20 ft 1/4" x 3/8" Mini Split Installation Kit with HVAC Accessories
The DABUND 20 ft 1/4" x 3/8" mini split installation kit is a complete HVAC installation package designed for compatible ductless mini split air conditioners, heat pumps, and split AC systems. The kit combines a 20 ft pre-insulated copper refrigerant line set with communication cable, condensate drain hose, wall pipe, protective cover, pre-flared connections, and other essential installation accessories.
The refrigerant tubing consists of a 1/4" (6.35 mm) liquid line and a 3/8" (9.52 mm) suction line. This combination is commonly found on certain smaller mini split systems, including many 9,000–12,000 BTU models, although the correct line size must always be verified from the specific HVAC equipment manufacturer's installation manual.
Made from 99.9% pure copper, the tubing can be supplied according to ASTM B280 and C12200 specifications. DABUND also supports OEM and ODM customization for HVAC distributors, wholesalers, importers, contractors, project suppliers, and private-label air conditioning brands.
Product: Complete Mini Split Installation Kit
Line Set Size: 1/4" + 3/8" / 6.35 mm + 9.52 mm OD
Length: 20 ft / approximately 6.10 m
Copper: 99.9% pure copper
Insulation: White PE or black rubber options
Connections: Pre-flared copper ends with flare nuts
Accessories: Communication cable, drain hose, wall pipe, cover and selected fittings
Applications: Mini split AC, ductless heat pumps and compatible split HVAC systems
What Is Included in the 20 ft Mini Split Installation Kit?
This all-in-one mini split installation kit combines refrigerant piping with commonly required installation accessories. Supplying the components together helps HVAC professionals reduce sourcing work and gives distributors a convenient packaged solution for compatible mini split installations.
20 ft pre-insulated copper line set – 1/4" liquid line + 3/8" suction line
Pre-flared copper ends with matching flare nuts
Communication wiring cable for compatible indoor and outdoor units
Condensate drain hose
Wall pipe and protective cover
Additional installation fittings and accessories according to the selected kit configuration
20 ft Pre-Insulated Refrigerant Line Set
The paired refrigerant tubing measures approximately 20 ft (6.10 m). This length is useful for many residential and light commercial installations where the indoor and outdoor units are relatively close but require more routing flexibility than a very short line set.
Pre-Flared Copper Ends with Nuts
The copper tubing can be supplied with factory-prepared flare ends and matching nuts. When the flare size and connection requirements match the HVAC equipment, this reduces field tube preparation and helps professional installers complete refrigerant connections more efficiently.
Communication Cable, Drain Hose and Wall Components
The kit can include communication cable for compatible indoor-to-outdoor electrical connections, a drain hose for indoor-unit condensate removal, and wall penetration components that help create a cleaner and better-protected installation.
1/4" x 3/8" Copper Refrigerant Line Set
1/4" Liquid Line
The smaller copper tube has an outside diameter of 1/4" or approximately 6.35 mm. In compatible mini split systems, this tube is commonly used as the liquid refrigerant line.
3/8" Suction Line
The larger copper tube has an outside diameter of 3/8" or approximately 9.52 mm. It is commonly used as the suction or vapor line when specified by the HVAC manufacturer.
99.9% Pure Copper
DABUND line sets use high-purity copper selected for HVAC and refrigeration piping. Copper combines thermal conductivity, corrosion resistance, workability, and long-term durability for professional refrigerant piping applications.
ASTM B280 and C12200 Specifications
The copper tubing can be supplied according to ASTM B280 requirements using C12200 copper according to the ordered product specification.
20 ft Mini Split Installation Kit Technical Specifications
| Feature | Specification |
|---|
| Product Type | Complete Mini Split HVAC Installation Kit |
| Line Set Length | 20 ft / approximately 6.10 m |
| Liquid Line Diameter | 1/4" / approximately 6.35 mm OD |
| Suction Line Diameter | 3/8" / approximately 9.52 mm OD |
| Material | 99.9% Pure Copper |
| Copper Specification | ASTM B280 / C12200 according to ordered specification |
| Insulation | Factory-applied White PE or Black Rubber Options |
| Connections | Pre-Flared Copper Ends with Flare Nuts |
| Included Accessories | Communication Cable, Drain Hose, Wall Pipe, Cover and Selected Accessories |
| Applications | Mini Split AC, Ductless Heat Pump and Compatible HVAC Systems |
| Refrigerant Applications | R410A, R32 and other systems when tubing specification matches equipment requirements |
| OEM Options | Length, Copper Size, Insulation, Printing, Packaging and Kit Components |
Factory-Applied Insulation for HVAC Efficiency and Condensation Control
Factory-applied insulation surrounds the refrigerant copper tubing before shipment. Correctly specified insulation helps reduce unwanted heat transfer, limit condensation on cold refrigerant piping, protect the tube surface, and reduce insulation work during installation.
White PE Insulation
White PE insulation is available in multiple thicknesses including approximately 8 mm, 9 mm, 10 mm, 13 mm, 19 mm, and 25.4 mm. Different thicknesses can be selected according to climate, application, condensation-control requirements, and customer specifications.
Black Rubber Insulation
Black rubber insulation is also available, with common thicknesses including approximately 13 mm, 17 mm, 19 mm, and 25.4 mm according to the ordered configuration.
Condensation Protection
Closed-cell insulation helps limit contact between cold refrigerant tubing and warm humid air, reducing surface condensation and helping protect surrounding building materials.
UV and Weather Resistance
Selected insulation configurations provide UV and environmental resistance for exposed HVAC applications. Additional line-set covers or protective conduit may still be appropriate for prolonged outdoor exposure depending on project requirements.
Insulation Test Standards
Depending on the selected insulation material and specification, DABUND test documentation can reference standards including ASTM E84, UL 94, ASTM D1056, and ASTM G21. Buyers requiring compliance documentation should confirm the test report applicable to the exact insulation configuration being ordered.

99.9% Pure Copper

White PE Insulated Pipe

Pre-Flared Copper Nut
Multi-Layer PE Insulation Structure
DABUND white PE insulation can use a multi-layer construction designed to provide thermal protection, moisture resistance, and physical protection for refrigerant copper tubing.
Outer Layer: protective PE surface designed for environmental and installation resistance
Middle Layer: foam insulation that helps reduce thermal transfer
Inner Layer: closed-cell structure designed to reduce moisture penetration


Thermal Insulation Pipe Production

Insulated Pipe Warehouse

Inner Insulation Layer
Is 1/4" x 3/8" Suitable for 9,000–12,000 BTU Mini Splits?
A 1/4" liquid line and 3/8" suction line are commonly found on many smaller ductless mini split systems, including certain 9,000 BTU and 12,000 BTU air conditioners and heat pumps.
However, BTU capacity alone does not determine the required refrigerant line size. Different HVAC brands and models with similar nominal capacities can specify different liquid and suction pipe diameters.
Check These Specifications Before Ordering
Required liquid-line diameter
Required suction-line diameter
Refrigerant type
Minimum and maximum permitted line length
Maximum indoor-to-outdoor elevation difference
Additional refrigerant charge requirements
Communication cable specification
R410A and R32 HVAC Applications
The copper line set can be supplied for HVAC systems using refrigerants such as R410A and R32 when the tube diameter, wall thickness, pressure rating, cleanliness, fittings, installation method, and HVAC equipment specifications are correctly matched.
Refrigerant compatibility should not be determined from pipe diameter alone. Always follow the HVAC manufacturer's technical requirements and applicable installation codes.
Applications for the 20 ft Mini Split Installation Kit
This complete installation kit is suitable for HVAC equipment that requires a 1/4" x 3/8" refrigerant line and can accommodate approximately 20 ft of piping.
Ductless mini split air conditioners
Mini split heat pump systems
Residential split AC installations
Bedrooms and apartments
Condominiums
Small offices
Light commercial HVAC applications
HVAC replacement and retrofit projects
Why Choose a 20 ft Mini Split Installation Kit?
A 20 ft installation kit is useful for projects where the indoor and outdoor units are moderately separated. It provides more routing flexibility than very short line sets while reducing unnecessary excess tubing on compact installations.
All-in-one sourcing: refrigerant lines and installation accessories are supplied together
20 ft working length: suitable for many residential installation layouts
Factory insulation: reduces field insulation work
Pre-flared connections: reduce copper preparation requirements
OEM availability: suitable for HVAC distributors and private-label brands
Installation Tips for Best Results
Measure the Complete Routing Path
Measure the actual route between the indoor and outdoor units before installation. Include wall penetrations, bends, final connection positions, and any required service loop when determining whether the 20 ft line set is long enough.
Avoid Sharp Bends and Kinks
Use appropriate HVAC copper tube-bending methods and maintain a suitable bend radius. Flattened or kinked refrigerant tubing can restrict refrigerant flow and should not be installed.
Protect Insulation at Wall Penetrations
Use the wall pipe, protective cover, line-set cover, or other suitable protection where tubing passes through walls or exposed locations. Avoid tearing or excessively compressing the insulation.
Secure the Refrigerant Lines
Use suitable HVAC supports, clips, brackets, or straps along the piping route to reduce vibration, prevent sagging, and protect the insulation.
Use the Correct Flare-Nut Torque
Flare nuts should be tightened to the torque specified by the equipment manufacturer. Incorrect torque can contribute to damaged flare connections or refrigerant leakage.
Maintain the Correct Drain Hose Slope
The condensate drain hose should be routed with the required downward slope according to the indoor unit manufacturer's instructions so water can drain correctly.
Leak Test and Evacuate Before Startup
After the refrigerant piping is connected, follow the equipment manufacturer's procedures for leak checking, pressure testing where applicable, vacuum evacuation, refrigerant adjustment, valve operation, and system commissioning.

Available Mini Split Installation Kit Sizes
DABUND manufactures mini split installation kits in multiple copper tube combinations, lengths, and insulation thicknesses for different HVAC equipment and international markets.
| Size | Length | White PE Insulation | Flame Resistant |
|---|
| 1/4 + 3/8 | 3m / 4m / 5m / 7m / 10m | 8mm / 9mm / 10mm / 13mm / 19mm / 25.4mm | M1 / B1 |
| 1/4 + 1/2 | 3m / 4m / 5m / 7m / 10m | 8mm / 9mm / 10mm / 13mm / 19mm / 25.4mm | M1 / B1 |
| 1/4 + 5/8 | 3m / 4m / 5m / 7m / 10m | 8mm / 9mm / 10mm / 13mm / 19mm / 25.4mm | M1 / B1 |
| 3/8 + 5/8 | 3m / 4m / 5m / 7m / 10m | 8mm / 9mm / 10mm / 13mm / 19mm / 25.4mm | M1 / B1 |
| 3/8 + 3/4 | 3m / 4m / 5m / 7m / 10m | 8mm / 9mm / 10mm / 13mm / 19mm / 25.4mm | M1 / B1 |
| 1/2 + 3/4 | 3m / 4m / 5m / 7m / 10m | 8mm / 9mm / 10mm / 13mm / 19mm / 25.4mm | M1 / B1 |
| 3/8 + 7/8 | 3m / 4m / 5m / 7m / 10m | 8mm / 9mm / 10mm / 13mm / 19mm / 25.4mm | M1 / B1 |
Mini Split Installation Kit Size Selection Guide
Different HVAC systems require different liquid-line and suction-line sizes. The following is a general product reference only. Always verify the required pipe dimensions from the exact air conditioner or heat pump installation manual.
| Line Set Size | General Application Reference |
|---|
| 1/4" + 3/8" | Commonly found on certain smaller 9K–12K mini split systems |
| 1/4" + 1/2" | Commonly found on certain small-to-medium mini split systems |
| 1/4" + 5/8" | Available for larger mini split applications when specified |
| 3/8" + 5/8" | Higher-capacity HVAC applications when specified |
| 3/8" + 3/4" | Larger split HVAC applications when specified |
| 3/8" + 7/8" | Large-capacity HVAC applications when specified |
Important: Do not choose refrigerant pipe dimensions based only on BTU, tonnage, or horsepower. The equipment manufacturer's specified liquid-line and suction-line sizes should determine the correct installation kit.
OEM Mini Split Installation Kit Manufacturer
DABUND supplies complete mini split installation kits for HVAC distributors, wholesalers, importers, contractors, project suppliers, and private-label air conditioning brands.
Custom Kit Lengths
Common kit lengths include 3 m, 4 m, 5 m, 6 m, 7 m, 8 m, and 10 m. Additional lengths can be discussed according to project requirements and OEM order quantity.
Custom Copper Tube Sizes
Different liquid-line and suction-line combinations are available for HVAC markets requiring different equipment specifications.
Custom Insulation
Buyers can select different insulation materials and thicknesses according to climate, application, target-market requirements, and customer specifications.
Private Label and Logo Printing
DABUND supports OEM and ODM branding, including company logos, product dimensions, length markings, labels, cartons, and private-label packaging.
Why Choose DABUND as Your Mini Split Installation Kit Supplier?
HVAC Manufacturing Experience Since 2008
DABUND has produced HVAC products since 2008, including mini split installation kits, insulated copper pipe, refrigerant line sets, aluminum pipe, and other HVAC components.
Large-Volume Production
DABUND factory information states production capacity of up to approximately 1,000,000 pieces per month depending on product configuration, supporting wholesale and recurring distribution orders.
In-House Insulation Production
In-house insulation manufacturing provides greater control over insulation thickness, appearance, printed markings, customization, and production scheduling.
B2B Wholesale and Export Supply
DABUND supports distributors, importers, contractors, and HVAC brands with bulk supply, custom configurations, private-label solutions, and international trade arrangements.
DABUND HVAC Factory
DABUND manufactures mini split installation kits, insulated copper pipe, refrigerant line sets, aluminum pipe, and other HVAC parts for international customers.

SGS Testing and HVAC Material Standards
DABUND copper tubing can be supplied according to ASTM B280 and C12200 specifications. Depending on the selected insulation material and product configuration, test documentation can reference ASTM E84, UL 94, ASTM D1056, and ASTM G21.
Buyers requiring specific compliance documents should request the technical data and test report applicable to the exact configuration being ordered.

DABUND HVAC Exhibitions
DABUND participates in international HVAC exhibitions where distributors, contractors, importers, and professional buyers can evaluate mini split installation kits, insulated copper tubing, line sets, and related HVAC products.

FAQ About 20 ft 1/4" x 3/8" Mini Split Installation Kits
What is included in a 20 ft mini split installation kit?
The DABUND kit can include a 20 ft pre-insulated 1/4" x 3/8" copper line set, communication wiring cable, condensate drain hose, wall pipe, protective cover, pre-flared copper ends with flare nuts, and selected installation accessories.
What is the difference between a mini split line set and an installation kit?
A mini split line set mainly refers to the paired refrigerant copper tubes. A complete installation kit combines those copper lines with additional components such as communication cable, drain hose, wall pipe, cover, and installation accessories.
What do 1/4" and 3/8" mean?
They refer to the outside diameters of the two refrigerant copper tubes. The 1/4" tube is approximately 6.35 mm OD and the 3/8" tube is approximately 9.52 mm OD.
What mini split size uses a 1/4" x 3/8" line set?
This pipe combination is commonly found on certain smaller mini split systems, including many 9,000–12,000 BTU models. However, the exact piping dimensions must be confirmed from the HVAC manufacturer's installation manual.
Is 20 ft long enough for a mini split installation?
It is suitable when the complete routed distance between the indoor and outdoor units fits within approximately 20 ft after allowing for bends and final connections. Measure the actual route before ordering.
Can the 20 ft copper line set be shortened?
Yes. A qualified HVAC technician can shorten the copper tubing when appropriate. Newly prepared connections should follow the manufacturer's specified flaring, brazing, torque, testing, evacuation, and commissioning procedures.
Are the copper line ends pre-flared?
Yes. DABUND can supply the refrigerant copper tubing with pre-flared ends and matching nuts for faster professional installation.
Is the copper line set factory insulated?
Yes. The copper tubing is supplied with factory-applied insulation designed to reduce unwanted heat transfer, limit condensation, and reduce field insulation work.
Can this mini split installation kit be used outdoors?
Selected insulation configurations are suitable for outdoor HVAC applications. For prolonged sunlight, weather, or physical exposure, additional line-set covers or protective conduit may be appropriate.
Can the kit be used with R410A or R32?
It can be supplied for compatible R410A and R32 applications when the copper tube diameter, wall thickness, pressure rating, fittings, cleanliness, and HVAC equipment requirements are correctly matched.
Does a longer refrigerant line require additional refrigerant?
It may. Many mini split systems contain a factory refrigerant charge for a specified standard piping length. Additional refrigerant may be required when the installed line exceeds that length, according to the manufacturer's charge-per-foot or charge-per-meter specification.
Can DABUND customize the installation kit for my brand?
Yes. DABUND supports OEM and ODM services including custom copper sizes, kit lengths, insulation materials, insulation thicknesses, logo printing, product markings, labels, cartons, accessories, and private-label packaging.
Is DABUND a manufacturer or trading company?
DABUND is a manufacturer of mini split installation kits, insulated copper pipes, HVAC refrigerant line sets, aluminum pipes, and related HVAC parts.
Can I get a sample before bulk ordering?
Yes. DABUND can provide up to 3 pieces of free samples for evaluation. Buyers normally cover the express shipping cost.
Can DABUND print my logo?
Yes. DABUND accepts OEM and ODM orders and can customize logos, product markings, labels, cartons, and private-label packaging.
What payment terms are available?
Common payment methods can include T/T, L/C at sight, credit card, and other agreed payment methods according to order details.
What delivery terms does DABUND support?
DABUND can support international trade terms including EXW, FOB, CFR, CIF, and other agreed Incoterms according to customer logistics requirements.
What is the typical delivery time?
Typical production and delivery preparation is approximately 15–20 days depending on order quantity, customization requirements, and current production scheduling. Urgent orders can be discussed before confirmation.