10                  Specifications subject to change without notice.                             38MAR-04SI
Step 4 - Refrigerant Piping
Table 6 — Piping and Refrigerant Information 
IMPORTANT: Both refrigerant lines must be insulated 
separately. Use refrigeration grade tubing ONLY. No other 
type of tubing may be used. Use of other types of tubing 
will void the manufacturer's warranty.
• The minimum refrigerant line length between the indoor and 
outdoor unit is 10 ft. (3m). 
• When paired with Ductless indoor units, size the line sets based on 
the connection size of the indoor unit unless specified.
• When paired with conventional or multi-family fan coils, size the 
line sets based on the liquid and gas connection size of the outdoor 
unit; a field supplied reducer may be required.
• All outdoor units have an electronic expansion valve to manage the 
refrigerant flow of the fan coil connected.
• Do not open the service valves or remove the protective caps from 
the tubing ends until all connections are made.
• Bend the tubing with bending tools to avoid kinks and flat spots.
• Keep the tubing free of dirt, sand, moisture, and other 
contaminants to avoid damaging the refrigerant system.
• Avoid sags in the suction line to prevent the formation of oil traps. 
• Insulate each tube with a minimum 3/8-in. (10 mm) wall thermal 
pipe insulation. Inserting the tubing into the insulation before 
making the connections will save time and improve installation 
quality.
SIZE
12K
(115V)
9K 
(208/230V)
12 
(208/230V)
18K 
(208/230V)
24K 
(208/230V)
30K 
(208/230V)
36K 
(208/230V)
Piping
Min. Piping Length Ft (m) 10 (3) 10 (3) 10 (3) 10 (3) 10 (3) 10 (3) 10 (3)
Standard 
Piping Length
Ft (m) 25 (7.5) 25 (7.5) 25 (7.5) 25 (7.5) 25 (7.5) 25 (7.5) 25 (7.5)
Max. Outdoor indoor 
height difference
Ft (m) 32 (10) 32 (10) 32 (10) 65 (20) 65 (20) 82 (25) 82 (25)
Max. Piping Length 
with no additional 
refrigerant charge
Ft (m) 26 (8) 26 (8) 26 (8) 26 (8) 26 (8) 26 (8) 26 (8)
Max. Piping Length Ft (m) 82 (25) 82 (25) 82 (25) 98 (30) 164 (50) 164 (50) 164 (50)
Additional refrigerant charge 
(between Standard – Max 
piping length)
Oz/ft (g/m) 0.16 (15) 0.16 (15) 0.16 (15) 0.16 (15) 0.32 (30) 0.32 (30) 0.32 (30)
Gas Pipe
in 1/2 3/8 1/2 1/2 5/8 5/8 5/8
(mm) 12.7 9.52 12.7 12.7 16 16 16
Liquid Pipe
in 1/4 1/4 1/4 1/4 3/8 3/8 3/8
(mm) 6.35 6.35 6.35 6.35 9.52 9.52 9.52
Refrigerant
Refrigerant Type - R410A R410A R410A R410A R410A R410A R410A
Charge Amount
Lbs
(kg)
2.76 (125) 3.31 (1.5) 3.31 (1.5) 4.30 (1.95) 5.73 (2.60) 6.06 (2.75) 7.50 (3.40)
All field piping must be completed by a licensed technician and 
must comply with the local and national regulations.
When the system is installed in a small room, measures must be 
taken to prevent the refrigerant concentration in the room from 
exceeding the safety limit in the event of refrigerant leakage. If the 
refrigerant leaks and its concentration exceeds its proper limit, 
hazards due to lack of oxygen may result.
When installing the refrigeration system, ensure that air, dust, 
moisture or foreign substances do not enter the refrigerant circuit. 
Contamination in the system may cause poor operating capacity, 
high pressure in the refrigeration cycle, explosion or injury.
Ventilate the area immediately if there is refrigerant leakage 
during the installation.
Leaked refrigerant gas is hazardous. Ensure there is no refrigerant 
leakage after completing the installation work.
WARNING
DO NOT install the connecting pipe until both the indoor and 
outdoor units have been installed.
Insulate both the gas and liquid piping to prevent condensation.
CAUTION