evaluation of steam cleaning in ahu coil …...2019 iaqa annual meeting frank santini, jd, mba pure...
TRANSCRIPT
2019 IAQA Annual Meeting
Frank Santini, JD, MBA
Pure Air Controls Services, Inc.
Office: 727-572-4550 ext. 804
Cell: 727-515-2960
Evaluation of Steam Cleaning in
AHU Coil Sanitization and
Energy Efficiency
2019 IAQA Annual Meeting
Acknowledgements
• Alan Wozniak, CIAQP, CIEC
• Dr. Rajiv Sahay, FIAS, CIAQP
• Francisco Aguirre, CIAQP, CIAQC
• Troy Raszka, Communications
Director
2019 IAQA Annual Meeting
Frank “The Grease”
• Content
2019 IAQA Annual Meeting
HVAC: The Lungs of Our
Buildings
• Content
2019 IAQA Annual Meeting
Why Clean The Coils?
• ContentKeeping evaporator and condenser coils of an air conditioning
system clean does more to maintain operating efficiency and
increase equipment life than any other preventive maintenance
procedure.
A regularly scheduled coil cleaning will help keep your
equipment running better and longer.
2019 IAQA Annual Meeting
The Problem: Unhygienic AHUs &
Coils
• Content
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What Conditions Do We Find?
• Content• Dark, Damp, Oftentimes Wet Conditions
• Formations of Endotoxins, Mycotoxins,
Bacteria, Fungi, Pollen, Particulates &
Other Bio-pollutants
• Metal Surfaces & Permeable Materials,
e.g. Fiberglass Insulation
2019 IAQA Annual Meeting
What Bio-contaminants do we find?
Alternaria Aspergillus Cladosporium Curvularia StachybotrysNigrospora
2019 IAQA Annual Meeting
Human Skin Cells
• Content • Bacteria in Air Conditioning
Systems Consume Human Skin
Cells as a Food Source
• Ammonia is a By-product of
Consumption Process
• Body Odor & Urine Smell
2019 IAQA Annual Meeting
“Dirty Sock Syndrome”
• ContentEvaporator coil bio-mass leads to what has been
called “Dirty Sock Syndrome”.
“Medically there is a direct association between
poor indoor air quality in both homes and buildings
and an increase in the prevalence of asthma,
emergency room visits and allergy-type
symptoms.”
- Dr. Janvier Gasana, MD, PHD at Florida International University, Robert Stempel College of
Public Health, Environmental & Occupational Health
2019 IAQA Annual Meeting
“Dirty Sock Syndrome” Litigation
NCAAP v. Arlington, Texas
Schools
2019 IAQA Annual Meeting
Insulating Effect in Fouled
Coils
• Coils Are a Source of Heat Transfer
• Insulating Against Heat Transfer Robs
The System of its Efficiency
• Anything That Contacts Coil Surface
Can Have an Insulating Effect: Dirt,
Grease, Dust, Corrosion, Tobacco
Smoke And, of Course, Microorganisms
2019 IAQA Annual Meeting
A Little Bit of Dirt Makes a BIG Difference
A build up of only 3/16 of
an inch of fouling on the
coils can DECREASE
EFFICIENCY 21%!
The U.S. Environmental Protection Agency
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Deferred Maintenance
Deferred Maintenance = Fouled Air Handling Units + Dirty Ducts
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Deferred Maintenance
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In the Beginning…
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Chemical Rinsing
• Is Not a “Green” or Eco-Friendly Process
• Chemicals can Corrode the Interior of Coils
• Chemicals Rinse into the Waster Water
System
• Only Cleans the Surface of the Coils (60 psi)
• Marginally Improves System Performance
• Very Little to no Measurable Energy Savings
• Minimal IAQ Improvements
Note: Clean coils are not necessarily bright. Typically the brighter the coil’s surfaces, the more metal you have just removed.
2019 IAQA Annual Meeting
Pressure Washing
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And Other Methods
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“The Steam Revolution” in
Cleaning
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Why Steam Works: It Kills
Pathogens
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Why Steam Works: It Removes Pathogens
Heat alone ensures that the
bonding between micro-organisms
and the surface structure is broken
down while the low pressure allows
the steam to deeply penetrate into difficult to reach areas.
2019 IAQA Annual Meeting
Steam Coil Cleaning
• Steam/Particulate Containment Area Set Up
• Coil Cleanliness Verification Test
• HEPA Vacuum Interior of AHU
• Steam up to 350° F and up to 350 psi
• Flush at 55 gal/min to Remove Latent Debris
• Water Extraction Maintained
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Steam Coil Cleaning
Coil Cleanliness Verification Testing measures Delta P/Air Flow before & after cleaning.
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Steam Coil Cleaning
Steam cleans up to 350° F and up to 350 psi to disinfect/flush the coils.
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Heat, Pressure & Time
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Importance of Physical Removal
Before Steam Cleaning
• Surfaces Are Left Thoroughly
and Hygienically Deep Cleaned
• Human Skin Cells, Dust,
Debris, All Physically Removed
• Compared to UV Lighting
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Importance of Physical Removal
Before Steam Cleaning After Steam Cleaning
2019 IAQA Annual Meeting
CABA White Paper: Findings
Parameter
Pre
Treatment
Post
Treatment
% of
Change
Overall
Performance
Microbes
Bacteria (CFU/ml) 154,000 BDL 10099.98% effective
against microbial
contaminantsFungi (CFU/ml) 132,000 60 99.95
Physical
Air Flow (CFM) 250 340 36.00Airflow better by
36.00%
Air Velocity (FPM) 182 250 37.36Air velocity better
by 37.36%
CFU: Colony Forming Unit CFU: Cubic Feet per Minute FPM: Feet per Minute
2019 IAQA Annual Meeting
CABA White Paper: Research
• Field experience and studies show that air conveyance components without proper maintenance become a suitable ecosystem for microbial growth and lead to IAQ problems
• EDLab estimated 368 ft² surface area within an air conditioning coil (17”x 20”x 6.5”,12 fin per inch) that can harbor billions of particulates both biogenic and a-biogenic
• 2.7 Billion CFU/ml/in2 Bacteria
• 2.3 Billion CFU/ml/in2 Fungi (Mold)
2019 IAQA Annual Meeting
CABA White Paper: Impact on Microbes
2019 IAQA Annual Meeting
Georgia Tech Case Study
Units BeforePURE-Steam
AfterPURE-Steam
ImprovementNET
CFM* 6286 8964 2678 or 42.6%
WC* 0.16 0.126 .034 or 22%
Pa 39.9 31.4 8.40 or 22%
BTU 180,000 270,000 90,000 or 50%
Tons 15 22 7 or 46%
CFM: Cubic Feet per Minute WC: Inches in Water Column Pa: Pascal
BTU: British Thermal Unit *NEBB Reporting
2019 IAQA Annual Meeting
Steam Coil Cleaning Conclusions
IAQ Benefits
• Chemical Free
• Disinfects at 280-350° F
• Eradicates Bacteria & Fungi
• Eliminates Musty Odors
• Improves Fresh Air Exchange
Institutional Benefits
• Optimized Performance
• Reduced Work Orders
• Extended Equipment Life
• Energy Savings
• Energy Rebates
2019 IAQA Annual Meeting
Bibliography
• Sahay, Rajiv, Evaluation of Steam Cleaning in AHU Coil
Sanitization and Energy Conservation, Continental Automated
Buildings Association, IS 2013-28, March 2013.
• The Truth about Steam Cleaning, European Cleaning Journal
http://www.europeancleaningjournal.com/magazine/articles/speci
al-features/the-truth-about-steam-cleaning
