AAON RZ Series Owner's manual

RZ SERIES
(45-240tons)
Packaged Rooftop Units & Outdoor Air Handling Units
Installation, Operation,
& Maintenance
oDo not store gasoline or other flammable
vapors and liquids in the vicinity of this or any
other appliance
oWHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.

Do not touch any electrical switch; do not
use any phone in your building.
Leave the building immediately.

Immediately call your gas supplier from a
phone remote from the building. Follow the
gas supplier’s instructions.

If you cannot reach your gas supplier, call
the fire department.
oStartup and service must be performed by a
Factory Trained Service Technician.
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings
exactly could result in serious
injury, death or property damage.
Be sure to read and understand
the installation, operation and
service instructions in this manual.
Improper installation, adjustment,
alteration, service or maintenance
can cause serious injury, death or
property damage.
A copy of this IOM mustbe kept
with the unit.
WARNING

3
Table ofContents
Table of Contents
AAON® RZ Series Features and Options Introduction ............................................................. 7
Safety...................................................................................................................................... 8
RZ Series Feature String Nomenclature...................................................................................14
General Information ...............................................................................................................26
Codes and Ordinances.........................................................................................................27
Receiving Unit....................................................................................................................27
Storage...............................................................................................................................28
Access Doors......................................................................................................................28
Wiring Diagrams ................................................................................................................28
Installation .............................................................................................................................28
Locating Units....................................................................................................................28
Curb Installation .................................................................................................................29
Lifting the Unit...................................................................................................................30
Duct Connection.................................................................................................................33
Reassembling Split Units ....................................................................................................34
Refrigeration Split Installation Procedure.......................................................................35
Electrical Connection of Split Units................................................................................36
Outside Air Rain Hood .......................................................................................................36
End Flashing Installation.....................................................................................................36
Vestibule Exhaust Fan ........................................................................................................37
Electrical............................................................................................................................38
Variable Speed Compressors..........................................................................................40
Condensate Drain Piping.....................................................................................................41
Draw-Through Coils ...........................................................................................................41
Startup ...................................................................................................................................43
Filters.................................................................................................................................43
Cartridge Filter Installation...........................................................................................43
HEPA Filters.................................................................................................................43
Metal Mesh Filters.........................................................................................................43
Air Flow Monitoring...........................................................................................................44
Supply, Return, and Exhaust Backward Curved Fans ...........................................................44
Airflow Adjustment.........................................................................................................44
Back Draft Damper Setup ...................................................................................................46
Adjusting Refrigerant Charge..............................................................................................46
Before Charging ............................................................................................................46
Checking Liquid Sub-Cooling.........................................................................................47
Checking Evaporator Superheat.....................................................................................47
Adjusting Sub-cooling and Superheat Temperatures........................................................49
Freeze Stat Startup..............................................................................................................50
Refrigerant Filter Driers......................................................................................................50
Suction Filter Removal Instructions.....................................................................................51
VFD Controlled Condenser Fan Startup...............................................................................52

4
Low Sound Condenser Fan EC Motor Startup......................................................................52
Operation ...............................................................................................................................53
Packaged DX Cooling Operation.........................................................................................53
Indirect Gas Heater Operation .............................................................................................53
Electric Heating Operation..................................................................................................53
Steam or Hot Water Preheating and Heating Operation ........................................................53
Chilled Water or Non-Compressorized DX Cooling Operation.............................................53
Maintenance...........................................................................................................................54
Supply Fans........................................................................................................................54
Lubrication....................................................................................................................54
DX Cooling........................................................................................................................54
Condensate Drain Pans .......................................................................................................54
Filter Replacement..............................................................................................................54
Brazed Plate Heat Exchanger Cleaning................................................................................54
Air-Cooled Condenser ........................................................................................................55
E-Coated Coil Cleaning ......................................................................................................55
Microchannel Coil Cleaning................................................................................................57
Options ..................................................................................................................................59
Heating Coils......................................................................................................................59
Chilled Water Coil..............................................................................................................60
Packaged Direct Expansion (DX) Units...............................................................................60
Evaporator Coil.............................................................................................................61
Condenser Fans.............................................................................................................62
Evaporative Condenser .......................................................................................................62
Evaporative Condenser Location....................................................................................63
Evaporative Condenser Installation................................................................................64
Evaporative Condenser Operation..................................................................................64
Evaporative Condenser Sequence of Operation...............................................................66
Evaporative Condenser Maintenance..............................................................................67
Evaporative Condenser Water Quality............................................................................69
Energy Recovery Units .......................................................................................................71
Aluminum Energy Recovery Wheel.................................................................................71
Polymer Energy Recovery Wheel....................................................................................74
Energy Recovery Wheel General Cleaning......................................................................81
Energy Recovery Wheel Defrost Timer Setting...............................................................83
Gas or Electric Heating .......................................................................................................84
Gas Heating........................................................................................................................85
Piping Sizing Example ...................................................................................................86
Inlet and Manifold Pressures..........................................................................................86
Gas Pressure Regulator & Overpressure Protection Device............................................86
Piping Supports.............................................................................................................87
Additional Gas Piping Considerations............................................................................87
Leak Testing ..................................................................................................................88
Rain Hoods....................................................................................................................89
Gas Heater Operating Instructions.................................................................................90
Gas Heating Maintenance..............................................................................................91

5
Gas Heat Exchanger Removal........................................................................................91
Phase and Brownout Protection Module ..............................................................................92
UV Lights ..........................................................................................................................95
Filter Replacement..............................................................................................................95
Replacement Parts ..............................................................................................................97
Appendix A - Heat Exchanger Corrosion Resistance................................................................98
Appendix B - Thermistor Temperature vs. Resistance Values ................................................100
RZ Series Startup Form ........................................................................................................101
Maintenance Log (E-Coated Coil).........................................................................................108
Literature Change History.....................................................................................................109
G074290 · Rev. A · 220113
Index of Tables and Figures
Tables
Table 1 - Air-Cooled Condenser Unit Clearances 45-240 ton...........................................................29
Table 2 - Evaporative Condenser Unit Clearances 45-240 ton..........................................................29
Table 3 - Mounting Dimensions..................................................................................................33
Table 4 - Nameplate Voltage Markings & Tolerances.....................................................................38
Table 5 - RZ Variable Speed Compressor VFD Frequency Range....................................................40
Table 6 - Draw-Through Drain Trap Dimensions...........................................................................42
Table 7 - Blow-Through Drain Trap Dimensions...........................................................................42
Table 8 - Plenum Fan Set Screw Specifications .............................................................................45
Table 9 - Acceptable Fin & Tube Sub-Cooling and Superheat Temperatures......................................48
Table 10 - Acceptable Microchannel Air-Cooled Condenser Coil Liquid Sub-Cooling Values ..............48
Table 11 - R-410A Refrigerant Temperature-Pressure Chart............................................................50
Table 12 - Filter Drier Maximum Pressure Drop............................................................................50
Table 13 - EC Condenser Fan Cycling Options..............................................................................52
Table 14 - Hot Water Coil Connection Sizes.................................................................................59
Table 15 - Steam Distributing Coil Connection Sizes .....................................................................59
Table 16 - Chilled Water Coil Connection Sizes ............................................................................60
Table 17 - Energy Recovery Wheel Cleaning Frequency.................................................................81
Table 18 - RZ 45-140 ton Electric Heating Capacities ....................................................................84
Table 19 - RZ 145-240 ton Electric Heating Capacities...................................................................84
Table 20 - RZ 45-140 ton Gas Heating Capacities..........................................................................84
Table 21 - RZ 145-240 ton Gas Heating Capacities ........................................................................84
Table 22 - RZ 45-140 ton Unit Gas Piping Connections..................................................................85
Table 23 - RZ 145-240 ton Unit Gas Piping Connections................................................................85
Table 24 - Natural Gas Maximum Piping Capacities (ft3/hr)............................................................85
Table 25 - Propane (kBtu/hr) Maximum Piping Capacities ..............................................................86
Table 26 - Piping Support Intervals..............................................................................................87
Table 27 - Air Disinfection UV Information..................................................................................95
Table 28 - RZ Series Filter Sizes.................................................................................................96
Table 29 - Metal Mesh and HEPA Filter Sizes...............................................................................97

6
Figures
Figure 1 - Lockable Door Handles...............................................................................................28
Figure 2 - RZSeries Unit Orientation...........................................................................................29
Figure 3 - Base Rail Lifting Lug..................................................................................................30
Figure 4 - 4 Point Lift RZ Series Air-Cooled Condenser Unit ..........................................................31
Figure 5 - 8 Point Lift RZ Series Air-Cooled Condenser Unit ..........................................................32
Figure 6 - Curb Mounting ..........................................................................................................33
Figure 7 - Curb Detail................................................................................................................33
Figure 8 - Curb & Steel Mounting Rail with Dimensions ................................................................33
Figure 9 - Unit Base and Sides....................................................................................................34
Figure 10 - Unit Roof Flange Splice Detail ...................................................................................34
Figure 11 - Staggered assembly for refrigeration pipes....................................................................35
Figure 12 - Air Hood Shown in the Open Position .........................................................................36
Figure 13 - Factory Supplied End Flashings..................................................................................37
Figure 14 - Vestibule Exhaust Fan...............................................................................................37
Figure 15 - Motorized Exhaust....................................................................................................37
Figure 16 - Power Block............................................................................................................39
Figure 17 - Draw-Through Drain Trap.........................................................................................41
Figure 18 - Blow-Through Drain Trap..........................................................................................42
Figure 19 - Top Clip and Side Spring Fastener Securing Filters in Place............................................43
Figure 20 - Air Volume Band .....................................................................................................44
Figure 21 - Air Volume Band Tab Locations.................................................................................45
Figure 22 - Securing Air Volume Band Ends.................................................................................45
Figure 23 - Plenum Fan Gap Tolerances.......................................................................................45
Figure 24 - Closed Back Draft Damper ........................................................................................46
Figure 25 - Open Back Draft Damper...........................................................................................46
Figure 26 - Replaceable Core Liquid Filter/Driers Suction Filter......................................................51
Figure 27 - RPE-48-BD filter element..........................................................................................51
Figure 28 - Proper Unit Location.................................................................................................63
Figure 29 - Improper Unit Locations............................................................................................63
Figure 30 - Temporary Drain Components....................................................................................64
Figure 31 - Water Makeup Valve ................................................................................................66
Figure 32 - Evaporative condenser access door..............................................................................68
Figure 33 - Aluminum Energy Recovery Wheel............................................................................71
Figure 34 - Aluminum ERW Purge Sector Location.......................................................................72
Figure 35 - Polymer Energy Recovery Wheel................................................................................74
Figure 36 - Wheel Segment Removal Pattern................................................................................78
Figure 37 - Defrost Timer..........................................................................................................83
Figure 38 - Temperature Dial......................................................................................................83
Figure 39 - Gas Heater Rain Hood...............................................................................................89
Figure 40 - Gas Heater Rain Hood Screws....................................................................................89
Figure 41 - Gas Heat Exchanger..................................................................................................92

7
AAON® RZ Series Features and Options Introduction
EnergyEfficiency
Direct Drive Airfoil Plenum Supply Fans
Variable Speed R-410A Scroll
Compressors
AAON Evaporative Condenser
Airside Economizer
Factory Installed AAONAIRE®Energy
Recovery Wheels
Double Wall Rigid Polyurethane Foam
Panel Construction, R-13 Insulation
Modulating Natural Gas Heaters
Modulating/SCR Electric Heaters
Premium Efficiency Permanent Magnet
Motors
Variable Speed Supply/Return/Exhaust
Fans
Indoor Air Quality
100% Outside Air
Outside Airflow Monitoring
Economizer CO2Override
High Efficiency Filtration
Final Filters, including Gas Heat Systems
UV Lights for Single Pass 90% Air
Disinfection
Double Wall Rigid Polyurethane Foam
Panel Construction, R-13 Insulation
Interior Corrosion Protection
Humidity Control
High Capacity Cooling Coils
Variable Speed Compressors
Factory Installed AAONAIRE Total
Energy Recovery Wheels
Modulating Hot Gas Reheat
Safety
Burglar Bars
Freeze Stats
Phase and Brown Out Protection
Supply/Return Smoke Detectors
Supply/Return Firestats
Remote Safety Shutdown Terminals
Installation and Maintenance
Clogged Filter Switch
Color Coded Wiring Diagram
Compressors in Isolated Compartment
Compressor Isolation Valves
Convenience Outlet
Direct Drive Supply Fans
VFD Shaft Grounding
Hinged Access Doors with Lockable
Handles
Magnehelic Gauge
Service Lights
Sight Glasses
BACnet MSTP with Diagnostics
Remote Start-Stop Terminals
Access Door Windows
Motorized Fresh Air Service Vestibule
SystemIntegration
Chilled Water Cooling Coils
Electric/Natural Gas/LP Heating
Hot Water/Steam Heating Coil
Non-Compressorized DX Coils
Environmentally Friendly
Airside Economizers
Factory Installed AAONAIRE Energy
Recovery Wheels
R-410A Refrigerant
ExtendedLife
5 Year Compressor Warranty
25 Year Stainless Steel Heat Exchanger
Warranty
Interior Corrosion Protection
Polymer E-Coated Coils - 5 Year Coating
Warranty
Stainless Steel Coil Casing
Stainless Steel Drain Pans

8
Safety
ELECTRIC SHOCK, FIRE OR
EXPLOSION HAZARD
Failure to follow safety warnings
exactly could result in dangerous
operation, serious injury, death or
property damage.
Improper servicing could result in
dangerous operation, serious injury,
death, or property damage.
Before servicing, disconnect all
electrical power to the furnace.
More than one disconnect may be
provided.
When servicing controls, label all
wires prior to disconnecting.
Reconnect wires correctly.
Verify proper operation after
servicing. Secure all doors with
key-lock or nut and bolt.
WARNING
WHAT TO DO IF YOU SMELL GAS
Do not try to turn on unit.
Shut off main gas supply.
Do not touch any electric switch.
Do not use any phone in the
building.
Never test for gas leaks with an
open flame.
Use a gas detection soap solution
and check all gas connections and
shut off valves.
CAUTION
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING
Attention must be paid to the following statements:
NOTE - Notes are intended to clarify the unit installation, operation and maintenance.
CAUTION- Caution statements aregiven to prevent actions that may result in equipment
damage, property damage, or personal injury.
WARNING - Warning statements are given to prevent actions that could result in
equipment damage, property damage, personal injury or death.
DANGER - Danger statements are given to prevent actions that will result in equipment
damage, property damage, severe personal injury or death.
Electric shock hazard. Before
servicing, shut off all electrical power
to the unit, including remote
disconnects, to avoid shock hazard or
injury from rotating parts. Follow
proper Lockout-Tagout procedures.
WARNING

9
FIRE, EXPLOSION OR CARBON
MONOXIDE POISONING HAZARD
Failure to replace proper controls
could result in fire, explosion or
carbon monoxide poisoning. Failure to
follow safety warnings exactly could
result in serious injury, death or
property damage. Do not store or use
gasoline or other flammable vapors
and liquids in the vicinity of this
appliance.
WARNING
During installation, testing, servicing,
and troubleshooting of the equipment
it may be necessary to work with live
electrical components. Only a
qualified licensed electrician or
individual properly trained in handling
live electrical components must
perform these tasks.
Standard NFPA-70E, an OSHA
regulation requiring an Arc Flash
Boundary to be field established and
marked for identification of where
appropriate Personal Protective
Equipment (PPE) be worn, must be
followed.
WARNING
ROTATING COMPONENTS
Unit contains fans with moving parts
that can cause serious injury. Do not
open door containing fans until the
power to the unit has been
disconnected and fan wheel has
stopped rotating.
WARNING
CARBON MONOXIDE POISONING
HAZARD
Failure to follow instructions could
result in severe personal injury or
death due to carbon-monoxide
poisoning, if combustion products
infiltrate into the building.
Check that all openings in the outside
wall around the vent (and air intake)
pipe(s) are sealed to prevent
infiltration of combustion products into
the building.
Check that furnace vent (and air
intake) terminal(s) are not obstructed
in any way during all seasons.
WARNING
Unit power supply wire must be only
copper or aluminum.
CAUTION

10
VARIABLE FREQUENCY DRIVES
Do not leave VFDs unattended in
hand mode or manual bypass.
Damage to personnel or equipment
can occur if left unattended. When in
hand mode or manual bypass mode
VFDs will not respond to controls or
alarms.
WARNING
GROUNDING REQUIRED
All field installed wiring must be
completed by qualified personnel.
Field installed wiring mustcomply with
NEC/CEC, local and state electrical
code requirements. Failure to follow
code requirements could result in
serious injury or death. Provide proper
unit ground in accordance with these
code requirements.
WARNING
Electric motor over-current protection
and overload protection may be a
function of the Variable Frequency
Drive to which the motors are wired.
Never defeat the VFD motor overload
feature. The overload ampere setting
must not exceed 115% of the electric
motors FLA rating as shown on the
motor nameplate.
CAUTION
UNIT HANDLING
To prevent injury or death, lifting
equipment capacity must exceed unit
weight by an adequate safety factor.
Always test-lift unit not more than 24
inches high to verify proper center of
gravity lift point to avoid unit damage,
injury or death.
WARNING
Failure to properly drain and vent coils
when not in use during freezing
temperature may result in coil and
equipment damage.
CAUTION
Rotation must be checked on all
MOTORS AND COMPRESSORS of 3
phase units at startup by a qualified
service technician. Scroll
compressors are directional and can
be damaged if rotated in the wrong
direction. Compressor rotation must
be checked using suction and
discharge gauges. Fan motor rotation
mustbe checked for proper operation.
Alterations must only be made at the
unit power connection
CAUTION
Do not use oxygen, acetylene or air in
place of refrigerant and dry nitrogen
for leak testing. A violent explosion
may result causing injury or death.
WARNING

11
WATER PRESSURE
Prior to connection of condensing
water supply, verify water pressure is
less than maximum pressure shown
on unit nameplate. To prevent injury
or death due to instantaneous release
of high pressure water, relief valves
must be field supplied on system
water piping.
WARNING
Always use a pressure regulator,
valves and gauges to control incoming
pressures when pressure testing a
system. Excessive pressure may
cause line ruptures, equipment
damage or an explosion which may
result in injury or death.
WARNING
Do not clean DX refrigerant coils with
hot water or steam. The use of hot
water or steam on refrigerant coils will
cause high pressure inside the coil
tubing and damage to the coil.
CAUTION
To prevent damage to the unit, do not
use acidic chemical coil cleaners. Do
not use alkaline chemicalcoil cleaners
with a pH value greater than 8.5, after
mixing, without first using an
aluminum corrosion inhibitor in the
cleaning solution.
CAUTION
Some chemical coil cleaning
compounds are caustic or toxic. Use
these substances only in accordance
with the manufacturer’s usage
instructions. Failure to follow
instructions may result in equipment
damage, injury or death.
WARNING
Door compartments containing
hazardous voltage or rotating parts
are equipped with door latches to
allow locks. Door latch are shipped
with nut and bolts requiring tooled
access. If you do not replace the
shipping hardware with a pad lock
always re-install the nut & bolt after
closing the door.
CAUTION
Cleaning the cooling tower or
condenser water loop with harsh
chemicals such as hydrochloric acid
(muriatic acid), chlorine or other
chlorides, candamage the refrigerant-
to-water heat exchanger. Care must
be taken to avoid allowing chemicals
to enter the refrigerant-to-water heat
exchanger. See Appendix A - Heat
Exchanger Corrosion Resistance for
more information.
CAUTION

12
WATER FREEZING
Failure of the condenser due to
freezing will allow water to enter the
refrigerant circuit and will cause
extensive damage to the refrigerant
circuit components. Any damage to
the equipment as a result of water
freezing in the condenser is excluded
from coverage under AAON
warranties and the heat exchanger
manufacturer warranties.
OPEN LOOP APPLICATIONS
Failure of the condenser as a result of
chemical corrosion is excluded from
coverage under AAON Inc. warranties
and the heat exchanger
manufacturer’s warranties.
WARNING
WARNING
COMPRESSOR CYCLING
3 MINUTE MINIMUM OFF TIME
To prevent motor overheating
compressors must cycle off for a
minimum of 3 minutes.
5 MINUTE MINIMUM ONTIME
To maintain the proper oil level
compressors must cycle on for a
minimum of 5 minutes.
The cycle rate must not exceed 7
starts per hour.
WARNINGWARNING
UV LIGHTS
Never expose eyes or skin to UVC
light from any source, as personal
injury may result. Wear gloves, face
shield/glasses (per ANSI Z87.1) and
cover all exposed skin.
WARNING

13
1. Startup andservice must be performed by
a Factory Trained Service Technician.
2. Use only with type of the gas approved
for the furnace. Referto the furnace rating
plate.
3. The unit is for outdoor use only. See
General Information section for more
information.
4. Provide adequate combustion ventilation
air to the furnace. If a vent duct extension
is used, a class III approved vent is
required. See the Locating Units and Gas
Heating sections of the Installation
section of the manual.
5. Always install and operate furnace within
the intended temperature rise range and
duct system external static pressure (ESP)
as specified on the unit nameplate.
6. The supply and return air ducts must be
derived from the same space. It is
recommended ducts be provided with
access panels to allow inspection for duct
tightness. When a down flow duct is used
with electric heat, the exhaust duct must
be an L shaped duct.
7. Clean furnace, duct, and components
upon completion of the construction
setup. Verify furnace operating
conditions including input rate,
temperature rise, and ESP.
8. Every unit has a unique equipment
nameplate with electrical, operational,
and unit clearance specifications.
Always refer to the unit nameplate for
specific ratings unique to the model you
have purchased.
9. READ THE ENTIRE INSTALLATION,
OPERATION, AND MAINTENANCE
MANUAL. OTHER IMPORTANT
SAFETY PRECAUTIONS ARE
PROVIDED THROUGHOUT THIS
MANUAL.
10. Keep this manual and all literature
safeguarded near or on the unit.
WARNING

14
RZ Series Feature String Nomenclature
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
B1
B2
B3
B4
B5
1
2
3A
3B
3C
3D
3E
4A
4B
4C
5A
5B
5C
5D
5E
6A
6B
6C
6D
6E
7
8
9A
9B
9C
9D
RZ
A
-
145
-
D
0
-
3
-
C
A
B
0
A
-
0
0
0
0
0
:
N
0
-
A
A
K
A
Q
-
J
0
0
-
B
F
T
0
M
-
0
0
0
0
0
-
Q
F
-
A
0
A
A
-
0
0
-
M
0
-
C
-
0
0
0
-
8
0
-
D
A
0
B
-
0
0
-
0
0
0
-
A
B
E
Q
0
A
-
E
0
0
0
0
0
-
0
0
0
0
0
D
B
10A
10B
11A
11B
12
13A
13B
13C
14
15
16A
16B
16C
16D
17A
17B
18A
18B
18C
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
MODEL OPTIONS
SERIES AND GENERATION
RZ
MAJOR REVISION
A
UNIT SIZE
Air-Cooled Condenser
EvaporativeCondenser
45 = 45 ton Capacity
51 = 51 ton Capacity
55 = 55 ton Capacity
66 = 66 ton Capacity
65 = 65 ton Capacity
73 = 73 ton Capacity
75 = 75 ton Capacity
79 = 79 ton Capacity
90 = 90 ton Capacity
101 = 101 ton Capacity
105 = 105 ton Capacity
109 = 109 ton Capacity
120 = 120 ton Capacity
124 = 124 ton Capacity
130 = 130 ton Capacity
136 = 136 ton Capacity
140 = 140 ton Capacity
148 = 148 ton Capacity
145 = 145 ton Capacity
161 = 161 ton Capacity
160 = 160 ton Capacity
172 = 172 ton Capacity
180 = 180 ton Capacity
197 = 197 ton Capacity
200 = 200 ton Capacity
221 = 221 ton Capacity
220 = 220 ton Capacity
241 = 241 ton Capacity
240 = 240 ton Capacity
261 = 261 ton Capacity
SERIES
Air-Cooled
A = 45-75 ton units
B = 90-105 ton units
C = 120-140 ton units
D = 145-180 ton units
E = 200-240 ton units
EvaporativeCondenser
A = 51-79 ton units
B = 101-109 ton units
C = 124-148 ton units
D = 161-197 ton units
E = 221-261 ton units
MINOR REVISION
0
VOLTAGE
2 = 230V/3 Φ/60Hz
3 = 460V/3 Φ/60Hz
4 = 575V/3 Φ/60Hz
8 = 208V/3 Φ/60Hz
Model Option A: COOLING/HEAT PUMP
A1: COMPRESSORSTYLE
0 = No Compressor
C = R-410A Variable Speed ScrollCompressor
A2: CONDENSER STYLE
0 = No Condenser
A = MicrochannelAir-Cooled Condenser
H = Evaporative Condenser
A3: INDOOR COIL CONFIGURATION
0 = No Cooling Coil
A = Std Row Std Size Evaporator
B = 6 Row Std Size Evaporator
C = Std RowLarge Size Evaporator
D = 6 RowLarge Size Evaporator
E = 4 Row Chilled WaterCoilStd Size
F = 6 RowChilled WaterCoil Std Size
G = 8 RowChilled WaterCoil Std Size
H = 4 RowChilled WaterCoil Large Size
J = 6 RowChilled Water Coil Large Size
K = 8 RowChilled WaterCoil Large Size
A4: COOLING HEAT EXCHANGER
CONSTRUCTION
0 = Standard
A = Polymer E-Coated Cooling Coil
B = Stainless SteelCooling CoilCasing
D = Stainless SteelCooling CoilCasing +Polymer
E-Coated Cooling Coil
E = PolymerE-Coated Cond.Coil
J = Polymer E-Coated Evap.And Cond.Coil
T = Stainless SteelCooling CoilCasing +PolymerE-
Coated Evap.AndCond.Coil

15
RZ Series Feature String Nomenclature
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
B1
B2
B3
B4
B5
1
2
3A
3B
3C
3D
3E
4A
4B
4C
5A
5B
5C
5D
5E
6A
6B
6C
6D
6E
7
8
9A
9B
9C
9D
RZ
A
-
145
-
D
0
-
3
-
C
A
B
0
A
-
0
0
0
0
0
:
N
0
-
A
A
K
A
Q
-
J
0
0
-
B
F
T
0
M
-
0
0
0
0
0
-
Q
F
-
A
0
A
A
-
0
0
-
M
0
-
C
-
0
0
0
-
8
0
-
D
A
0
B
-
0
0
-
0
0
0
-
A
B
E
Q
0
A
-
E
0
0
0
0
0
-
0
0
0
0
0
D
B
10A
10B
11A
11B
12
13A
13B
13C
14
15
16A
16B
16C
16D
17A
17B
18A
18B
18C
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
A5: COOLING STAGING
0 = No Cooling
A = Full Face Variable Capacity +TandemOn/Off
Refrigeration Systems
F = SingleSerpentine8FPI
G = Half Serpentine8FPI
H = SingleSerpentine 10FPI
J = Half Serpentine 10FPI
K = SingleSerpentine 12FPI
L = Half Serpentine12FPI
Model Option B: HEATING
B1:HEAT TYPE
0 = No Heat
B= Electric Heat
D = NaturalGas Single Rack
E = NaturalGas Double Rack
G = LP Gas SingleRack
H = LP Gas Double Rack
K = Hot WaterCoil
M = SteamDistributingCoil
B2:HEAT CONSTRUCTION
0 = Standard
B = StainlessSteelHeat Exchanger
D = High Altitude StainlessSteelHeat Exchanger
G = PolymerE-Coated Heating Coil
B3:HEAT DESIGNATION
0 = No Heat
1 = Heat 1
2 = Heat 2
3 = Heat 3
4 = Heat 4
5 = Heat 5
6 = Heat 6
7 = Heat 7
8 = Heat 8
B3:HEAT DESIGNATION Continued
A = 1 RowSize A
B = 1 Row Size B
C = 1 Row Size C
D = 1 RowSize D
E = 2 Row Size A
F = 2 RowSize B
G = 2 RowSize C
H = 2 RowSize D
B4:HEAT STAGING
0 = No Heat
A = 1 Stage
B = 2 Stage
C = 3 Stage
D = 4 Stage
E = 5 Stage
F = 6 Stage
G = 7 Stage
H = 8 Stage
V = 10 Stage
J = 12 Stage
K = Modulating Gas Heat Temp Control
L = High TurndownModulating Gas Heat –
TemperatureControl
M = Modulating SCRwith TemperatureControl
N = Modulating SCRwith External 0-10 VDC
R= Single Serpentine10FPI
S = Half Serpentine10FPI
B5:HEAT PUMP AUX HEATING
0 = No Heat Pump

16
RZ Series Feature String Nomenclature
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
B1
B2
B3
B4
B5
1
2
3A
3B
3C
3D
3E
4A
4B
4C
5A
5B
5C
5D
5E
6A
6B
6C
6D
6E
7
8
9A
9B
9C
9D
RZ
A
-
145
-
D
0
-
3
-
C
A
B
0
A
-
0
0
0
0
0
:
N
0
-
A
A
K
A
Q
-
J
0
0
-
B
F
T
0
M
-
0
0
0
0
0
-
Q
F
-
A
0
A
A
-
0
0
-
M
0
-
C
-
0
0
0
-
8
0
-
D
A
0
B
-
0
0
-
0
0
0
-
A
B
E
Q
0
A
-
E
0
0
0
0
0
-
0
0
0
0
0
D
B
10A
10B
11A
11B
12
13A
13B
13C
14
15
16A
16B
16C
16D
17A
17B
18A
18B
18C
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
1: UNIT ORIENTATION
E = Draw ThroughSA Fan,Walk-in Vestibule,Left
SideAccess
F = Draw ThroughSA Fan,Walk-in Vestibule,Right
SideAccess
G = Draw ThroughSA Fan,Non-compressorized,
End ControlPanel,Left Access
H = Draw ThroughSA Fan,Non-compressorized,
End ControlPanel,Right Access
L = Draw ThroughSA Fan,Non-compressorized,
Walk-in Vestibule,Left Access
M = Draw ThroughSA Fan,Non-compressorized,
Walk-in Vestibule,Right Access
N = Blow Through SA Fan,Walk-in Vestibule,Left
SideAccess
P = Blow Through SA Fan,Walk-in Vestibule,Right
SideAccess
Q = Blow Through SA Fan,Non-compressorized,
End ControlPanel,Left Access
R = Blow ThroughSA Fan,Non-compressorized,
End ControlPanel,Right Access
U = Blow Through SA Fan,Non-compressorized,
Walk-in Vestibule,Left Access
V = Blow Through SA,Fan Non-compressorized,
Walk-in Vestibule,Right Access
2: SUPPLY & RETURN LOCATIONS
0 = BottomSupply--BottomReturn
A = BottomSupply--No Return
B= BottomSupply--Left Return
C= BottomSupply--Right Return
D = BottomSupply--End Return
E = Left Supply--No Return
F = Left Supply--BottomReturn
G = Left Supply--Left Return
H = Left Supply--Right Return
J = Left Supply--End Return
K = Right Supply--No Return
L = Right Supply--BottomReturn
M = Right Supply--Left Return
N = Right Supply--Right Return
2: SUPPLY & RETURN LOCATIONS
Continued
P = Right Supply--End Return
Q = Top Supply--No Return
R = Top Supply--BottomReturn
S = Top Supply--Left Return
T = Top Supply--Right Return
U = Top Supply--End Return
Feature 3: SUPPLY FAN OPTIONS
3A: SUPPLYFAN QUANTITY
0 = 1 Fan
A = 2 Fans
B = 3 Fans
C = 4 Fans
D = 5 Fans
E = 6 Fans
F = 7 Fans
G = 8 Fans
H = 9 Fans
J = 10 Fans
K = 11 Fans
L = 12 Fans
3B:SUPPLY FAN CONFIGURATION
0 = No VFDs + Full Width Fan
A = 1 Fan perVFD + Full Width Fan
B = 2 Fans perVFD + Full Width Fan
C = 3 Fans perVFD + Full Width Fan
D = 4 Fans perVFD + Full Width Fan
E = No VFDs + NarrowWidth Fan
F = 1 Fan perVFD + NarrowWidth Fan
G = 2 Fans perVFD + NarrowWidth Fan
H = 3 Fans perVFD + NarrowWidth Fan
J = 4 Fans perVFD+ NarrowWidth Fan
K = Option 0 + Inlet Backdraft Dampers
L = Option A +Inlet Backdraft Dampers
M = Option B + Inlet Backdraft Dampers
N = Option C+ Inlet BackdraftDampers
P = Option D+ Inlet Backdraft Dampers
Q = Option E + Inlet Backdraft Dampers

17
RZ Series Feature String Nomenclature
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
B1
B2
B3
B4
B5
1
2
3A
3B
3C
3D
3E
4A
4B
4C
5A
5B
5C
5D
5E
6A
6B
6C
6D
6E
7
8
9A
9B
9C
9D
RZ
A
-
145
-
D
0
-
3
-
C
A
B
0
A
-
0
0
0
0
0
:
N
0
-
A
A
K
A
Q
-
J
0
0
-
B
F
T
0
M
-
0
0
0
0
0
-
Q
F
-
A
0
A
A
-
0
0
-
M
0
-
C
-
0
0
0
-
8
0
-
D
A
0
B
-
0
0
-
0
0
0
-
A
B
E
Q
0
A
-
E
0
0
0
0
0
-
0
0
0
0
0
D
B
10A
10B
11A
11B
12
13A
13B
13C
14
15
16A
16B
16C
16D
17A
17B
18A
18B
18C
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
3B:SUPPLY FAN CONFIGURATION
Continued
R = Option F+ Inlet Backdraft Dampers
S = Option G+ Inlet Backdraft Dampers
T = Option H+ Inlet Backdraft Dampers
U = Option J+ Inlet Backdraft Dampers
3C: SUPPLYFAN SIZE
G = 27” Direct Drive Backward Curved Plenum
Aluminum
J = 30” Direct Drive Backward Curved Plenum Steel
K = 33” Direct Drive Backward Curved Plenum Steel
L = 36.5” Direct Drive Backward Curved Plenum
Aluminum
M = 42.5” Direct Drive Backward Curved Plenum
Aluminum
N = 18.5” Direct Drive Airfoil Plenum Aluminum
P = 22” Direct Drive Airfoil Plenum Aluminum
Q = 24” Direct Drive Airfoil Plenum Aluminum
R = 27” Direct Drive Airfoil Plenum Aluminum
3D: SUPPLYFAN MOTOR TYPE
0 = High Efficiency Open Motor(1170 nominalrpm)
A = High Efficiency Open Motor(1760nominal
rpm)
K = High Efficiency Totally Enclosed Motor(1170
nominalrpm)
L = High Efficiency Totally EnclosedMotor(1760
nominalrpm)
P = Permanent MagnetACTotally Enclosed Motor
(1760 nominalrpm)
3E: SUPPLY FAN MOTOR SIZE
G = 3 hp
H = 5 hp
J = 7.5 hp
K = 10 hp
L = 15 hp
M = 20 hp
N = 25 hp
P = 30 hp
Q = 40 hp
R = 50 hp
Feature 4: RETURN/OUTSIDE AIR
OPTIONS
4A: OUTSIDE AIR SECTION
0 = 100% Outside Air
A = 100% Outside Airwith Motorized Dampers
B = ManualOutside Air+Return AirOpening
C = Motorized Outside AirDampers +Return Air
Opening
D = 100% Return Air
E = Economizer
G = Econ + PowerExhaust (PlenumFans)
J = Econ + PowerReturn (PlenumFans)
Q = Econ + Energy Recovery +BypassDamper
R = Econ + Energy Recovery +BypassDamper+
PowerReturn (PlenumFans)
4B:ENERGY RECOVERY TYPE
0 = No Energy Recovery
A = Polymer Energy RecoveryWheel
B= PolymerEnergy RecoveryWheel+1% Purge
C = AluminumEnergy RecoveryWheel
D = Aluminum Energy Recovery Wheel+1% Purge

18
RZ Series Feature String Nomenclature
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
B1
B2
B3
B4
B5
1
2
3A
3B
3C
3D
3E
4A
4B
4C
5A
5B
5C
5D
5E
6A
6B
6C
6D
6E
7
8
9A
9B
9C
9D
RZ
A
-
145
-
D
0
-
3
-
C
A
B
0
A
-
0
0
0
0
0
:
N
0
-
A
A
K
A
Q
-
J
0
0
-
B
F
T
0
M
-
0
0
0
0
0
-
Q
F
-
A
0
A
A
-
0
0
-
M
0
-
C
-
0
0
0
-
8
0
-
D
A
0
B
-
0
0
-
0
0
0
-
A
B
E
Q
0
A
-
E
0
0
0
0
0
-
0
0
0
0
0
D
B
10A
10B
11A
11B
12
13A
13B
13C
14
15
16A
16B
16C
16D
17A
17B
18A
18B
18C
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
4C: ENERGY RECOVERY SIZE
0 = No Energy Recovery
A = Small Enthalpy
B= MediumEnthalpy
C= LargeEnthalpy
D = Extra LargeEnthalpy
E = Small Sensible
F = MediumSensible
G = Large Sensible
H = Extra LargeSensible
J = Small Enthalpy +Exhaust Filters
K = MediumEnthalpy +Exhaust Filters
L = Large Enthalpy +Exhaust Filters
M = Extra Large Enthalpy +Exhaust Filters
N = Small Sensible +Exhaust Filters
P = MediumSensible +Exhaust Filters
Q = Large Sensible +Exhaust Filters
R = Extra Large Sensible +Exhaust Filters
Feature 5: RETURN FAN OPTIONS
5A: RETURN FAN QUANTITY
0 = No Return Fan
A = 1 Fan
B = 2 Fans
C = 3 Fans
D = 4 Fans
5B:RETURN FAN CONFIGURATION
0 = No Return Fan
A = No VFDs + FullWidth Fan
B = 1 Fan perVFD + Full Width Fan
C = 2 Fans perVFD + Full Width Fan
D = 3 Fans perVFD + Full Width Fan
E = 4 Fans perVFD + Full Width Fan
F = No VFDs + NarrowWidth Fan
G = 1 Fan perVFD + NarrowWidth Fan
H = 2 Fans perVFD + NarrowWidth Fan
J = 3 Fans perVFD+ NarrowWidth Fan
K = 4 Fans perVFD + NarrowWidth Fan
L = Option A +Inlet Backdraft Dampers
M = Option B + Inlet Backdraft Dampers
5B:RETURN FAN CONFIGURATION
Continued
N = Option C + Inlet Backdraft Dampers
P = Option D+ Inlet Backdraft Dampers
Q = Option E + Inlet Backdraft Dampers
R = Option F+ Inlet Backdraft Dampers
S = Option G+ Inlet Backdraft Dampers
T = Option H+ Inlet Backdraft Dampers
U = Option J+ Inlet Backdraft Dampers
V = Option K+ Inlet Backdraft Dampers
5C: RETURN FAN SIZE
0 = No Return Fan
N = 27” Direct Drive Backward Curved Plenum
Aluminum
Q = 30” Direct Drive Backward Curved Plenum Steel
R = 33” Direct Drive Backward Curved Plenum Steel
S = 36.5” Direct Drive Backward Curved Plenum
Aluminum
T = 42.5” Direct Drive Backward Curved Plenum
Aluminum
U = 18.5" Direct DriveBackwards AirfoilAluminum
V = 22" Direct Drive Backwards AirfoilAluminum
W = 24" Direct Drive Backwards AirfoilAluminum
Y = 27" Direct Drive Backwards AirfoilAluminum
5D: RETURN FAN MOTOR TYPE
0 = No Return Fan
A = High Efficiency Open Motor(1170nominal
rpm)
B = High Efficiency Open Motor(1760 nominal
rpm)
L = High Efficiency Totally EnclosedMotor(1170
nominalrpm)
M = High Efficiency Totally EnclosedMotor(1760
nominalrpm)
P = Permanent MagnetACTotally Enclosed Motor
(1170 nominalrpm)
Q = Permanent MagnetACTotally EnclosedMotor
(1760 nominalrpm)

19
RZ Series Feature String Nomenclature
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
B1
B2
B3
B4
B5
1
2
3A
3B
3C
3D
3E
4A
4B
4C
5A
5B
5C
5D
5E
6A
6B
6C
6D
6E
7
8
9A
9B
9C
9D
RZ
A
-
145
-
D
0
-
3
-
C
A
B
0
A
-
0
0
0
0
0
:
N
0
-
A
A
K
A
Q
-
J
0
0
-
B
F
T
0
M
-
0
0
0
0
0
-
Q
F
-
A
0
A
A
-
0
0
-
M
0
-
C
-
0
0
0
-
8
0
-
D
A
0
B
-
0
0
-
0
0
0
-
A
B
E
Q
0
A
-
E
0
0
0
0
0
-
0
0
0
0
0
D
B
10A
10B
11A
11B
12
13A
13B
13C
14
15
16A
16B
16C
16D
17A
17B
18A
18B
18C
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
5E: RETURN MOTOR SIZE
0 = No Return Fan
H = 3 hp
J = 5 hp
K = 7.5 hp
L = 10 hp
M = 15 hp
N = 20 hp
P = 25 hp
Q = 30 hp
R = 40 hp
Feature 6: EXHAUST FAN OPTIONS
6A: EXHAUST FAN QUANTITY
0 = No Exhaust Fan
A = 1 Fan
B = 2 Fans
6B:EXHAUST FAN CONFIGURATION
0 = No Exhaust Fan
A = No VFDs + FullWidth Fan
B = 1 Fan perVFD + Full Width Fan
C = 2 Fans perVFD + Full Width Fan
F = No VFDs + NarrowWidth Fan
G = 1 Fan perVFD + NarrowWidth Fan
H = 2 Fans perVFD + NarrowWidth Fan
L = Option A +Inlet Backdraft Dampers
M = Option B + Inlet Backdraft Dampers
N = Option C + Inlet Backdraft Dampers
R = Option F+ Inlet Backdraft Dampers
S = Option G+ Inlet Backdraft Dampers
T = Option H+ Inlet Backdraft Dampers
6C: EXHAUST FAN SIZE
0 = No Exhaust Fan
N = 27” Direct Drive Backward Curved Plenum
Aluminum
Q = 30” Direct Drive Backward Curved Plenum Steel
R = 33” Direct Drive Backward Curved Plenum Steel
S = 36.5” Direct Drive Backward Curved Plenum
Aluminum
6C: EXHAUST FAN SIZE Continued
T = 42.5” Direct Drive Backward Curved Plenum
Aluminum
U = 18.5" Direct DriveBackwards AirfoilAluminum
V = 22" Direct Drive Backwards AirfoilAluminum
W = 24" Direct Drive Backwards AirfoilAluminum
Y = 27" Direct Drive Backwards AirfoilAluminum
6D: EXHAUST FAN MOTOR TYPE
0 = No Exhaust Fan
A = High Efficiency Open Motor(1170nominal
rpm)
B = High Efficiency Open Motor(1760 nominal
rpm)
L = High Efficiency Totally EnclosedMotor(1170
nominalrpm)
M = High Efficiency Totally EnclosedMotor(1760
nominalrpm)
P = Permanent MagnetACTotally Enclosed Motor
(1170 nominalrpm)
Q = Permanent MagnetACTotally EnclosedMotor
(1760 nominalrpm)
6E: EXHAUST MOTOR SIZE
0 = No Exhaust Fan
H = 3 hp
J = 5 hp
K = 7.5 hp
L = 10 hp
M = 15 hp
N = 20 hp
P = 25 hp
Q = 30 hp
R = 40 hp

20
RZ Series Feature String Nomenclature
GEN
MJREV
SIZE
SERIES
MNREV
VLT
A1
A2
A3
A4
A5
B1
B2
B3
B4
B5
1
2
3A
3B
3C
3D
3E
4A
4B
4C
5A
5B
5C
5D
5E
6A
6B
6C
6D
6E
7
8
9A
9B
9C
9D
RZ
A
-
145
-
D
0
-
3
-
C
A
B
0
A
-
0
0
0
0
0
:
N
0
-
A
A
K
A
Q
-
J
0
0
-
B
F
T
0
M
-
0
0
0
0
0
-
Q
F
-
A
0
A
A
-
0
0
-
M
0
-
C
-
0
0
0
-
8
0
-
D
A
0
B
-
0
0
-
0
0
0
-
A
B
E
Q
0
A
-
E
0
0
0
0
0
-
0
0
0
0
0
D
B
10A
10B
11A
11B
12
13A
13B
13C
14
15
16A
16B
16C
16D
17A
17B
18A
18B
18C
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
7: O/A CONTROL
0 = Standard(No Actuator)
C = Fully Modulating Actuator-Sensible Limit
D = Fully ModulatingActuator-Enthalpy Limit
E = DDC Actuator
P = Option C+ CO2Override
Q = Option D+ CO2 Override
R = Option E+ CO2 Override
U = 2 Position Actuator
V = Fault Detection andDiagnostics Controller
(FDD) SensibleLimit
W = FDD Enthalpy Limit
Y = Option V+ CO2 Override
Z = Option W +CO2 Override
8: RETURN & EXHAUST OPTIONS
0 = No Return Opening
A = Standard Return Openingwithout EA Dampers
B = Large Return Openingwithout EA Dampers
E = StandardReturn Opening +Motorized EA
Dampers
F = Large Return Opening +Motorized EA Dampers
Feature 9: FILTER OPTIONS
9A: UNIT FILTER TYPE
0 = 2" Pleated MERV8
A = 4" Pleated MERV8
B = 2" Pleated MERV8 + 4" Pleated MERV11
C = 2" Pleated MERV8 + 4" Pleated MERV13
D = 2" Pleated MERV8 + 4" Pleated MERV14
E = 4" Pleated MERV 8 + 4" Pleated MERV11
F = 4" Pleated MERV8 + 4" Pleated MERV13
G = 4" Pleated MERV8 + 4" Pleated MERV14
H = 2" Pleated MERV8 + 12" Cartridge MERV 11
J = 2" Pleated MERV8 + 12" CartridgeMERV 13
K = 2" Pleated MERV8 + 12" Cartridge MERV 14
L = 4" Pleated MERV 8 + 12" Cartridge MERV11
M = 4" Pleated MERV8 + 12" Cartridge MERV 13
N = 4" Pleated MERV8 + 12" Cartridge MERV 14
P = 2" Pleated MERV8 + 30" Bag MERV 13
Q = 2" Pleated MERV8 + 30" Bag MERV 14
9A: UNIT FILTER TYPE Continued
R = 4" Pleated MERV8 + 30" Bag MERV 13
S = 4" Pleated MERV8 + 30" Bag MERV 14
9B:UNIT FILTER BOXSIZE/LOCATION
0 = StandardFilters in Standard Position
A = Standard Filters in Pre-position
B = High Eff Filters Box A in StandardPosition
C = High Eff Filters Box B in Standard Position
D = High Eff Filters Box C in StandardPosition
E = High Eff Filters Box A in Pre-Position
F = High Eff Filters BoxB in Pre-Position
G = High Eff Filters Box C in Pre-Position
H = Dual Angled FilterRacks BoxA in Standard
Position
J = Dual Angled FilterRacks BoxB in Standard
Position
K = Dual Angled FilterRacks BoxA in Pre-Position
L = DualAngled FilterRacks BoxB in Pre-Position
9C: FINAL FILTER TYPE
0 = No Final Filters
A = 12" Cartridge MERV 13--Filter Box A
B = 12" CartridgeMERV 13--Filter Box B
C = 12" CartridgeMERV 13--Filter Box C
D = 12" Cartridge MERV 14--Filter Box A
E = 12" Cartridge MERV14--Filter Box B
F = 12" Cartridge MERV 14--Filter Box C
G = 30" Bag MERV 13--Filter Box A
H = 30" Bag MERV 13--Filter Box B
J = 30" Bag MERV 13--Filter Box C
K = 30" Bag MERV 14--Filter Box A
L = 30" Bag MERV 14--Filter Box B
M = 30" Bag MERV 14--Filter Box C
N = HEPA Frame (No Filter)--Filter Box A
P = HEPA Frame (No Filter)--Filter Box B
Q = 12" 99.97 HEPA--Filter Box A
R= 12" 99.97 HEPA--Filter Box B
S = 4" MERV 8 + 12" 99.97 HEPA--Filter Box A
T = 4" MERV 8 + 12" 99.97 HEPA--Filter Box B