Lennox VRB096, VRB168, VRB216, VRB192, VRB240 Installation & Operation Instructions

INSTALLATION/OPERATION

VRF

INSTRUCTIONS

©2018 Lennox Industries Inc. Dallas, Texas, USA

THIS MANUAL MUST BE LEFT WITH THE

OWNER FOR FUTURE REFERENCE

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.

!

WARNING

Improper installation, adjustment, alteration,
service or maintenance can cause property
damage, personal injury or loss of life.
Installation and service must be performed
by a licensed professional HVAC installer (or
equivalent) or service agency.
Failure to follow safety warnings and these
instruc tions exactly could result in property
damage, dan gerous operation, serious injury,
or death.
Any additions, changes, or conversions
required in order for the appliance to
satisfactorily meet the ap plication needs must
be made by a licensed profes sional HVAC

installer (or equivalent) using factory-specied

parts.
Do not use this system if any part has been

under water. A ood-damaged appliance is

extremely dan gerous. Immediately call a
licensed professional HVAC service technician
(or equivalent) to inspect the system and to
replace all controls and electrical parts that
have been wet, or to replace the system, if
deemed necessary.

VRB Heat Recovery

VRF SYSTEMS
OUTDOOR UNITS
507885-03
05/2019

!

WARNING

Do not change the settings of any protection
devices installed in the outdoor unit. If the
pressure switch, thermal switch, or other
protection device is shorted or forcibly

operated, re or explosion may occur.
Do not use parts other than those specied by
Lennox or re and/or explosion may occur.

CAUTION

As with any mechanical equipment, contact
with sharp sheet metal edges can result in
personal injury. Take care while handling this
equipment and wear gloves and protective
clothing.

IMPORTANT

The Clean Air Act of 1990 bans the intentional
venting of refrigerant (CFC’s and HCFC’s) as of
July 1, 1992. Approved methods of recovery,
recycling or reclaiming must be followed. Fines

and/or incarceration may be levied for non-

compliance.
These units must be installed as part of a

matched system as specied in the Product
Specications (EHB) bulletin.

General

The VRB heat recovery outdoor units are matched
with up to 64 indoor units per system to create a VRF

(variable refrigerant ow) system that uses HFC-

410A refrigerant.

Refer to the Product Specication bulletin (EHB)

for the proper use of these heat recovery units with

matching indoor units, mode selection boxes, branch
pipes, line sets and controls.

Shipping and Packing List

Check the components for shipping damage. If you
nd any damage, immediately contact the last car­rier. Package 1 of 1 contains the following:
1 - Assembled VRB heat recovery outdoor unit
1 - Outdoor unit installation instruction
1 - Piping accessory package

1

Safety Requirements

!

WARNING

ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD.
Do not touch the unit or the controller if your hands are wet.

Do not operate appliances with an open ame near the unit.
Do not replace a fuse with a fuse of a di󰀨erent rating. Do not attempt to bypass a fuse.

Do not insert your hands, tools or any other item into the air intake or air outlet at either the indoor or outdoor
unit.
Do not allow children to operate the system.

Model Number Identication

V R B 072 H 4 M -3 Y

Brand/Family

V = Variable Refrigerant Flow (VRF)

Unit Type

R = Heat Recovery Outdoor Unit

Major Design Sequence

B = 2nd Generation

Nominal Cooling Capacity - Tons
072 = 6 Tons

096 = 8 Tons
120 = 10 Tons
144 = 12 Tons
168 = 14 Tons
192 = 16 Tons
216 = 18 Tons
240 = 20 Tons
264 = 22 Tons

288 = 24 Tons
312 = 26 Tons
336 = 28 Tons
360 = 30 Tons
384 = 32 Tons
408 = 34 Tons
432 = 36 Tons
456 = 38 Tons
480 = 40 Tons
504 = 41 Tons

Voltage

Y = 208/230V-3 phase-60hz
G = 460V-3 phase-60hz

Controls Protocol

3 = Phase 3

Refrigerant Circuits

M = Multiple Circuits

Refrigerant Type

4 = R-410A

Cooling E󰀩ciency

H = High E󰀩ciency

NOTE - Lennox VRF and Lennox Mini-Split products are similar in appearance to each other. Refer to the unit’s model
number to determine if the unit is a VRF (V) or Mini-Split (M) unit. It is not possible to mix the two types of equipment
on any system.

System Piping

CAUTION

VRF system piping is customized for each installation. The Lennox VRF Selection Software (LVSS) piping report is an

engineered design that must be followed. The piping diagram or diagrams included within the LVSS report have been

prepared based on the information provided to the Lennox VRF applications department.
When the indicated lengths change from the gures stated within the report, it is imperative that prior to the commencement

of the refrigerant pipe work installation, Lennox VRF applications department are informed of these proposed changes.
Upon receipt of this new information the Lennox VRF applications department will conrm any changes that may be

applicable to this installation. If changes are required, a new piping diagram will be produced and will supersede all other

previously provided documents.

Failure to provide this information regarding changes to the original design may lead to insu󰀩cient capacity, equipment
failure, warranty being made void and the refusal to commission the system.

2

Unit Dimensions - inches (mm)

CORNER WEIGHTS CENTER OF GRAVITY

Model No. AA BB CC DD EE FF

lbs. kg lbs. kg lbs. kg lbs. kg in. mm in. mm

072, 096, 120 121 55 203 92 211 96 251 114 27-3/4 705 12-1/4 311

AA

DD

EE

TOP VIEW

52-3/4 (1340)

BB

FF

CC

CENTER OF
GRAVITY

64-3/8
(1635)

BACK VIEW

LAG BOLT DESIGNATION

(BOTH SIDES)

(TO ACCESS LAG BOLT)

PARALLEL MODULE

PIPING KNOCKOUT

FORKLIFT SLOT

REFRIGERANT LINE PATH

FRONT VIEW

(BOTH SIDES)

11-3/4 (298)

53-1/8 (1349)

BASE PAN VIEW

3

LIFTING HOLES

(BOTH SIDES)

(FOR RIGGING)

6-1/4 (159)

18-7/8 (479)

29-7/8 (759)

31-1/2 (800)

SIDE VIEW

29-1/2

(749)

4-1/8 (105)

Unit Dimensions - inches (mm)

CORNER WEIGHTS CENTER OF GRAVITY

Model No. AA BB CC DD EE FF

lbs. kg lbs. kg lbs. kg lbs. kg in. mm in. mm

144, 168, 192 172 78 264 120 330 150 321 146 37-3/4 953 12 305

AA

DD

EE

TOP VIEW

68-1/2 (1740)

BB

FF

CC

CENTER OF
GRAVITY

72 (1829)

BACK VIEW

LAG BOLT DESIGNATION

(BOTH SIDES)

(TO ACCESS LAG BOLT)

PARALLEL MODULE

PIPING KNOCKOUT

REFRIGERANT LINE PATH

FRONT VIEW

FORKLIFT SLOT

(BOTH SIDES)

11-3/8 (289)

68-1/2 (1740)

BASE PAN VIEW

4

6-1/4 (159)

18-7/8 (479)

30 (762)

32-5/8 (829)

SIDE VIEW

29-3/4 (756)

4-1/8 (105)

Dimensions - Piping Details - inches (mm)

Internal valve layouts are the same in both heat

recovery and heat pump units, it is their function that
is di󰀨erent. Pay close attention when making nal

piping connections.

Low pressure gas valve

High pressure
gas balance valve

Low pressure gas pipe
(1-1/8 in. diameter 072-120 sizes)
(1-3/8 in. diameter 144-192 sizes)

High pressure
gas balance pipe

(3/4 in. diameter)

6-1/4 (159)

5-5/8 (143)

Heat Recovery internal valve layouts are described
below. See the Heat Pump installation manual for

heat pump internal valve information.

High pressure gas valve

Liquid side valve

Liquid side valve

Oil balance valve

Liquid side pipe
(5/8 in. diameter 072-120 sizes)
(3/4 in. diameter 144-192 sizes)

High pressure gas pipe
(1-1/8 in. diameter 072-120 sizes)
(1-3/8 in. diameter 144-192 sizes)

Oil balance pipe

(1/4 in. diameter)

5

Outdoor Unit Placement Considerations

!

WARNING

Use the provided and specied components

when installing equipment. Failure to do so may
result in unit falling, water leaking or electrical
shocks, caus ing personal injury or equipment
or property dam age.
Check stability of unit support. If sup port is
not capable of carrying weight of the unit, unit
may fall causing personal injury or equipment
damage.
Safely dispose of packing materials, which
include nails, wood and other sharp objects,
as well as plastic wrapping. Children playing
with plastic wrap or bags risk the danger of

su󰀨ocation.

IMPORTANT!

Exhaust vents from dryers, water heaters and
furnaces should be directed away from the
outdoor unit. Prolonged exposure to exhaust
gases and the chemicals contained within
them may cause condensation to form on the
steel cabinet and other metal components of
the outdoor unit. This will diminish unit perfor­mance and longevity.

In addition to clearances, the following items should

be considered when setting the outdoor unit:

• 2007 EPA Noise Policy. Observe local code
adoptions/enforcement as consideration should
be used when selecting an outdoor unit’s perma­nent placement. Sound data for each unit can be

found in the Product Specications Document.

• Glass has a very high level of sound transmis­sion. When possible, do not install the unit direct­ly outside a window.

• Avoid installing the unit in areas exposed to ex-

treme voltage variations (such as factories).

• Install unit level.

• Allow su󰀩cient space around unit for proper op­eration and maintenance.

• Install the outdoor unit a minimum of 3 ft. (1 m)

away from any antenna, power cord (line), radio,
telephone, security system, or intercom. Electri-

cal interference and radio frequencies from any

of these sources may a󰀨ect operation.

• Outdoor unit shall maintain a minimum distance

of 10 ft. (3 m) from dryer exhaust vents.

• Outdoor unit shall maintain a minimum distance
of 10 ft. (3 m) from Type 1 kitchen exhaust out­lets.

• Coating outdoor coils is recommended in appli­cations installed in coastal regions less than 30

miles (48 kilometers) inland.

6

SINGLE ROW

Lifting the Unit

• Do not hold the air inlet grille while lifting the unit.
This could result in damage to the cabinet.

39 (991)

• Do not touch the fan blades with your hands or
other objects while lifting the unit.

Air Flow

Air Flow

31 (800)

39 (991)

39 (991)

Front Front

4 to 20 (102 to 508)

TWO ROWS

39 (991)

39 (991)

Front Front

39 (991)

Front Front

39 (991)

4 to 20 (102 to 508)

THREE OR MORE ROWS

FrontRear

Air Flow

Air Flow

31 (800)

39 (991)

39 (991)

39 (991)

39 (991)

39 (991)

Front Front

Air Flow

Front Front

Air Flow

31 (800)

Front Front

4 to 20 (102 to 508)

Figure 1. Installation Clearances - inches (mm)

7

NOTICE

Drawings in this manual are for illustrative purposes
and should not be used as a template for fabricating
eld-supplied accessories or apparatuses. Consider
the environment in which this unit is being installed and
make necessary adjustments to ensure safe operation.
Local codes prevail.

Clearances from Obstructions

• Allow adequate air ow clearance on all sides of

the unit. See Figure 1 and this section.

• Allow at least 39 in. (991 mm) clearance in front

of the unit for maintenance and service access.
The outdoor unit service access is via hinged
service doors that swing open in front of the unit.
Figure 2.

>39”

(991 mm)

Rear Side

Front Side

>32”

(813 mm)

Front SideRear Side

Figure 3. Perimeter Obstructions

• Allow at least 120 in. (3048 mm) clearance above
the unit. If an obstruction above the unit does not

allow for adequate clearance, a eld-supplied

discharge duct is required. The discharge duct
should be installed in such a way as to ensure
that discharge air goes beyond the obstruction
and does not cause recirculation of discharge air.
Ensure that the static capabilities of the outdoor

unit are not exceeded. Figure 4.

Figure 2. Maintenance & Service Clearance

• Perimeter obstructions that are 32 in. (813

mm) taller than the top of the outdoor unit
require a eld supplied air discharge duct

to avoid recirculation of discharge air.
The discharge duct should be installed to at
least the height of the surrounding obstructions

(for ex. walls) to ensure that discharge air

goes over the height of the obstruction.
Ensure that the static capabilities of the outdoor

unit are not exceeded. Figure 3.

!

CAUTION

In order to avoid injury, take proper precaution
when lifting heavy objects.
Take care when using a sling to lift the unit for
in stallation. The unit center of gravity is not at
its physical center.

>120”

(3048 mm)

Front Side Rear Side

Figure 4. Obstructions Above the Unit

8

Cold Climate Considerations

Select a location where high winds and snow will not

a󰀨ect the unit. In areas where typical ambient tem­peratures are below 50°F (10°C), the following pre-

cautions should be observed.

• Locate unit away from overhanging roof lines

which would allow water or ice to drop on, or in
front of, coil or into unit.

Eaves

Icicle

Wrong Installation

• Install snow guards to prevent snow fall from en­tering air inlet and outlet.

Correct Installation

Snow
Guard
Kit

Snow level

Wrong Installation

Snow
Guard
Kit

RearFrontRearFront

Snow level

RearFront

Figure 5. Do Not Locate Under Roof Overhang

• The unit base should be elevated above the

depth of average snows plus 12 in. (305 mm). In
heavy snow areas, do not locate the unit where

drifting will occur.

Correct Installation

RearFront

Snow Drifts

NOTE - Snow guards are recommended on both sides
and rear of the unit as shown in this example.

Figure 7. Elevate Above Average Snow Level

& Protect Coil

• If necessary, install the unit on a raised base
made of angle iron and that allows snow and
wind to pass through

Correct Installation

RearFront

Wrong Installation

Defrost

Water

RearFront

Defrost

Water

Wind

RearFront

Snowdrift

Wrong Installation

Figure 6. Do Not Locate Where Drifting Will Occur

Defrost

Water

Figure 8. Secure Unit to

Weather Resistant Support

IMPORTANT

These illustrations are examples of possible snow

protection options. They should not be used as a
template for fabricating the snow protection apparatuses.
Consider the environment in which this unit is being
installed and make necessary adjustments to ensure
safe operation.

9

• When installed in areas where low ambient tem-

peratures exist, locate unit so winter prevailing

winds do not blow directly on to the outdoor unit.

Wind

Rear Front

Wind

Wind

Inlet

Outlet

RearFront

Outlet

llation

Wrong Installation

Wrong Installation

Air Discharge Duct

• Before installing the air duct, remove the two fan
guards from the top of the unit.

• Duct each outdoor unit separately. Do not use
a combined plenum as this may result in air not
being discharged directly to the outside.

• Discharge air duct shall be constructed of steel
and installed in a manner which prevents sagging
and or collapsing.

• Only one bend is allowed in the air duct.

• Duct louvers will reduce air volume, cooling and

heating capacity and e󰀩ciency. Louvers are not
recommended; if they are required by the job,

the louver angle should be no larger than 15°.

• It may be necessary to install a exible connector
between the unit and the duct to reduce vibration
noise.

Table 1. Static Pressure Settings

Static Pressure Description

0 WG (0 Pa) Default

0-0.08 WG (0-20

Pa)

Above 0.08 WG

(20 Pa)

Remove fan guard, < 10 ft. (3 m)

duct length

Contact Lennox VRF Applications

Support

RearFront

Correct Installation

Figure 9. Protect Unit from Prevailing Winds

NOTE - Use dip switch S4 to change outdoor
unit static pressure settings.

10

Support

C

Radius

E

A

Radius

3-1/2 in.

(89 mm)

≤ 15°

4 in. (102 mm)

Air Outlet Louver

072, 096, 120 -- 50-3/4 in. (1289 mm)

144, 168, 192 -- 65 in. (1651 mm)

B

F

8 × ST3.9

self-threading screws

Fan guards

(remove

first)

!

Contact the Lennox VRF

applications department for
assistance with ducting applications

that di󰀨er from these images.

Figure 10. Air Discharge Duct

072, 096, 120

A A ≥ 12 in.(305 mm)

B B ≥ 10 in. (254 mm)

C C ≤ 118-1/8 in. (3000 mm)

D D ≥ 24 in. (610 mm)

E E = A + 24 in. (610 mm)

F 24 in. (610 mm)

(Front or Rear Connection)

11

144, 168, 192

A A ≥ 12 in.(305 mm)

B B ≥ 10 in. (254 mm)

C C ≤ 118-1/8 in. (3000 mm)

D D ≥ 28-3/8 in. (721 mm)

E E = A + 24 in. (610 mm)

F 28-3/8 in. (721 mm)

Discharge Duct Pressure Curves

VRB072

VRB120

6-ton Air Volume (CFM)

15000

14000

13000

12000

11000

10000

9000

8000

7000

6000

0 0.04 0.08 0.1 2 0.16 0.2 0.24 0.2 8 0.32

Static Pressure (in.wg.) Air Volume (CFM)

0 13934

0.04 13320

0.08 12667

0.12 12010

0.16 11236

0.2 10163

0.24 8940

0.28 7902

0.32 7094

10-ton Air Volume (CFM)

18000

16000

14000

12000

10000

8000

6000

0 0.04 0.08 0.12 0.16 0.2 0.24 0.28 0.32

Static Pressure (in.wg.) Air Volume (CFM)

0 15667

0.04 15090

0.08 14508

0.12 13907

0.16 13261

0.2 12467

0.24 11554

0.28 10655

0.32 9709

VRB096

8-ton Air Volume (CFM)

16000

15000

14000

13000

12000

11000

10000

9000

8000

7000

6000

0 0.04 0.08 0.12 0.16 0.2 0.24 0.28 0.32

Static Pressure (in.wg.) Air Volume (CFM)

0 14800

0.04 14205

0.08 13587

0.12 12958

0.16 12248

0.2 11315

0.24 10247

0.28 9279

0.32 8402

VRB144, 168, & 192

12~16-ton Air Volume (CFM)

25000

24000

23000

22000

21000

20000

19000

18000

17000

0 0.04 0.08 0.12 0.16 0.2 0.24 0.28 0.32

Static Pressure (in.wg.) Air Volume (CFM)

0 24544

0.04 24079

0.08 23559

0.12 22986

0.16 22360

0.2 21679

0.24 20945

0.28 20157

0.32 19315

12

Main/Sub Outdoor Unit Placement

• A VRF system consisting of more than two
outdoor units must be placed in order from the

largest to the smallest capacity. See gure 8.

• The largest capacity outdoor unit must be
installed closest to the main pipe leading into the
building. See Figure 11.

• The largest capacity outdoor unit address is the

main unit, while the others are the sub units. See

Figure 11.

• All of the outdoor units manifolded together
should be installed at the same elevation.

Main unit
placed
closest to
main pipe
leading into
building

Main piping

to building

16-ton

Outdoor Unit

Branch Pipe Kits

14-ton 10-ton

NOTE - All of the outdoor units manifolded
together should be installed at the same elevation.

• If the unit coil cannot be installed away from

prevailing winter winds, a wind barrier should

be constructed. Size barrier at least the same
height and width as outdoor unit. Install barrier

12 inches (305 mm) minimum from the sides of

the unit in the direction of prevailing winds.

IMPORTANT!

Roof Damage!
This system contains both refrigerant and

oil. Some rubber roong material may absorb

oil. This will cause the rubber to swell when
it comes into contact with oil. The rubber will
then bubble and could cause leaks. Protect the
roof surface to avoid expo sure to refrigerant
and oil during service and instal lation. Failure
to follow this notice could result in damage to
roof surface.

Securing Outdoor Unit to Slab or Frame

Use lag bolts (min. 3/8 in.) at all four corners to
secure the unit to the eld-provided slab or frame.

Isolation material can be used to control vibration or

sound transmission. Lag bolts must extend through

material to the slab or frame. See Figure 12.

Figure 11. Main/Sub Unit Placement

(40-Ton System Example)

Installation

Slab or Roof Mounting

Install the unit a minimum of 8 inches (203 mm)

above the roof or ground surface to avoid ice build­up around the unit. Locate the unit above a load­bearing area of the roof that can adequately support
the unit. Consult local codes for rooftop applications.

• Use a eld supplied slab or suitably sized
steelwork to construct a base for locating
the condensing unit. All supporting work
should be veried by a qualied engineer.

NOTE - Prefabricated light duty equipment pads
are NOT suitable for use.

• Support the unit across the front and back of the
unit.

Use lag

bolts (4) to

secure unit
to slab or
approved frame
at each corner

8 in.
(203 mm)

Figure 12. Secure Outdoor Unit

to Approved Structure

13

Refrigerant Piping Connections

!

WARNING

Refrigerant leaks are unlikely; however, if a
refriger ant leak occurs, open a door or windows

to dilute the refrigerant in the room. Turn o󰀨 the

unit and all other appliances that may cause
a spark. Call a li censed professional HVAC
technician (or equiva lent) to repair the leak.
Use only R-410A refrigerant to charge this
system. Use of other refrigerant or gas will
damage the equipment.
Do not allow air or other contaminants to
enter sys tem during installation of refrigerant
piping. Con taminants will result in lower
system capacity and abnormally high operating
pressures and may res ult in system failure or
explosion.
Insulate all refrigerant piping.
Refrigerant pipes may be very hot during unit
opera tion. Do not allow contact between wiring
and bare copper pipes.
After refrigerant piping connections have been
completed, check the system for leaks per
commis sioning instructions.

• Both liquid and gas (vapor) lines must be indi-

vidually insulated.

• Field piping consists of three HVAC/R eld-pro-

vided copper refrigerant lines connected to the
outdoor unit. These lines carry the liquid and va­por refrigerant to and from the mode selection

box(es).

• Refrigerant piping and wiring connections can be
brought into the outdoor unit through openings

provided in the front, side(s), or underside (rec­ommended) of the unit.

• Refrigerant piping must be connected using

mode selection boxes and individual branch pipe

kits. Six mode selection boxes are available in

varying sizes to accommodate connection of one
to 41 indoor units.

• The following restrictions apply to each VRB sys­tem:

• Total refrigerant pipe length 3280 ft. (1000 m)

• Longest pipe length actual) 574 ft. (175 m)

• Level di󰀨erence between indoor units 98 ft.

(30 m)

• Piping length from the rst branch pipe to the

farthest indoor unit 132/295 ft. (40/90 m)

• For each branch pipe, allow 20” (508 mm) of
equivalent length.

!

Contact the Lennox VRF applications department

for assistance.

• When the outdoor unit is installed 164 feet (50

m) or more above the indoor units, install an oil
return trap every 33 feet (10 m) in the main low

pressure gas pipe. See Figure 13 for trap speci-

cations.

≥1ft

≥1ft

Figure 13. Oil Return Trap

• When the outdoor unit is 132 feet (40 m) or more
below the indoor units, increase the diameter of

the liquid line pipe from the outdoor unit to the

rst branch pipe by one size. ! Contact the Len­nox VRF applications department for assistance.

• To extend the length from the rst branch pipe to
the farthest indoor unit beyond 132 ft. (40 m) and
up to 295 ft. (90 m), the following three conditions

must be met.

1. Increase diameter of the main pipe between

the rst and the last branch pipes. If the diam­eter of the pipe is the same as the main outdoor

pipe, then it does not need to be increased.
Ex: If 132 ft.<L1+L7+L9+L10 ≤ 295 ft., in-

crease the diameter of all the pipes by one
size.

2. The length from the indoor unit to the nearest

branch pipe must be 132 ft. (40 m) or less.
Ex: a,b,c,d,e,f,g,h,i,j,k,l,m ≤ 132 ft.

3. The di󰀨erence between [the distance from

the outdoor unit to the farthest indoor

unit] and [the distance from the outdoor
unit to the nearest indoor unit] is ≤132 ft.
Ex:(L1+L7+L9+L11+11+j+k+n)

-(L1+L7+L8+p)
≤ 132 ft.

!

Contact the Lennox VRF applications department

for assistance.

IMPORTANT!

The compressor in this unit contains PVE oil
(Polyvinylether). PVE oil is formulated for hy-

drouorocarbon (HFC) refrigerants, such as R-

410a, which this system contains. While it may
have some miscibility properties with mineral
based oil and POE oil (Polyolester), you should
not mix PVE oil with any other type of refriger­ant oil.

14

Maximum Permitted Refrigerant Pipe Length and Maximum Height Difference

OUTDOOR UNITS
(one or more outdoor units)

NOTE - Capacities are shown in parenthesis

a

b

c

MS1

L1

A

L2

L3

B

L4

C

L6

L5

MS3

MS2

INDOOR UNITS

N1

(024)

N2

(024)

d

e

The first line Branch Pipe

N4

(009)

N3

(048)

Maximum equivalent single piping length - 656 ft.(200 m)

L7

Maximum piping length from the first Branch Pipe
joint to the farthest indoor unit - 295 ft. (90 m)

LEGEND

Branch Pipe

Mode Selection
Box (MS)

Maximum level difference between

Indoor Unit

L8

D

L9

L10

E

L11

F

MS6

Indoor Unit and Outdoor Unit - 361 ft. (110 m)

MS7

f

MS4

L12

MS5

L13

Maximum piping length from MS Device
to downstream indoor unit - 131 ft. (40 m)

k

j

r

N13
(018)

q

N12

(048)

p

N11

(048)

l

N5

(048)

g

i

m n

N8

(009)

h

N9

(018)

N6

(024)

N7

(024)

N10
(018)

Maximum level difference between indoor units - 98 ft. (30 m)

Piping Length Permitted value Piping

Total piping length

Single piping length

Piping length from the rst branch joint to the

Piping

Length

farthest indoor unit

Actual length 574 ft. (175 m)
Equivalent length2 656 ft. (200 m)

Piping length from Mode Selection Box (MS) to

the downstream indoor unit of itself

Level di󰀨erence between

indoor unit and outdoor unit

Level

Level di󰀨erence between indoor units 98 ft. (30 m) - - -

Di󰀨erence

NOTES:

The rst branch in all systems must be centrally located between all Mode Selection (MS) Boxes.

1

When counting the total piping length, double the actual length of the distribution pipes between rst Branch Pipe joint and Mode Selection Box (MS): Installation.

Total piping length = L1+(L2+L3+L4+L5+L6+L7+L8+L9+L10+L11+L12+L13)×2+a+b+c+d+e+f+g+h+i+j+k+l+m+n+p+q+r ≤ 3280 ft.(1000 m).

2

Each Branch Pipe or bend is equivalent to 20 in. (508 mm).

3

The maximum allowable piping length from the rst Branch Pipe joint to the farthest indoor unit must be ≤ 132 ft. (40 m), but if the following conditions are met, the

maximum allowable length can be extended to 295 ft. (90 m):

• The piping length from each indoor unit to the nearest Branch Pipe joint or direct connected Mode Selection Box (MS) must be less than 132 ft. (40m) (b to r).

• The di󰀨erence in length between the outdoor unit to the farthest indoor unit, and the outdoor unit to the nearest indoor unit is ≤ 132 ft. (40 m).
Example: The farthest indoor unit is N10, The nearest indoor unit is N11 (L1+L7+L9+L11+j+k+n) minus (L1+L7+L8+p) ≤ 132 ft. (40 m).

• Increase the distribution pipe diameter between the rst Branch Pipe and Mode Selection Box (MS) L2-L13. If the pipe diameter is the same as the main outdoor pipe,

it does not need to be increased.

Pipe Size Allowable Increase Diameters (in.):

3/8 to 1/2 1/2 to 5/8 5/8 to 3/4 3/4 to 7/8 7/8 to 1-1/8 1-1/8 to 1-3/8 1-3/8 to 1-5/8 1-5/8 to 2-1/8

4

When the outdoor unit is higher than indoor units and the level di󰀨erence is over 164 ft. (50 m), it is required to set an oil return bend every 33 ft.(10 m) in the gas pipe of

the main pipe. Refer to Installation Instructions for additional details.

5

When the outdoor unit is lower than indoor units and the level di󰀨erence is more than 132 ft.(40 m), the main liquid pipe pipe need to increase by one size.

Outdoor unit up4 360 ft. (110 m) - - -

Outdoor unit down

1

3280 ft. (1000 m)

3

132/295 ft. (40/90 m) L7+L9+L11+j+k+n

132 ft. (40 m) j+k+n

5

230 ft. (70 m) - - -

L1+(L2+L3+L4+L5+L6+L7+L8+L9+L10+L11+L12+L1

3)×2+a+b+c+d+e+f+g+h+i+j+k+l+m+n+p+q+r

L1+L7+L9+L11+j+k+n

15