For optimal unit operation, a maximum total equivalent length (linear feet of horizontal pipe + linear feet of vertical pipe + equivalent lengths of all fittings) of 150 feet is permissible. Long line sets of up to 200 linear feet/250 total equivalent feet are permissible on 3-phase systems. The allowed vertical component varies depending on system configuration.

Total allowable linear, vertical distances for remote condensers/condensing units vary by unit configuration.

Compressor Location	Relative Position	Maximum Vertical Piping
Air Handling Section	Condenser above Air Handling	100 linear feet
	Condenser below Air Handling	20 linear feet
Condensing Section	Condensing Unit above Air Handling	50 linear feet
	Condensing Unit below Air Handling	50 linear feet

For heat pump applications: condensing and evaporating sections flip functionality during heat pump operation. Select the most restrictive option when determining your maximum vertical component. All heat pumps are subject to the 150 total equivalent feet maximum run.

For units with the compressor located in the condensing section AND hot gas reheat: the maximum total linear distance between the condensing section and air handling section is 40 linear feet.

Installations in excess of these limitations may result in reduced system performance, refrigerant pressure problems, oil return issues, and may void your compressor warranty.

AboveAir Units are customizable for a variety of configurations. Split configurations are summarized as follows:

Compressor Location	Lines Required
Condensing Section	Suction and Liquid per circuit
Air Handling Section	Discharge and Liquid per circuit
Condensing Section (with remote hot gas reheat)	Suction and Liquid per circuit. Hot gas reheat supply & return sized as Discharge.

Use Type L or K copper refrigerant grade piping for all refrigerant lines. Securely mount all refrigerant lines to the building structure with brackets intended for use with refrigerant/copper piping. Where refrigerant lines pass through walls or floors, provide a sleeve to prevent the line from rubbing. Route piping through chases, ceiling plenums, wall cavities, conduit, or similar protected areas to minimize the possibility of damage to the piping.

Slope all vapor refrigerant piping in the direction of flow at 1/4” per ten feet: slope the hot gas discharge line towards the condenser and the suction line towards the compressor. Slope hot gas reheat supply towards the air handling section and return towards the condensing unit. Liquid lines may be installed without slope.

Piping should be installed without sags or bends. Use proper transition fittings to transition from evaporator and condenser stub out sizes to the refrigerant line sizes calculated herein.

Braze all piping connections with a high quality, high temperature brazing compound of 15% silver suitable for use with the refrigerant used in your unit (typically R-410A) and in accordance with all local, national and ASHRAE code requirements. Take care to avoid introducing debris to the piping system. Run dry nitrogen through the piping continuously during the brazing process to minimize contamination and ensure joint quality.

Pipe insulation materials should be provided as required by the project documents and local codes. Piping should be insulated in accordance with the following:

Discharge Line (and Hot Gas Reheat Lines)

Insulation with 1/2" minimum thickness is required on all indoor piping. Insulation is not required on outdoor piping, but may be desired where low ambient temperatures may cause refrigerant to condense prematurely.

Liquid Line

Insulation is generally not required. If the liquid line passes through a space warmer than the refrigerant (110-115°F), then 1/2" insulation is recommended. Insulation is also recommended where these temperatures may pose a safety issue to space occupants.

Suction Line

Insulation with 1/2" minimum thickness is required on all field piping.

Traps should be provided as follows and must be included in the sizing calculations:

Discharge Line (and Hot Gas Reheat Lines)

Provide vertical risers over 5 feet with a trap at the bottom of the riser. For all risers over 25 feet, add a trap for every 20 feet of rise. Traps may be either evenly spaced or at 20 foot increments.

Liquid Line

No traps required.

Suction Line

Provide vertical risers over 5 feet with a trap at the bottom of the riser. For all risers over 25 feet, add a trap for every 20 feet of rise. Traps may be either evenly spaced or at 20 foot increments.

Your unit was shipped with filter-drier(s) either installed in the evaporator section or filter-drier(s) shipped loose with the system. For multi-circuited units, each liquid line must have its own filter-drier. If the filter-drier was not factory installed, it must installed in the liquid line as close to the evaporator section as possible. Refer to the labeling on the device and ensure that it is installed with the proper orientation to the flow.

Any time a system is cut into for any reason (replace a TXV, change a compressor, etc.) you MUST also change the filter-drier. Failure to change the filter-drier will void any remaining warranty on the unit.