Engineering Manual

VERTICAL-HORIZONTAL INDOOR UNITS
Installation and Best Layout Practices
Drain Piping Specifications
• Drain piping must have downward gradient of at
least 1/50 to 1/100; to prevent reverse flow, slope
should not be straight up and down.
• Do not damage the drain port on the indoor unit
when connecting the field-supplied drain piping.
Drain Hole
Gaps Should Not Be Present
Unit
Drain Piping
(Field Supplied)
Drain Piping Insulation
(Field Supplied)
U-Trap
B
C
A
3/4-inch Connecto
r
Field-Installed U-Trap Specifications
Figure 233:Close up of Drain Piping Connection.
Figure 234:Installing the U-Trap.
To prevent leaks cause by a block in the intake air lter, install a U-Trap.
A ≥ 2-9/16 inches
B ≥ 2C
C ≥ 2 x SP
SP = External Pressure in. WG
Example:
External Pressure= 0.4 in WG
A ≥ 2-9/16 inches
B ≥ 1-7/12 inches
C ≥ 19/24 inches
Drain Access Hole
Air Filter Cover
Main Drain with Suitable Trap. (Field-Supplied
Trap with Sufficient Depth Can Be Used.
Standard Size P-Traps Cannot Be Used.
Supplementary Drain with a
Proper Trap (Field Supplied Kit
Can Be Used)
Figure 235:Vertical Primary and
Secondary Drain Layout.
Figure 236:Horizontal Primary and
Secondary Drain Layout.
Refrigerant Piping Insulation
Field-installed vapor and liquid refrigerant piping lines must
be properly and completely covered in insulation (up to the
indoor unit piping connections) and must comply with federal,
state, and local requirements. Any exposed piping may gener-
ate condensate or will cause burns if touched. Insulation for
this field-installed refrigerant piping must have a minimum
heat resistance of 248°F.
Vertical-horizontal air handling indoor units have been tested
under and meet the requirements of the “KS Conditions.” If
the indoor unit is installed and is operated at an extended
period in a highly humid environment (dew point tempera-
ture >73°F), however, condensate will form. To prevent this
phenomenon, install adiabatic glass wool insulation with a
thickness of 7/16 to 13/16 inches thick. Also, install glass
wool insulation on all indoor unit that are located in the ceiling
plenum.
Drain Piping Insulation
Drain piping must have insulation a minimum of 7/32 inches
thick.
Insulating the Refrigerant and
Drain Piping
Connection for Liquid Piping
Refrigerant Piping
Insulation (Field Supplied)
Connection for Vapor Piping
Insulation Zip Tie (Field Supplied)
Refrigerant Piping Insulation (Field
Supplied)
Figure 237:Close Up of Refrigerant Piping Connection Insulation.
Gaps Should Not be Present
Overlap Piping Insulation
Refrigerant Piping Insulation (Field Supplied)
Insulation Clip (Field Supplied)
Refrigerant Piping Insulation
(Field Supplied)
Figure 238:Insulating the Refrigerant Piping and Refrigerant Piping
Connections.
Due to our policy of continuous product innovation, some specications may change without notication.
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168 | VERTICAL-HORIZONTAL
Multi F and Multi F MAX Indoor Unit Engineering Manual
MULTI
F
MAX
MULTI
F