needed and they must be created so they can be sealed in accordance with industry codes and standards.
3. Closures must not significantly hinder, restrict, or alter the airflow within the system.
4. Closures must be properly insulated to prevent heat loss/gain or condensation on surfaces within the system.
5. Openings must not compromise the structural integrity of the system.
6. Construction techniques used in the creation of openings should conform to requirements of applicable building and fire codes, and applicable NFPA, SMACNA and NADCA Standards.
7. Cutting service openings into flexible duct is not permitted. Flexible duct shall be disconnected at the ends as needed for proper cleaning and inspection.
8. Rigid fiber glass duct systems shall be resealed in accordance with NAIMA recommended practices. Only closure techniques that comply with UL Standard 181 or UL Standard 181a are suitable for fiber glass duct system closures.
9. All service openings capable of being re-opened for future inspection or remediation shall be clearly marked and shall have their location reported to the owner in project report documents.

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

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

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

1. Clean all air handling units (AHU) internal surfaces, components and condensate collectors and drains.
2. Assure that a suitable operative drainage system is in place prior to beginning wash down procedures.
3. Clean all coils and related components, including evaporator fins.

J) Duct Systems. Contractor shall:

1. Create service openings in the system as necessary in order to accommodate cleaning of otherwise inaccessible areas.
2. Mechanically clean all duct systems to remove all visible contaminants, such that the systems are capable of passing Cleaning Verification Tests (see NADCA Standards).

Indoor Air Quality - Duct Cleaning - Pretoria Gauteng South Africa

Health and Safety

A) Safety Standards:

Cleaning contractors shall comply with applicable federal, state, and local requirements for protecting the safety of the contractor’s employees, building occupants, and the environment. In particular, all applicable standards of the Occupational Safety and Health Administration (OSHA) shall be followed when working in accordance with this specification.

B) Occupant Safety:

No processes or materials shall be employed in such a manner that they will introduce additional hazards into occupied spaces.

C) Disposal of Debris:

All Debris removed from the HVAC System shall be disposed of in accordance with applicable federal, state and local requirements.

Indoor Air Quality - Duct Cleaning - Pretoria Gauteng South Africa

Mechanical Cleaning Methodology

A) Source Removal Cleaning Methods:

The HVAC system shall be cleaned using Source Removal mechanical cleaning methods designed to extract contaminants from within the HVAC system and safely remove contaminants from the facility. It is the contractor’s responsibility to select Source Removal methods that will render the HVAC system Visibly Clean and capable of passing cleaning verification methods (See applicable NADCA
Standards) and other specified tests, in accordance with all general requirements. No cleaning method, or combination of methods, shall be used which could potentially damage components of the HVAC system or negatively alter the integrity of the system.

1. All methods used shall incorporate the use of vacuum collection devices that are operated continuously during cleaning. A vacuum device shall be connected to the downstream end of the section being cleaned through a predetermined opening. The vacuum collection device must be of sufficient power to render all areas being cleaned under negative pressure, such that containment of debris and the protection of the indoor environment are assured.
2. All vacuum devices exhausting air inside the building shall be equipped with HEPA filters (minimum efficiency), including hand-held vacuums and wet-vacuums.
3. All vacuum devices exhausting air outside the facility shall be equipped with Particulate Collection including adequate filtration to contain Debris removed from the HVAC system. Such devices shall exhaust in a manner that will not allow contaminants to re-enter the facility. Release of debris outdoors must not violate any outdoor environmental standards, codes or regulations.
4. All methods require mechanical agitation devices to dislodge debris adhered to interior HVAC system surfaces, such that debris may be safely conveyed to vacuum collection devices. Acceptable methods will include those, which will not potentially damage the integrity of the ductwork, nor damage porous surface materials such as liners inside the ductwork or system components.

B) Methods of Cleaning Fibrous Glass Insulated Components

1.Fibrous glass thermal or acoustical insulation elements present in any equipment or ductwork shall be thoroughly cleaned with HEPA vacuuming equipment, while the HVAC system is under constant negative pressure, and not permitted to get wet in accordance with applicable NADCA and NAIMA
standards and recommendations.

2. Cleaning methods used shall not cause damage to fibrous glass components and will render the system capable of passing Cleaning Verification Tests (see NADCA Standards).

C) Damaged Fibrous Glass Material

1. Evidence of damage: If there is any evidence of damage, deterioration, delaminating, friable material, mold or fungus growth, or moisture such that fibrous glass materials cannot be restored by cleaning or resurfacing with an acceptable insulation repair coating, they shall be identified for replacement.

2.Replacement: When requested or specified, Contractor must be capable of remediating exposed damaged insulation in air handlers and/or ductwork requiring replacement.

3.Replacement material: In the event fiber glass materials must be replaced, all materials shall conform to applicable industry codes and standards, including those of UL and SMACNA. Replacement of damaged insulation is not covered by this specification.

D) Cleaning of coils

Any cleaning method may be used which will render the Coil Visibly Clean and capable of passing Coil Cleaning Verification (see applicable NADCA Standards). Coil drain pans shall be subject to Non-Porous Surfaces Cleaning Verification. The drain for the condensate drain pan shall be operational. Cleaning methods shall not cause any appreciable damage to, displacement of, inhibit heat transfer, or erosion of the coil surface or fins, and shall conform to coil manufacturer recommendations when available. Coils shall be thoroughly rinsed with clean water to remove any latent residues.

E) Antimicrobial Agents and Coatings

1. 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.

2. 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.

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

4. 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.

Indoor Air Quality - Duct Cleaning - Pretoria Gauteng South Africa

Cleanliness Verification

A) General:
Verification of HVAC System cleanliness will be determined after mechanical cleaning and before the application of any treatment or introduction of any treatment-related substance to the HVAC system, including biocidal agents and coatings.

B) Visual Inspection:
The HVAC system shall be inspected visually to ensure that no visible contaminants are present.

1.If no contaminants are evident through visual inspection, the HVAC system shall be considered clean; however, the owner reserves the right to further verify system cleanliness through Surface Comparison Testing or the NADCA vacuum test specified in the NADCA standards.

2.If visible contaminants are evident through visual inspection, those portions of the system where contaminants are visible shall be re-cleaned and subjected to re-inspection for cleanliness.

3.NADCA vacuum test analysis should be performed by a qualified third party experienced in testing of this nature.

C) Verification of Coil Cleaning
Cleaning must restore the coil pressure drop to within 10 percent of the pressure drop measured when the coil was first installed. If the original pressure drop is not known, the coil will be considered clean only if the coil is free of foreign matter and chemical residue, based on a thorough visual inspection (see NADCA Standards).

Indoor Air Quality - Duct Cleaning - Pretoria Gauteng South Africa

Keywords: Air Duct Cleaning, Air Quality, Building Syndrome, Duct Cleaning, Indoor Air Quality

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