© american standard inc. 1997 the trane company la crosse, wisconsin refrigeration system equipment...
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© American Standard Inc. 1997 © American Standard Inc. 1997
The Trane CompanyLa Crosse, Wisconsin
Refrigeration System
Equipment Room DesignRefrigeration System
Equipment Room Design
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards
Standard 34-1992 …
“Number Designation And Safety Classification Of Refrigerants”
Standard 15-1994 …
“Safety Code For Mechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
“Number Designation AndSafety Classification Of Refrigerants”
Purpose? To establish a …
“… simple means of referring to common refrigerants instead of using the chemical name, formula, or trade name.”
“… uniform system for assigning reference numbers and safety classifications to refrigerants.”
ANSI/ASHRAE Standards …
Standard 34-1992
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 34-1992 …
Refrigerant Safety Classifications
Group A3
Group A2
Group A1
Group B3
Group B2
Group B1
higherflammability
lowerflammability
no flamepropagation
lower toxicity higher toxicity
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 34-1992 …
Refrigerant/Blend Data
Refrigerant Chemical Name OrComposition (% By Weight)
Methane Series
CFC (or R) –11 Trichlorofluoromethane 75°F A1 1.6 4,000CFC (or R) –12 Dichlorodifluoromethane –22°F A1 12.0 40,000HCFC (or R) –22 Chlorodifluoromethane –41°F A1 9.4 42,000
Ethane Series
CFC (or R) –113 1,1,2–Trichlorotrifluoroethane 118°F A1 1.9 4,000HCFC (or R) –123 2,2–Dichloro–1,1,1–Trifluoroethane 81°F B1 0.4 1,000HFC (or R) –134a 1,1,1,2–Tetrafluoroethane –15°F A1 16.0 60,000HFC (or R) –152a 1,1–Difluoroethane –13°F A2 1.2 7,000
Azeotropes
R–500 R–12 (73.8) / R–152a (26.2) –27°F A1 12.0 47,000R–502 R–22 (48.8) / R–115 (51.2) –49°F A1 19.0 65,000
NormalBoilingPoint
SafetyGroup
Lbs/1000cu ft
PPMByVol
Refrig Qty Per Occupied Space
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
Purpose? “… to specify safe design, construction, installation,
and operation of refrigerating systems.”
Scope? “This code established safeguards for life, limb, health,
and property and prescribes safety standards.”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
It applies to …
“ … mechanical refrigerating systems and heat pumps used in the occupancies defined in Section 4 and installed subsequently to adoption of this code”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
It also applies to …
“… parts or components added after adoption of this code, or a change to a refrigerant of a different number designation after adoption of this code”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
Finally, it applies to …
“… parts or components replaced after adoption of this code only if they are not identical in function”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
Provides classification criteria for …
Safety group
Occupancy type
Refrigerating system “probability”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
Provides classification criteria for …
Safety group
Occupancy type
Refrigerating system “probability”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 15-1994 …
Safety Group Classification
Standard 34’s refrigerant safety classifications
Group A3
Group A2
Group A1
Group B3
Group B2
Group B1
higherflammability
lowerflammability
no flamepropagation
lower toxicity higher toxicity
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
Provides classification criteria for …
Safety group
Occupancy type
Refrigerating system “probability”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 15-1994 …
Occupancy Classification
Institutional Occupants can’t readily leave without help
Public assembly Where large numbers of occupants can’t vacate quickly
Residential Occupants have complete, independent living facilities
Industrial Occupancy is restricted only to authorized personnel
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 15-1994 …
Occupancy Classification
Commercial Occupants transact business, receive personal
services, or purchase food or other goods
Large mercantile Premises where more than 100 people congregate to
purchase personal merchandise
Mixed Two or more occupancies share the same building
© American Standard Inc. 1997 © American Standard Inc. 1997
ANSI/ASHRAE Standards …
Standard 15-1994
Provides classification criteria for …
Safety group
Occupancy type
Refrigerating system “probability”
“Safety Code ForMechanical Refrigeration”
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 15-1994 …
Refrigerating System Probability
High Probability
Low Probability
SystemDesignation
Cooling Or Heating Source
Air Or SubstanceTo Be Cooled, Heated
Direct
IndirectOpen Spray
Double IndirectOpen Spray
IndirectClosed
IndirectVented Closed
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 15-1994…
Refrigerant Quantity Rules
Public Assembly,Refrigerant System Residential, Commercial,
Group Probability Institutional Large Mercantile Industrial
A1 High 2 1 3Low 4 4 4
A2 High 5 5 3Low 7 7 7
A3 High 9 9 3Low 9 9 7
B1 High 2, 6 1, 6 3Low 4 4 4
B2 High 5, 6 5, 6 3Low 7 7 7
B3 High 9 9 3Low 9 9 7
Applicable Rules By Occupancy Classification
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 15-1994 …
Refrigerant Quantity Rules
Public Assembly,Refrigerant System Residential, Commercial,
Group Probability Institutional Large Mercantile Industrial
A1 High 2 1 3Low 4 4 4
A2 High 5 5 3Low 7 7 7
A3 High 9 9 3Low 9 9 7
B1 High 2, 6 1, 6 3Low 4 4 4
B2 High 5, 6 5, 6 3Low 7 7 7
B3 High 9 9 3Low 9 9 7
Applicable Rules By Occupancy Classification
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 15-1994 …
Refrigerant Quantity Rules
Rule 4 …
“When the quantity of refrigerant in any system exceeds Table 1 amounts, all refrigerant-containing parts, except piping and those parts outside the building, shall be installed in a machinery room constructed in accordance with the provisions of 8.13.”
© American Standard Inc. 1997 © American Standard Inc. 1997
ASHRAE Standard 34-1992 …
Refrigerant Safety Classifications
Refrigerant Chemical Name OrComposition (% By Weight)
Methane Series
CFC (or R) –11 Trichlorofluoromethane 75°F A1 1.6 4,000CFC (or R) –12 Dichlorodifluoromethane –22°F A1 12.0 40,000HCFC (or R) –22 Chlorodifluoromethane –41°F A1 9.4 42,000
Ethane Series
CFC (or R) –113 1,1,2–Trichlorotrifluoroethane 118°F A1 1.9 4,000HCFC (or R) –123 2,2–Dichloro–1,1,1–Trifluoroethane 81°F B1 0.4 1,000HFC (or R) –134a 1,1,1,2–Tetrafluoroethane –15°F A1 16.0 60,000HFC (or R) –152a 1,1–Difluoroethane –13°F A2 1.2 7,000
Azeotropes
R–500 R–12 (73.8) / R–152a (26.2) –27°F A1 12.0 47,000R–502 R–22 (48.8) / R–115 (51.2) –49°F A1 19.0 65,000
NormalBoilingPoint
SafetyGroup
lbs/1000cu ft
PPMByVol
Refrig Qty Per Occupied Space
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Ventilation
Volume requirements for …
Natural ventilation
Mechanical ventilation
Normal rate
Alarm rate
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Ventilation
Remote machinery room …
OccupiedBuilding
OccupiedBuilding
RefrigerationSystem
Lean-to Or Other Structure With Natural Ventilation
More Than20 Feet
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Ventilation
Natural ventilation
For refrigerating systems installed “outdoors, more than 20 ft from [any] building openings …”
F = G0.5
where:F = free opening area (sq ft)G = mass of refrigerant (lbs)
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Ventilation
Normal-rate mechanical ventilation
Needed whenever the equipment room’s occupied
Requirements:
0.5 cfm per sq ft OR 20 cfm per person
Must operate, if necessary for operator comfort, at a volume that limits the temperature rise (T) to no more than 18°F
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Ventilation
Alarm-rate mechanical ventilation
Required to exhaust accumulated refrigerant
Q = 100 × G0.5
where:Q = airflow (cu ft per minute)G = mass of refrigerant (lbs)
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Ventilation
Suggested exhaust fan location …
Exhaust Fan
6 Feet
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Ventilation
Dual-purposeventilation system …
ExhaustAirflow
End View
Plan View
VentilationAirflow
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Refrigeration System Placement
Unobstructed space for inspecting and servicing equipment
Must comply with applicable safety standards and requirements of the presiding regulatory agency
Clear head room not less than 7.25 ft below equipment over passageways
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Refrigeration System Placement
Multiple-chiller equipment room layouts …
Arrangement BArrangement A
ExhaustFan
RefrigerationSystems
ExhaustFan
ExhaustFan
ExhaustFan
RefrigerationSystems
RefrigerationSystems
AirInlet
AirInlet
AirInlet
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Doors, Passageways And Access
Equipment room access limited to authorized personnel
Adequate number and type of doors
No openings to other parts of the building
No “shared” air-handling systems
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Refrigerant Monitoring
“Detector” must …
Be appropriately sensitive to the refrigerant(s) in use
Activate alarm and ventilation at TLV®–TWA
“Threshold Limit Value–Time Weighted Average”
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Refrigerant Monitoring
Sensor location and placement …
Height: 18 inches above the floor
Plan Continuous ventilation: Between the refrigeration
system and room exhaust
Intermittent ventilation: Close to the refrigeration system, between it and the room entrance
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Refrigerant Monitoring
Typical refrigerant monitor installation …
Chiller
RefrigerantMonitor
5 Feet
Roof Or Concrete Floor
Mechanical Equipment RoomOccupied Space
Sample-In Tubing
Particle Filter
12–18 Inches
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Refrigerant Monitoring
Suggested sensor placement for intermittent ventilation …
Identifies refrigerant sampling points
Refrigeration Systems
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Refrigerant Monitoring
Typical multichannel scanner application …
Identifies refrigerant sampling points
Pit
Refrigerant MonitorWith Multichannel Option
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Open-Flame Devices
“No open flames that use combustion air from the machinery room shall be installed where any refrigerant is used.”
Exceptions …
Combustion air is ducted from outside and sealed to prevent refrigerant leakage into the combustion chamber
A refrigerant detector is used to shut down combustion automatically if a refrigerant leak occurs
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
Pressure-Relief Piping
Suggested refrigerantvent piping …
15 Feet AboveGround Level
(Alternate Arrangement)
Exterior Wall
Roof
Purge DischargeVent Line
Rupture DiscAssembly
Flexible SteelConnection
Drip Leg(Length As
Needed)
1/4” FL × 1/4” NPTDrain Valve
Support this pipe!
© American Standard Inc. 1997 © American Standard Inc. 1997
Equipment Room Design
Ventilation
Refrigeration system placement
Doors, passageways and access
Refrigerant monitoring
Open-flame devices
Pressure-relief piping
General requirements
© American Standard Inc. 1997 © American Standard Inc. 1997
equipment room design …
General Requirements
Signs
Changing, charging and storing refrigerants
Self-contained breathing apparatus Two required per equipment room
Emergency shutdown procedure
General maintenance
An American-Standard Company
®