Air Dominion 1/4 in. x 3/8 in. Insulated Mini Split Line Set
Reviewed pricing, lead time, freight, and final configuration are confirmed during quote review before order release.
Air Dominion 1/4 in. x 3/8 in. Insulated Mini Split Line Set is the field-installed copper line pair used to connect a mini split indoor unit to its outdoor condenser when the run is longer than the boxed kit, when the boxed line set is replaced, or when a second zone is piped. It pairs a 1/4 in. liquid line with a 3/8 in. suction line, both insulated, with flared ends ready for standard flare service valves. This Air Dominion quoting record is presented as a reviewed accessory configuration, with final configuration confirmed during quote review before release.
Highlights
- 1/4 in. O.D. liquid line and 3/8 in. O.D. suction line, sold as a matched pair
- 1/2 in. insulation on the line pair for condensation control and efficiency
- Flared ends with flare nuts fitted, ready for standard mini split service valve connections
- Length options of 15, 25, 30, 35, and 50 ft to match the routed run
- Line size matches Air Dominion 9K and 12K class connections
Specification Table
| Liquid line | 1/4 in. O.D. |
| Suction line | 3/8 in. O.D. |
| Insulation | 1/2 in. wall |
| Connection | Flared, both ends |
| Available lengths | 15 / 25 / 30 / 35 / 50 ft |
| Sold as | Matched liquid + suction pair |
Included Equipment
- Insulated 1/4 in. liquid line with flare nuts
- Insulated 3/8 in. suction line with flare nuts
Installation Notes
- Confirm the connection sizes on the indoor and outdoor unit rating plates before ordering; line size is set by the equipment, not the run length.
- Keep the total run and vertical rise within the limits published for the connected system; long runs can require additional refrigerant charge, confirmed during quote review.
- Refrigerant-side work including flaring, evacuation, and charging verification should be completed by a qualified HVAC professional.
Warranty and Support
- Prepared for Air Dominion quote review. Final accessory configuration, coverage terms, and installation documents are confirmed before release.
- Accessory coverage follows the published Air Dominion accessory support terms confirmed during quote review.
Frequently Asked Questions
Which Air Dominion systems use this line size?
This 1/4 x 3/8 pairing matches Air Dominion single-zone systems in the 9K and 12K classes using 1/4 x 3/8 line connections. Confirm the labeled connection sizes on your unit during quote review.
Is the line set insulated?
Yes. The pair carries 1/2 in. insulation.
Are the ends flared?
Yes. Both lines arrive flared with flare nuts fitted for standard mini split service valves.
What if my wall-to-pad run is between lengths?
Select the next length up and coil the modest excess with a wide bend radius, or note the exact routed length in the quote request for review.
Documents
- Type Mini Split Accessory
- SKU AD-HVAC-ACC-MS-LINESET-1438-15
Download the available product documents below. If a document is not linked yet, use the SKU during quote review.
Project pricing, lead time, freight routing, and final configuration are confirmed during quote review before order release.
Support and request quote workflows stay available throughout specification and order planning.