Basics of HVAC Cleaning
Seminar Outline Residential 1. Types of systems used and why 2. Types of air distribution systems 3. System components 4. Determining the need for cleaning (ACR2002) 5. Project assessment (ACR2002) 6. Cleaning procedures 7. Filtration
Seminar Outline Commercial 1. Typical HVAC systems 2. HVAC system components 3. Performing a HVAC system inspection and report 4. Understanding mechanical drawing symbols 5. HVAC cleaning procedures/methods 6. The challenges of fiberglass insulation
Housekeeping Restroom Lunch Questions Cell phones/pagers
Disclaimer The information in this outline is furnished for information purposes only and is subject to change without notice. Every effort has been made to provide reliable information and guidance. NADCA assumes no responsibilities or liability for any errors or inaccuracies that may appear in this presentation.
Disclaimer The methods and techniques for cleaning and project managing ventilation cleaning projects outlined may not be applicable to every ventilation system and cleaning project. Ventilation cleaning technicians must be competent, careful and use common sense. Licensing and certification of technicians may be required, check your state s requirements.
Mechanical Hygiene Indoor Air Quality (IAQ) HVAC Systems
Indoor Air Quality (IAQ) is one of the most important environmental issues facing us today!
The World Health Organization (WHO) has stated that 30% of all buildings can be categorized as having sick building syndrome (SBS) Ref: World Health Organization
Studies indicate that indoor air levels of pollutants may be 2-5 times, and occasionally 100 times, higher than outdoor levels. Ref: Environmental Protection Agency
Health care costs attributable to poor IAQ are in the neighborhood of $15 billion per year. Ref: American Medical Association
Productivity losses due to poor IAQ could reach 18% Ref: American Management Association
85% of Americans don t know the air in their homes may be hazardous to their health. The quality of indoor air is something all Americans should be concerned about. Ref: American Lung Association
NIOSH Study shows 53% of IAQ problems were caused by problems with or in the ventilation system. * Ventilation systems are prime suspects Ref: EPA
Dirty Sheet metal
Dirty Lined duct
Dirty Turning Vanes
Dirty Exhaust
Dirty Fan
Microbial Contamination
Types of Residential System fuel Gas Oil Electric Coal Wood
Types of furnaces/air conditioners Up flow Down flow Horizontal
Upflow Furnace
Forced Air With A/C
Forced Air With A/C Up Flow Hi Efficiency
Horizontal System
Oil Burner
System Components Blowers/Fans Direct drive Belt drive Coils and drain pans Ducts Combustion Side
Residential blowers and motors Belt Drive Direct Drive
Typical indoor cooling coil
Typical outdoor condensing unit
Types of distribution systems Attic Basement in floor Basement overhead Crawl space
Upflow Duct System
Down Flow Duct System
Horizontal Unit Duct System
Return Panned Joist Duct
Ducts in attic
Insulated Flex Duct Access only from ends Designed for short runs
Sheet Metal Duct With Insulation NADCA Standard for cutting & patching Microbial issues Reasons for insulation in duct Coatings
Duct Board NADCA standard for cutting and patching. Microbial issues Reasons for using this type Coatings
Externally insulated duct NADCA Standard for cutting & patching Reasons for insulation
Cleaning Procedures Combustion side Air distribution side
Post Cleaning Treatments Sanitizing Coating EPA
NADCA Customer Informed Consent Form
Filtration Electronic (mechanical) Electrostatic (non mechanical) 4 pleated extended surfaces 2 pleated 1 pleated Fiberglass/poly media
Concerns with higher efficiency filter? Section 7.3 Restriction Of Air Flow
Are you using HEPA filters on all your indoor vacs?
Q & A - Residential
Commercial
2. Typical HVAC Systems A. Constant Volume Systems: fan coil systems water source heat pump systems packaged terminal systems B. Variable Air Volume Systems: with radiation heat with reheat systems two fan dual duct fan powered
c. High, Medium & Low Pressure Systems: Pressure Velocity Classification The use of the term "low" and "high" as applied to velocity and/or pressure is arbitrary, and it has been discontinued. The designer must select a numerical static pressure class or classes which specify the requirements of the of the particular system. Pressure Class Operating Pressure.5 w.g. Up to.5 w.g. 1 w.g. Over.5 up to 1 w.g. 2 w.g. Over 1 up to 2 w.g. 3 w.g. Over 2 up to 3 w.g. 4 w.g. Over 3 up to 4 w.g. 6 w.g. Over 4 up to 6 w.g. 10 w.g. Over 6 up to 10 w.g.
Takes minimal amount of equipment to clean. Once you get cabinet panels off, there is good accessibility. Older ones can be difficult to disassemble and reassemble.
Ceiling space makes it difficult to work on. Poor access to supply fans. Shaft drive motors do not allow for easy pressure washing with out water damage to motor. Normally insulated No return duct Have condensate pan and drain, but additional water control is necessary.
Takes minimal amount of equipment to clean. Once you get cabinet panels off, there is good accessibility. Older ones can be difficult to disassemble and reassemble.
Spiral duct from AHU to VAV. Accessibility to clean VAV boxes. Use slot diffusers or troffers which creates a higher level of difficulty for cleaning or coating.
Spiral duct from AHU to VAV. Accessibility to clean VAV boxes plus clean fan & coil. Use slot diffusers or troffers which creates a higher level of difficulty for cleaning or coating.
Spiral duct from AHU to VAV. Accessibility to clean VAV boxes and coil. Use slot diffusers or troffers which creates a higher level of difficulty for cleaning or coating.
Spiral duct from AHU to VAV. Twice as much supply duct from AHU to VAV s
Spiral duct from AHU to VAV. Twice as much supply duct from AHU to VAV s
Accessibility to clean VAV boxes and coil. Use slot diffusers or troffers which creates a higher level of difficulty for cleaning or coating.
Determine accessibility Water Control Location of water and electrical Fiberglass insulation
Determine accessibility Water Control Fiberglass insulation Location of water and electrical
Heat Pump No return ducts Determine accessibility Water control Fiberglass insulation
Good Access Water control Fiberglass insulation
Accessibility Water control Fiberglass insulation
Fiberglass insulation Pneumatic control
Normally in supply Plenum Locate shut off valves for lock/out Cleaning/maintenance not in scope of work Can be source of moisture for microbial growth
Can be source of microbial growth Hardware to be rusty
Reheat Coil Need access on both sides No condensate drain Need to set up water control
F. Automation components/sensors: - humidistat - smoke detector - low temperature stat - freeze stat - pressure sensor -etc Consider removal to eliminate damage Have certified after cleaning
Slot Diffusers Not easily removed Rubber bladder Air wash
Diffuser Boxes Designed to direct air flow Fiberglass insulation Not easily accessed
Fire Rated Diffuser Found in kitchens or labs Caution not to break or disconnect fusible links
Rooftop Ducting Supply on perimeter Return in center
Sound Baffle Fiberglass insulation Perforated metal Microbial issues Cannot properly clean Coating?
Sound Baffles Redirects airflow
Sound Baffle Fiberglass insulation Perforated metal Microbial issues Cannot properly clean Coating?
Insulated Flex Duct Access only from ends Designed for short runs
Sheet Metal Duct with internal insulation NADCA Standard for cutting & patching Microbial issues Reasons for insulation in duct Coatings
Externally insulated duct NADCA Standard for cutting & patching Reasons for insulation
Duct Board NADCA standard for cutting and patching. Microbial issues Reasons for using this type Coatings
Harder to access Don t cut into butt joints Mostly used in exhaust systems
Harder to access
Electrical Duct Heater Can damage easily Air wash only Lock out issues
Very specific application May need to remove to clean duct
Cutting and patching NADCA 05 1997 Requirements for the Installation of Service Openings in HVAC Systems
Performing a HVAC System Inspection & Report a. HVAC survey checklist b. HVAC survey report c. Photographic report d. Video report
HVAC Mechanical Hygiene Survey
HVAC Mechanical Hygiene Survey
Robotic System
Visual Inspection System
Understanding Mechanical Drawings (Symbols) Centrifugal
Understanding Mechanical Drawings (Symbols) Roof Ventilator, Intake Roof Ventilator, Exhaust
Understanding Mechanical Drawings (Symbols) Direction of Flow Duct Size
Understanding Mechanical Drawings (Symbols) Duct Section, Positive Pressure Duct Section, Negative Pressure
Understanding Mechanical Drawings (Symbols) Change of Elevation
Understanding Mechanical Drawings (Symbols) Access Doors, Vertical or Horizontal Acoustical Lining (insulation)
Understanding Mechanical Drawings (Symbols) Flexible Duct Sound Attenuator
Understanding Mechanical Drawings (Symbols) Terminal Unit, Mixing Terminal Unit, Reheat
Understanding Mechanical Drawings (Symbols) Transition Turning Vanes
Understanding Mechanical Drawings (Symbols) Detectors, Fire & or Smoke
Understanding Mechanical Drawings (Symbols) Fire Damper & Sleeve, Vertical Position Fire Damper & Sleeve, Horizontal Position
Understanding Mechanical Drawings (Symbols) Manual Volume Manual Splitter
Understanding Mechanical Drawings (Symbols) Smoke Damper
Understanding Mechanical Drawings (Symbols) Exhaust Grille or Register Supply Grille or Register
Understanding Mechanical Drawings (Symbols) Grille or Register, Ceiling Ceiling Diffuser, Rectangular
Understanding Mechanical Drawings (Symbols) Ceiling Diffuser, Round Diffuser, Linear
Understanding Mechanical Drawings (Symbols) Diffuser & Light Fixture Combination Transfer Grille Assembly
a. Preparation of work site 1. The time work can be done without disrupting normal working operations of the building and its occupants. 2. Select all equipment and materials needed. 3. Select methods of cleaning: a. Air washing method b. Power brushing method c. Contact vacuum method e. Electrical hookups and water spigots. 4. Precautions when shutting down HVAC systems: a. Steam valves b. Mark damper positions c. Coil freeze-up precautions d. Shut down communications with client
Partial shutdown and zoning duct system Cross contamination System Balancing Critical barriers
Reheat Coil Need access on both sides No condensate drain Need to set up water control
Accessibility Water control Fiberglass insulation
Fiberglass insulation Pneumatic control
Process for removing fiberglass insulation Dry removal Wet removal
The Challenge of Cleaning and Coating Fiberglass Insulation
The Challenge of Cleaning and Coating Fiberglass Insulation #1 Rule If you can t clean it, you can t coat it!
Cleaning Guidelines As you conduct your inspection, ask yourself the following four questions. If all of our answers are yes, then you can proceed with your cleaning. If any of your answers are no, you should remove or replace the fiber glass duct liner or fiber glass duct board. 1. Is the duct liner properly secured to the interior of the sheet metal duct or air handling unit? 2. Is the duct board properly installed? 3. Does the duct liner or duct board still have it s acoustical value? 4. Is the duct liner or duct board in a dry condition?
Coating Guidelines 1. Remove a sample section of fiber glass duct liner or fiber glass duct board. This section should be between 12 x 12 to 18 x 18. 2. Clean this section using your normal cleaning procedures. (You may want to clean the sample section in place first and then remove it, if that is easier). 3. Apply the coating to the air stream surface of the sample section using the same procedure you would normally use. We recommend using an airless sprayer capable of 2500 psi at.5 gpm or a robotics system. Tip size may vary based on the products used. 4. Let the sample dry, evaluate with your client, and make any necessary adjustments.