ASHRAE Standards 34,

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PLEASE MUTE CELL PHONES
ASHRAE Standards 34, 147 and 15for Large HVAC
Systems
Julian de Bullet Director of Industry
Relations McQuay International 703-395-5054
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(No Transcript)
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What is a Refrigerant?

• 1. In a refrigerating system, the medium of heat
  transfer which picks up heat by evaporating at a
  low temperature and pressure, and gives up heat
  on condensing at a higher temperature pressure.
• 2. (Refrigerating fluid) fluid used for heat
  transfer in a refrigerating system which absorbs
  heat at a low temperature and low pressure of the
  fluid and transfers heat at a higher temperature
  and higher pressure of the fluid, usually
  involving changes of state of the fluid.
• Ref ASHRAE Terminology of Heating, Ventilation,
  Air Conditioning, Refrigeration

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History of Refrigerants

• 1830s - Jacob Perkins - Vapor Compression (ether)
• 1851 - John Gorie - Patent for Vapor Compression
  Cycle
• 1859 R-717 / R-718 (Ammonia / Water)
• 1866 CO2 - Naval Applications
• 1873 - R-717 (Ammonia) Commercial Refrigeration -
  Karl Linde
• 1875 - R-764 (Sulfur dioxide)
• 1920s -R-600a (Isobutane) R-290 (Propane)
• 1922 - Willis Carrier - R-1130 (Dielene)
• 1926 - R-30 (Methylene Chloride)

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Challenged to Find Refrigerant

• Non-flammable
• Good Stability
• Low Toxicity
• Atmos Boiling Point between - 40 32 oF

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Common Refrigerants in 1920s
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Toxicity - Best Minds Tried to Solve
Solving Problem of Toxicity was a Large Problem
to Development of Refrigeration
1927 - Leo Szilard Albert Einstein Improved on
von Platen / Munters Absorption
Design Electromagnetic Pumping Patent
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Fluorocarbons

• CFCs, HCFCs and HFCs
• Limited Combinations
• Adding Chlorine Or Bromine Increases ODP
• Adding Fluorine Increases GWP
• Adding Hydrogen Increases Flammability And Lowers
  Atmospheric Lifetime

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Enterthe 70sthe Scientists!!!!
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Montreal Protocol

• 1970s.Rowland And Molina Theory Suggests Ozone
  Depletion In Upper Atmosphere
• HVAC MANUFACTURERS GO CRAZY
• 1985 Antarctic Ozone Depletion Observed
• 1987 Montreal Protocol Signed
• Included Phase Outs For Specific Chemicals In
  Developed Countries 1974

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Phase Outs-Developed Countries

• Montreal Protocol
• HCFC Schedule
• 1996 Cap (1989 HCFC Production Plus 2.8 Of 1989
  CFC Production)
• 2004 65
• 2010 35
• 2015 10
• 2020 0.5 No New Equip.
• 2030 0

• USA - EPA
• 2004 End Production R-141B
• Lower Cap For R-22 to 65
• 2010 Service Only For R-22
• 2015 10 For R-22
• 2020 End Production For R-22
• Service Only For R-123
• 2030 End Production For R-123

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Guideline 3

• Reducing Emission of Halogenated Refrigerants in
• HVAC R Systems
• First published in 1990 for CFC Refrigerants only
• Next re-published in 1996- included HCFCs
• Design Good practices included
• Compressors
• Shaft Seals
• Vibration
• Isolation Condensers Evaporators
• Piping Connections
• Valves
• Purging Devices
• Prevention of Vacuum Systems and Leak Test
  Pressurization Systems
• Refrigerant recovery
• MINIMIZE RELEASES OF HALOGENATED REFRIGERANTS

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Clean Air Act-1998

• EPA Published a proposed rule Fall 1997
• Reduce Emissions Rate on New Equipment?
• Fix Leaks or be FINED 25,000 per day
• Chiller Leakage rates have come down
• Negative Pressure- 15
• Positive Pressure-8
• New Chillers- World Bank- 5 or less

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Results?

• It Worked
• Over 30,000 CFC Chillers are still in service
• What about the New Refrigerants?

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ASHRAE Standard 34-2004
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ASHRAE Standard 34 History

• Describes a shorthand way of naming
  refrigerants and assigning safety classifications
  based on toxicity and flammability data
• First Published in 1978
• Now on Continuous Maintenance
• 2004 Edition incorporates many new refrigerants,
  blend compositions and tolerances.

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ASHRAE 34 SAFETY GROUPS
B3
A3 Propane Butane
High Flammability LowFlammability No
FlamePropagation
A2 R-142b, 152a
B2 Ammonia
A1 R-11, 12, 22, 114, 500, 134a
B1 R-123, SO
2
Lower Toxicity
Higher Toxicity
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Anything new?

• The Standard is under continuous maintenance..
• Many additional compositions have been added by
  addenda and assigned Refrigerant Numbers..

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ASHRAE Standard 15
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ASHRAE Standard 15

• What is ASHRAE 15?
• An industry standard that specifies safe design,
  construction, installation, and operation of
  refrigerating systems
• Establishes safeguards for life, limb, health,
  and property, and prescribes safety standards

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ASHRAE Standard 15

• Requirements
• Based on 3 Classifications
• Occupancy
• Refrigerating System
• Refrigerant

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ASHRAE Standard 15

• Occupancy Classifications - Ability to Respond
  to Exposure
• Institutional - Assistance Required
• Public Assembly - Large Numbers
• Residential - Sleeping
• Commercial - Business Transactions
• Large Mercantile - 100 Persons or More
• Industrial Refrigerated Rooms - Access
  Controlled
• Mixed - Two or More in Same Building

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ASHRAE Standard 15

• Refrigerating System Classification
• High Probability - Leak Can Enter Occupied Space
• Low Probability - Leak Cannot Enter Occupied
  Space

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ASHRAE Standard 15

• Restrictions on Refrigerant Use - Section 7
• Standard 15 Gives Rules based on Occupancy,
  System, Refrigerant Classification
• 3 kg or Less of Flammable Refrigerants may be
  used in Listed Equipment

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Defining the Needs of a Machinery Room

• Considerations should include
• safety
• energy efficiency minimums
• temperature control requirements
• reliability/redundancy
• serviceability
• accommodating future expansions
• Process Safety Management

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Machinery Room Ventilation Functions

• Purges refrigerant vapor from the machinery room
  in emergency situations
• For Ammonia - attempts to prevent the
  concentration of from reaching the lower
  flammability limit
• Purges to prevent concentration from exceeding
  toxicity limits
• A2 Refrigerants - minimizes the probability of a
  deflagration
• Limit excessive temperature rise due to
  equipment-generated heat

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Machinery Room Ventilation Functions

• Ventilation for occupants
• Facilitates maintaining the machinery room under
  negative pressure
• Enhances refrigerant sensor responsiveness

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Emergency Ventilation

• A high ventilation rate that attempts to purge
  refrigerant vapor from the machinery room during
  a leak
• Initiated by
• manual switch outside the machinery room door
• refrigerant sensor in machinery room
• reset requires manual intervention

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Non-Emergency Intermittent

• Help limit temperature rise of machinery room due
  to
• heat produced by motors
• heat given off by other equipment (hot gas
  piping, oil separators)
• heat gain through exterior walls
• Initiated by
• thermostat

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Last-Non-Emergency Continuous

• Helps maintain machinery room under negative
  pressure
• Provides ventilation air for room occupants
• Continual movement of air through room helps keep
  refrigerant detectors responsive
• Initiated by
• whenever the machinery room is operational
• during occupancy

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Ventilation Intake/Exhaust Placement

• Inlet location for exhaust fans should consider
  where vapors will concentrate
• Exhaust fan location should consider prevailing
  weather conditions and surrounding buildings
• Avoid recirculation between inlets and outlets
• Intake/exhaust locations should facilitate good
  scavenging of air through machinery room

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Ventilation Operation Maintenance

• Recognize the critical importance of this safety
  system
• Items requiring attention on a scheduled basis
• Ventilation fan(s) air intakes operable in
  all modes?
• Machinery room pressure relationship is
  machinery room under negative pressure?
• Refrigerant detectors are the detector(s)
  functioning properly
• Controls check the control sequences and modes

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Electrical Shutdown for Class 2 3

• Removes all non-classified electrical equipment
  from operation at high flammable refrig
  concentrations
• motors, motor control centers, floats, switches,
  etc.
• Why? It reduces likelihood of deflagrations
• All equipment remaining operational should be the
  appropriate classification
• ventilation fans, emergency lighting, alarms,
  other equipment

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Other Safety Systems

• Eyewash and shower stations
• Passive containment for recirculators/vessels
• diking
• drain to temporary holding tank
• Tie ammonia detection and fire protection alarms
  into auto paging system
• Machinery room secured 24X7 with key card access

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Eye Wash Decon Showers
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Pressure Relief Valves (PRV)

• A normally closed pressure-actuated valve set to
  open at a pre-determined upstream pressure

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Rupture Disks

• A means of relieving pressure by use of a member
  (usually a circular disk) that physically breaks
  when its design pressure is exceeded and does not
  reclose.

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Three-way Valves

• Permits positive isolation of relief valve for
  servicing

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Relief Piping Length Limits(ASHRAE Standard 15 -
2004)

• L equivalent length of pipe (ft)
• Cr rated capacity as stamped on relief
  device (lb/min)
• f friction factor
• d inside diameter of pipe (in)
• Po allowed backpressure at relief valve outlet
  (psia)
• P2 absolute pressure at outlet of discharge
  piping (psia)
• APPENDIX H

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Relief Valve OM

• Vent lines to atmosphere
• protect from moisture incursion
• be capable of draining condensate
• be capable of draining rainwater
• Inspect outlets to insure they are free from
  obstructions
• watch out for those hornet nests
• Do internal visual inspections of your PRVs

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Relief Valve OM

• Be sure you install the correct rating valve
• check the valve itself not just the box
• check the valve against the vessels rating
• Use caution when replacing valves on headered
  systems
• a PRV in service could lift

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Relief Valve OM

• If a PRV lifts
• replace it ASAP if it re-seals
• replace it immediately if it does not reseal
• IIAR 2 limits PRV service life no more than 5 yrs
• an inspection/evaluation program can allow
  extension (or reduction) of the interval
• recent OSHA lawsuit may change approach to PRVs

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Mechanical Room Safety Check
Location of inlet vents in relation to exhaust
outlets ?
Location of roof drains ?
Rupture disc outlet locations ?
Is there a tight seal on doors ?
Purge vents to outside ?
Are safety rupture lines the right size ?
Is access to mechanical room restricted ?
Are drain valves connected to evacuation devices ?
Are there any pit areas in the room ?
Where do the floor drains empty to ?
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Mechanical Room Per ASHRAE 15
Relief discharge shall be located not less than
20 from ventilation opening and not less than
15 above ground level (9.7.8)
All indoor machinery rooms must be vented to
the outdoors utilizing mechanical ventilation
Purge systems and relief devices must be vented
to outside (8.14)
Access to mechanical room shall be
restricted. Tight fitting doors opening outward
(self closing if the open into the
building) adequate in number to ensure freedom
of escape. No other openings that would permit
passage of escaping refrigerant (8.3)
Refrigerant sensors are located in areas
where refrigerant vapor from a leak will be
concentrated so as to provide warning at
concentration not exceeding the refrigerant
TLV-TWA
The total amount of refrigerant stored in
a machinery room in all containers not
provided with relief valves piped in accordance
with standard shall not exceed 330 lb.(11.5)
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Sample Sensor Locations
Entrance / Exits
Refrigerant Storage

Just Above floor Next to Chillers
Drains
Pits
Examples not part of standard
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Mechanical Room Per ASHRAE 15
Periodic tests of detectors, alarms ventilation
must be performed in accordance with
manufactures recommendations and/or
local jurisdiction. (10)
Mechanical room should be dimensioned for
easy access to all parts and adequate space for
service, maintenance, and operation. Clear head
room of not less than 7.25 below equipment
situated over passageways. (8.11)
No open flames that use combustion air from the
machinery room (boilers) can be located within
the mechanical as long as the combustion air is
ducted from the outside to the boiler or
shut down sensors are installed (8.12)
A change in the type of refrigerant in a system
shall not be made without the notification of the
authority having jurisdiction, the user and due
observance of safety requirements.
The refrigerant being considered shall be
evaluated for suitability (5.3)
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ASHRAE Standard 15

• Recent Changes
• No Oxygen Containing Test Gases
• Relief Valve Piping
• SCBA Not Required

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ASHRAE Standard 15

• NOT - Recent Change (Required since 1934)
• No Open Flames or Combustion Equipment with
  Refrigerant Containing Equipment
• Exceptions
• Ducted Combustion Air
• Refrigerant Detector Shuts Down Combustion
  Process
• R-744 (CO2) or R-718 (H2O)
• R-717 (ammonia) with Engine Drive

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ASHRAE SP-93
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IIAR 2
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ASHRAE Standard 147-2002

• Reducing the Release of Halogenated Refrigerants
  from HVAC R Systems
• Replaces Guideline 3
• Includes HFC Refrigerants
• New Initiatives
• ARI- Responsible Use Guideline for Minimizing
  Fluorocarbon Emissions in Manufacturing
  Facilities

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Ideal Application
Innovative Design Award
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Thank You