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IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth
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IAQ & Ventilation - A Baker\’s Dozen IAQA Ft. Worth

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Describes common problems with HVAC systems, based on the author\’s experience over the past 20+ years.

Describes common problems with HVAC systems, based on the author\’s experience over the past 20+ years.

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  • Review and bring literature on Oxine (SO2?). See article from IE Review. Bring samples of Imcoa, literature on Armaflex, Fosters.
  • 1836 Tredgold: 4 CFM/person to purge CO2 and remove body moisture [jokingly- to keep kerosene lamps lit (forget the canary!)] 1865 Nightingale (misspelled above): during Crimean War, served at Barrack Hospital in Turkey [1854-1856] (England, France and Sardinia come to the aid of Turkey against Russia); similar observations regarding poorly -vs- well-ventilated hospitals during US Civil War 1895 Billings, MD: journal article “Ventilation and Heating”; 60 CFM if primary concern is the spread of disease (specifically, tuberculosis), 30 CFM adequate for comfort; and an ASHVE requirement (founded in 1894) “adopted the view that engineers were ready to accept the ideas of hygienists and physiologists” of 30 CFM/occ as the minimum ventilating rate. 1914 ASHVE: proposed model law called for 30 CFM/occ 1922 Adopted by 22 State bldg codes: 30 CFM/occ 1934 Lehmberg: at Harvard University, under contract from ASHVE; published in ASHVE Transactions 1935; first odor study: acceptable at 20 CFM/occ with lower temps, 30 CFM/occ required for higher temps 1936 Yaglou: Constantin Yaglou continued Lehmberg’s work, also at Harvard, and also sponsored by ASHVE Found that grade school children required more ventilation: 50% more ventilation required if children had gone 6.5 days without a bath and change of underwear; 33% more required for adults one week after a bath ASA 1946: American Standards Association Std A53.1 “Light and Ventilation” required 10 CFM/occ of exhaust for ventilation and removal of heat from lighting fixtures to reduce heating load during the cooling season ASA 1966: assigned responsibility for mechanical ventilation section to ASHRAE; resulting in Std 62 in 1973
  • Transcript

    • 1.
      • IAQ and Ventilating Systems:
      • Common Findings -- A Baker’s Dozen
      • Fort Worth, Texas
      • Omni Fort Worth and Fort Worth Convention Center
      • February 25, 2009
      • Presented by:
      • Wane A. Baker, P.E., CIH
      • Division Manager, Indoor Air Quality
      • MICHAELS ENGINEERING INC.
      • 608/785-1900
      “ Real Professionals. Real Solutions.” IAQA 12 th Annual Meeting & Indoor Air Expo IAQA 12th Annual Meeting & Indoor Air Expo, February 24-26, 2009, Fort Worth, Texas fasdjdflkjsa
    • 2.
      • 1. Previous building codes
      • 2. Energy conservation measures
      • 3. Exhaust/relief provisions overlooked
      • We’ll come back to the first three a bit later . . .
      • 4. Deferred maintenance
      • Let’s take a closer look . . .
      IAQ and Ventilating Systems: Common Findings -- A Baker’s Dozen
    • 3. 4. Deferred Maintenance
      • A proposed definition:
      • “ Deferred maintenance is a premeditated plan that assures the controlled self-destruction of your facility.”
      • Maintenance of ventilation systems is one area where the old adage, “If it ain’t broke, don’t fix it” , simply does not apply.
    • 4.
      • Deferred Maintenance:
      • More than Replacing Worn Belts
    • 5. 4. Deferred Maintenance: HVAC Hygiene is Sacrificed
    • 6.
      • Deferred Maintenance: Is your building full of interior duct liner?
    • 7.
      • Deferred Maintenance: Is your building full of interior duct liner?
    • 8.
      • Deferred Maintenance: Is your building full of interior duct liner?
    • 9.
      • Deferred Maintenance: Is your building full of interior duct liner?
    • 10.
      • Deferred Maintenance: Is your building full of interior duct liner?
    • 11. 4. Deferred Maintenance: Debris in the Fan?!?
    • 12.
      • 5. Remodeling: storeroom now an office
      • 6. Commissioning: protect your investment!
      • 7. OA dampers set visually or by % of signal
      • 8. Controls require calibration
      • 9. Shut-off VAV boxes
      • 10. OA distribution in heat pump systems
      • 11. Control of OA in VAV Systems
      • 12. Inadequate filtration
      • 13. Combinations yield negative synergies
      • Let’s take a closer look at the last four . . .
      IAQ and Ventilating Systems: Common Findings -- A Baker’s Dozen (cont’)
    • 13. 10. OA Distribution in Heat Pump Systems
    • 14. 10. OA Distribution in Heat Pump Systems
    • 15.
      • OA Distribution in Heat Pump Systems
      • Common shortcomings in heat pump systems:
        • Inadequate distribution of outdoor air
            • Outdoor air must be supplied within the “capture zone” of each unit’s return air side
        • Lack of adequate humidity control
            • Equipment sensible heat ratio is high
            • Return air <60 degF will cause typical unit to shut down (trips out: low head)
              • Outdoor air must be pre-conditioned both in heating and cooling season!
    • 16. 11. Control of Outdoor Air in VAV Systems 980-RP: Techniques for Measuring and Controlling Minimum Outdoor Air Intake Rates in VAV Systems September 1997 - January 1999 The Regents of the University of Colorado Principal Investigator, Moncef Krarti TC 1.4 Control Theory and Application “ The objective of this research project is to . . . compare various techniques for measuring and controlling minimum outdoor air intake rates in VAV systems. Based on the results of these analyses, a set of guidelines will be provided to assess . . . each technique.” ASHRAE Research Project
    • 17. 11. Control of Outdoor Air in VAV Systems (Transactions #4369: 2000 Summer Meeting in Mpls.) “ Experimental Analysis of Measurement and Control Techniques of Outside Air Intake Rates in VAV Systems” Abstract: “…control strategies using the direct measurement of the outside airflow from an averaging pitot-tube array or an electronic thermal anemometer provided the best ventilation control.” Discussion: “In cases where there is not sufficient unobstructed OA duct length to ensure uniformity of airflow profiles, … a dedicated minimum OA duct is recommended.” ASHRAE 980-RP
    • 18. 12. Inadequate Filtration
    • 19. 12. Inadequate Filtration
    • 20.  
    • 21. 12. Inadequate Filtration
    • 22. 12. Inadequate Filtration: Should I use Antimicrobial Filters? ( ASHRAE Journal , December 2000) “ Efficacy of Antimicrobial Filter Treatments” Three treatments were studied: “…an amine neutralized phosphoric ester, a quaternary ammonium compound, and an iodine compound.” Results: “Little or no difference existed in the numbers of xerophilic fungi eluted from the…treated and untreated filters…” And: “…new filters generally are a hostile environment for microbial growth whether treated with antimicrobial agent or not.” Conclusions: “…two of the three antimicrobials inhibited the growth of the test organisms on new filters at all ERHs tested; the third did not [Table 2].” And: “…all of the filters, except for one, did permit the growth of fungi after dust loading [Table 3].” ASHRAE 909-RP
    • 23. 12. Inadequate Filtration: Should I use Antimicrobial Filters? ( Indoor Environment Connections , November 1999) “ ASHRAE Study Shows Mixed Results for Antimicrobial Filters” Products identified: “Antimicrobial 1 is Sporax …Antimicrobial 2 is Intersept …Antimicrobial 3 is Aegis Microbe Shield …” Per Al Veeck, Chairman of the ASHRAE Project Monitoring Committee: “When you find filters with biological growth, it’s always due to a problem upstream in the system. If that problem were fixed, there would be no need for an antimicrobial filter . ” And: “… in hot, humid climates the use of an antimicrobial filter may prove beneficial as part of a holistic approach to IAQ.” ASHRAE 909-RP
    • 24. 13. Combinations Yield Negative Synergies Deferred Maintenance + Inadequate Filtration +++
    • 25. 13. Combinations Yield Negative Synergies Deferred Maintenance + Inadequate Filtration +++
      • “ Porous insulation near AHU drain pans and cooling coils, [and] in air supply ducts immediately downstream of the cooling coil plenum . . . is most likely to become a strong microbial amplification site.”
      • Ref.: Morey, P.R., and C.M. Williams. 1991. “Is Porous Insulation Inside an HVAC System Compatible with a Healthy Building?” In Healthy Buildings . Atlanta: ASHRAE (IAQ ‘91)
    • 26. Proposed solutions: Duct Liner / Interior Insulation
      • “ Remedial measures that may be used . . . include the following:”
      • “ Upgrade the efficiency of AHU filter banks.”
      • “ The airstream surface of contaminated insulation may be [HEPA] vacuumed . . .”
      • “ Contaminated insulation may be covered with a sealant.” (Foster 40-20, ToughCoat, IAQ6000 are not intended nor registered for this purpose)
      • “ The use of biocides is never a solution to this problem.” (e.g., Oxine)
      • “ The microbiologically contaminated insulation can be removed and replaced with new external insulation.” (Consider Armaflex or Imcoa)
      • Ref.: Morey, P.R., and C.M. Williams. 1991. “Is Porous Insulation Inside an HVAC System Compatible with a Healthy Building?” In Healthy Buildings . Atlanta: ASHRAE (IAQ ‘91)
    • 27. 13. Combinations Yield Negative Synergies Deferred Maintenance + Inadequate Filtration
    • 28. 13. Combinations Yield Negative Synergies Deferred Maintenance + Inadequate Filtration
    • 29. 13. Combinations Yield Negative Synergies Deferred Maintenance + Inadequate Filtration
    • 30. IAQ and Ventilating Systems Problems Found with All System Types 1. Previous building codes 2. Energy conservation measures 3. Provision for exhaust/relief overlooked
    • 31.
      • “ Standard practice has established that 30 cu.ft. per minute or 1,800 cu.ft. per hour [of fresh air] per occupant should be provided.”
      • Ref: Standard Practice in Sheet Metal Work , National Association of Sheet Metal Contractors, Pittsburg, PA 1929
      IAQ and Ventilating Systems 1. Previous Building Codes Building Codes
    • 32.
      • Historical Minimum Ventilation Rates
      IAQ and Ventilating Systems 1. Previous Building Codes ASHVE 1914 22 State Codes 1922
    • 33.
      • ASHRAE 62-73 was adopted by the Minnesota State Building Code in 1976
        • Required 10 cfm per occupant for classrooms, but could be reduced to 5 cfm per occupant with temperature control and filtration
      IAQ and Ventilating Systems 1. Previous Building Codes
    • 34.
      • ASHRAE 62-1989 was adopted by the Minnesota State Building Code in May 1991
        • Requires 15 cfm per occupant for classrooms, 20 cfm per occupant for offices
      • ASHRAE 62-1981 was never adopted by the State of Minnesota
        • Introduced the concepts of an Indoor Air Quality Procedure and smoking vs. non-smoking OA supply rates
      IAQ and Ventilating Systems 1. Previous Building Codes
    • 35.
      • Just to keep things interesting:
      • Prior to May 1991, a conflict appeared between the Minnesota State Energy Code (5 cfm/occupant) and the Mechanical Code (7-1/2 cfm/occupant)
      IAQ and Ventilating Systems 1. Previous Building Codes Building Codes
    • 36.
      • The history of building codes in the State of Wisconsin has left a legacy of schools, offices and commercial spaces ventilated at 1/3 to 1/2 of the current minimum rate recommended by ASHRAE:
      • Wisconsin Administrative Code, Comm. 64.05(2)(a) [Table 64.05]: changed from 5 cfm/occupant to
      • 7-1/2 cfm/occupant in April 1996, but was “stayed” until April 1997.
      IAQ and Ventilating Systems 1. Previous Building Codes Building Codes
    • 37.
      • In Iowa, a state building code was enacted for all construction after January 1, 1978
        • Not a mandatory code throughout the state
        • Does apply to all state-owned buildings
        • Iowa law allows cities to adopt the SBC, any other building code, or no code at all
          • ~30 cities have adopted the SBC
          • ~50 have enacted some other form of a code
          • >800 towns and cities have no code at all
      IAQ and Ventilating Systems 1. Previous Building Codes
    • 38.
      • Iowa state code adopts the Uniform Building Code (UBC) by reference
        • “ E Occupancy”: Educational
        • “ B Occupancy”: Business
        • “ A Occupancy”: Assembly
          • Requires 15 CFM/occ for classrooms, offices, auditoriums
          • Occupant density poorly defined
            • (Table 10-A Min. Egress Requirements often used)
      IAQ and Ventilating Systems 1. Previous Building Codes
    • 39.
      • Causes of Indoor Air Quality Problems in Schools, Summary of Scientific Research
      • (C. Bayer, S. Crow, J. Fischer, DOE/ORNL, January 1999)
        • “ Most IAQ problems in school facilities can be avoided by:
        • Providing adequate outdoor air ventilation on a continuous basis (15 cfm per student)
        • Controlling … relative humidity between 30 and 60%
        • Providing effective particulate filtration…”
      IAQ and Ventilating Systems 1. Previous Building Codes - Solutions
    • 40.
      • “ But how can you expect my existing buildings to provide the recommended 15 cfm/occupant?”
        • • This can be achieved by many HVAC systems during most of the year
        • • Consider design temperature of -15°F vs. hours of occurrence & time of day that the temperature extremes occur
        • • Engineering study can define an improved operational strategy
      IAQ and Ventilating Systems 1. Previous Building Codes - Solutions
    • 41.
      • Rising energy costs in 1970s led to the implementation of many forms of energy conservation measures (ECMs)
      • Reflected in development of energy codes, changes in ASHRAE Standard 62
      IAQ and Ventilating Systems 2. Energy Conservation Measures
    • 42.
      • Perception
        • Improving IAQ always means higher operating costs
      • Reality
        • Appropriate and innovative engineering can provide a balance
      IAQ and Ventilating Systems 2. Energy Conservation Measures
    • 43.
      • Some ECMs were implemented without due regard for the health of occupants
        • Boarded up OA intakes
        • Additional controls
        • Demand Controlled Ventilation (DCV) by CO 2 without calibration and maintenance
      IAQ and Ventilating Systems 2. Energy Conservation Measures
    • 44. IAQ and Ventilating Systems 2. Energy Conservation Measures
    • 45.
      • Solutions
        • Assure delivery of OA per original design
        • Look for opportunities to increase efficiency and incorporate energy recovery
      IAQ and Ventilating Systems 2. Energy Conservation Measures
    • 46.
      • A personal challenge!
      • Electrical circuit analogy
        • Four “legs” of the circuit must be complete!
        • Supply, return, OA intake, exhaust/relief
      • Backdraft dampers are unreliable in the long term
      IAQ and Ventilating Systems 3. Exhaust/Relief Overlooked
    • 47.
      • Systems generally designed to keep building neutral or at a slight positive pressure
        • Reduces drafts -- yields energy savings
        • Controls moisture problems:
          • In winter -- condensation on windows
          • In summer -- moisture in wall cavities
      IAQ and Ventilating Systems 3. Exhaust/Relief Overlooked
    • 48.
      • -0.004” WC: produce drafts of 150 ft/min
      • -0.05” WC: combustion equipment may backdraft
      • -0.10” WC: airflow at axial fans reduce (doors difficult to open; unchecked doors slam)
      IAQ and Ventilating Systems 3. Exhaust/Relief Overlooked
          • Conversely, negative pressure results from operation of exhaust fans without adequate make-up air:
      Radon and bioeffluents from concealed microbiological amplification sites may be drawn into occupied spaces, resulting in adverse health effects
    • 49. Good Design in Packaged Units?
    • 50. Good Design or Symmetry?
    • 51. Are Building Codes Sufficiently Protective?
    • 52. IAQ and Ventilating Systems: Common Findings -- A Baker’s Dozen
      • Thank you!
      • Wane A. Baker, P.E., CIH
      • MICHAELS ENGINEERING INC.
      • St. Paul, La Crosse, Milwaukee, Green Bay
      • 608/785-1900
      • Email: [email_address]
      • Website: www.MichaelsEngineering.com
      QUESTIONS?? “ Real Professionals. Real Solutions.”

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