25 ft 1/4" x 3/8" HVAC Installation Kit for Mini Split AC Systems | Pre-Insulated Copper Line Set Supplier

25 ft 1/4" x 3/8" HVAC Installation Kit for Mini Split AC Systems

The 25 ft 1/4" x 3/8" HVAC installation kit from DABUND is a complete solution for installing ductless mini split air conditioners and heat pump systems. The kit combines a 25 ft pre-insulated copper line set, communication wire, drain hose, wall sleeve, cover, and other essential installation accessories in one package.

The copper tubing uses a 1/4" liquid line and 3/8" suction line and is commonly selected for 9,000–12,000 BTU and 0.75–1.0 ton mini split systems. Both copper tube ends can be supplied pre-flared with nuts to help HVAC installers reduce preparation time on site.

Designed for HVAC contractors, distributors, importers, mini split brands, wholesalers, and project suppliers, this complete installation kit is available with OEM packaging, custom insulation, private-label printing, and multiple length options.

What Is Included in the 25 ft Mini Split Installation Kit?

Instead of purchasing refrigerant tubing and installation accessories separately, this complete mini split installation kit combines the primary components required to connect an indoor unit with an outdoor condenser.

• 25 ft pre-insulated copper line set – 1/4" + 3/8"

• Communication wire cable

• 3 m condensate drain hose

• Wall sleeve pipe

• Decorative wall cover

• Pre-flared copper tube ends with nuts

• Additional installation accessories according to kit configuration

For distributors and HVAC installers, using a matched installation kit can simplify purchasing, reduce the number of separately sourced components, and improve installation efficiency.

99.9% Pure Copper Refrigerant Line Set

The refrigerant tubing is manufactured from 99.9% pure copper. DABUND specifies copper tubing manufactured to ASTM B280 requirements using C12200 copper, providing the thermal conductivity, corrosion resistance, and durability required for HVAC and refrigeration installations.

1/4" Liquid Line + 3/8" Suction Line

The kit contains two refrigerant tubes: a 1/4" (6.35 mm) liquid line and a 3/8" (9.52 mm) suction line. This combination is commonly used with smaller ductless mini split air conditioning systems.

Pre-Flared Ends with Copper Nuts

Both ends of the copper tubing can be supplied pre-flared and fitted with nuts. This reduces additional tube preparation during installation and helps professional HVAC technicians connect the refrigerant lines more efficiently.

99.9% Pure Copper

White PE Insulated Pipe

Pre-Flared Copper Nut

Pre-Insulated Copper Line Set for HVAC Energy Efficiency

Factory-applied insulation helps reduce unwanted heat transfer, limits condensation, and protects the copper tubing during installation and operation. DABUND can provide both white PE insulation and black rubber insulation for different market and project requirements.

White PE Insulation

• Available thicknesses: 8 mm, 9 mm, 10 mm, 13 mm, 19 mm, and 25.4 mm

• Lightweight construction

• UV-resistant outer protection

• Suitable for customized printing and OEM branding

Black Rubber Insulation

• Available in multiple thickness options including 13 mm, 17 mm, 19 mm, and 25.4 mm

• Flexible construction for routing refrigerant lines

• Designed for thermal insulation and condensation control

• Suitable for residential and commercial HVAC applications

Three-Layer PE Insulation Structure

The white insulated copper tubing uses a multi-layer structure designed to provide physical protection and thermal insulation.

• Outer Layer: UV-resistant embossed PE film designed for wear and weather resistance.

• Middle Layer: IXPE foam providing thermal insulation and impact absorption.

• Inner Layer: Closed-cell insulation structure designed to reduce air and moisture penetration.

Thermal Insulation Pipe Production

Insulated Pipe Warehouse

Inner Insulation Layer

Is 1/4" x 3/8" Suitable for a 9,000–12,000 BTU Mini Split?

Yes. A 1/4" x 3/8" mini split line set is commonly used with 9,000 BTU and 12,000 BTU ductless air conditioners, corresponding approximately to 0.75–1.0 ton systems.

However, refrigerant line dimensions are determined by the specific air conditioner model. Installers and distributors should always verify the indoor/outdoor unit manufacturer's required liquid-line size, suction-line size, permitted piping length, and refrigerant specifications before installation.

Typical Applications

• 9,000 BTU ductless mini split air conditioners

• 12,000 BTU ductless mini split air conditioners

• Residential mini split systems

• Heat pump installations

• Light commercial HVAC projects

• Indoor-to-outdoor unit connections requiring approximately 25 ft of piping

HVAC Installation Kit Sizes and Insulation Options

In addition to the 25 ft 1/4" + 3/8" configuration, DABUND manufactures HVAC installation kits in multiple copper tube combinations, lengths, and insulation thicknesses for different air conditioning capacities and regional requirements.

Typical HVAC Line Set Size Reference

• 1/4" + 3/8": commonly used for 9K–12K BTU / approximately 0.75–1.0 ton systems.

• 1/4" + 1/2": commonly used for 12K–18K BTU / approximately 1.5–2.0 ton systems.

• 1/4" + 5/8": commonly used for 24K–30K BTU / approximately 2.0–2.5 ton systems.

• 3/8" + 5/8": commonly used for 36K–48K BTU / approximately 3.0–4.0 ton systems.

• 3/8" + 3/4": commonly used for 54K–72K BTU systems.

• 3/8" + 7/8": available for larger-capacity ductless HVAC applications.

Important: The capacities above are general selection references. Always follow the air conditioner manufacturer's specified refrigerant pipe dimensions before ordering or installing a line set.

Why Choose a 25 ft HVAC Installation Kit?

A 25 ft HVAC line set kit is suitable for many standard residential installations where the indoor evaporator and outdoor condenser are located relatively close to each other. It provides enough routing flexibility without requiring an unnecessarily long copper coil for many common installations.

• Ready-to-install configuration: combines line set and accessories in one package.

• Reduced sourcing work: fewer components need to be purchased separately.

• Pre-insulated tubing: helps save on-site insulation work.

• Pre-flared connections: reduce preparation requirements for professional installers.

• Suitable for wholesale: configurable for different markets and HVAC brands.

Mini Split, Heat Pump and HVAC Applications

The 1/4" x 3/8" pre-insulated copper line set and installation accessories are designed primarily for connecting indoor and outdoor units in split HVAC systems.

• Ductless mini split air conditioners

• Residential heat pumps

• Split air conditioning systems

• Residential HVAC installations

• Light commercial air conditioning projects

• HVAC replacement and new-installation projects

OEM & Wholesale HVAC Installation Kit Supplier

DABUND supplies HVAC installation kits for distributors, wholesalers, importers, contractors, and air conditioning brands. OEM and ODM services are available for companies requiring a customized product configuration or private-label solution.

• Custom copper line set lengths

• Multiple liquid-line and suction-line combinations

• White PE and black rubber insulation

• Custom insulation thickness

• Company name and specification printing

• Private-label branding

• Custom packaging

• Bulk-order configurations

For B2B buyers, the kit can be configured according to the target country's common HVAC sizes, insulation requirements, packaging preferences, and distribution channels.

Production Capacity for Bulk HVAC Orders

DABUND manufactures insulated copper pipe, mini split line sets, HVAC installation kits, aluminum pipe, and related HVAC components. Manufacturing capacity is designed to support recurring wholesale orders and larger distribution programs.

• Up to 1,000,000 pcs monthly production capacity

• HVAC manufacturing experience since 2008

• Sample production available for customized projects

• OEM and private-label production support

• Export supply for international HVAC markets

Why Choose DABUND as Your HVAC Installation Kit Manufacturer?

• HVAC manufacturing experience: production experience dating from 2008.

• Copper quality: 99.9% pure copper tubing with ASTM B280 / C12200 specifications.

• In-house insulation capability: supports insulation customization and printed branding.

• Flexible specifications: multiple pipe sizes, lengths, insulation materials, and thicknesses.

• OEM & ODM support: private labels, printed insulation, and customized packaging.

• Bulk production: production capability for wholesalers, importers, and HVAC distributors.

DABUND HVAC Factory

DABUND produces pre-insulated copper pipe, mini split line sets, HVAC installation kits, aluminum pipe, and HVAC accessories. Integrated manufacturing helps support quality control, specification customization, and stable B2B supply.

SGS Test Reports and HVAC Material Standards

Quality documentation is important for HVAC distributors, importers, and project buyers. DABUND states that its insulation materials have SGS test reports referencing standards including ASTM E84, UL 94, ASTM D1056, and ASTM G21, while the copper tubing is specified to ASTM B280 and C12200.

Buyers requiring specific compliance documentation should confirm the applicable test report, product specification, insulation material, and destination-market requirements when requesting a quotation.

DABUND at HVAC Exhibitions

DABUND participates in international HVAC exhibitions, giving distributors and customers opportunities to inspect mini split line sets, insulated copper tubing, HVAC installation kits, and related products directly.

FAQ About 25 ft 1/4" x 3/8" HVAC Installation Kits

What is included in a 25 ft 1/4" x 3/8" HVAC installation kit?

The DABUND kit includes a 25 ft pre-insulated 1/4" + 3/8" copper line set, communication wire cable, approximately 3 m of drain hose, wall sleeve and cover, pre-flared connections with nuts, and other installation accessories according to the selected package configuration.

What size mini split uses a 1/4" x 3/8" line set?

A 1/4" liquid line and 3/8" suction line are commonly used with 9,000–12,000 BTU mini split air conditioners, approximately 0.75–1.0 ton. Always verify the required refrigerant pipe dimensions specified by the air conditioner manufacturer before installation.

What are 1/4" and 3/8" copper tubing sizes in millimeters?

A 1/4" copper tube has an outside diameter of approximately 6.35 mm, while a 3/8" copper tube has an outside diameter of approximately 9.52 mm.

What is the difference between an HVAC installation kit and a mini split line set?

A mini split line set normally refers primarily to the paired refrigerant copper tubes. An HVAC installation kit is a more complete package that combines the line set with accessories such as communication cable, drain hose, wall sleeve, cover, and other installation components.

Are the copper line set ends pre-flared?

Yes. Both copper tube ends can be supplied pre-flared with nuts, reducing preparation work and allowing professional installers to connect the refrigerant lines more efficiently.

Why is the copper line set insulated?

HVAC refrigerant lines are insulated to reduce unwanted heat transfer and condensation. Factory-applied insulation also protects the tubing and eliminates the need to apply the primary insulation layer separately during installation.

Should I choose white PE or black rubber insulation?

Both options are designed for HVAC insulation. White PE insulation provides a lightweight, customizable solution with an outer protective layer, while black rubber insulation provides greater flexibility. The appropriate option depends on the project environment, required insulation thickness, regional standards, and buyer specifications.

Can the 25 ft HVAC installation kit be customized?

Yes. DABUND supports OEM and ODM orders with customized copper tube sizes, lengths, insulation materials, insulation thicknesses, company-name printing, private-label branding, and packaging.

Can I order different HVAC installation kit lengths?

Yes. In addition to 25 ft kits, DABUND manufactures line sets and installation kits in multiple metric and imperial lengths. Common configurations include approximately 3 m, 4 m, 5 m, 7 m, and 10 m, with additional customized lengths available according to order requirements.

What standards are referenced for DABUND copper tubing and insulation?

DABUND specifies copper tubing according to ASTM B280 using C12200 copper. Insulation-related SGS test documentation references ASTM E84, UL 94, ASTM D1056, and ASTM G21. Buyers should request the specific test documentation applicable to their ordered product and destination market.

Can distributors buy HVAC installation kits in bulk?

Yes. DABUND supplies HVAC installation kits for importers, distributors, wholesalers, contractors, and air conditioning brands. Bulk orders can be configured with different line set sizes, insulation options, packaging, and private-label requirements.

How do I choose the correct mini split installation kit?

Check the air conditioner manufacturer's required liquid-line diameter, suction-line diameter, piping length, insulation requirement, electrical cable specification, and refrigerant system requirements. Do not select a kit based only on BTU capacity, because line sizes can differ between HVAC brands and models.