The 1/4" x 3/8" mini split line set is a high-quality insulated copper tubing solution designed for ductless mini split air conditioners, heat pump systems, and HVAC refrigeration applications.

This line set consists of a liquid line (1/4") and suction line (3/8"), which work together to transfer refrigerant efficiently between the indoor and outdoor units. The factory-applied insulation ensures stable temperature control, reduces energy loss, and prevents condensation.

Manufactured from 99.9% pure copper, the tubing meets ASTM B280 and C12200 standards, ensuring long-term durability, corrosion resistance, and compatibility with modern refrigerants such as R410A and R32.

Technical Specifications of the 1/4" x 3/8" Mini Split Line Set

This HVAC copper line set is engineered to meet international standards for air conditioning and refrigeration systems.

Key Specifications

• Pipe Size: 1/4" + 3/8" (6.35 mm + 9.52 mm)

• Copper Material: 99.9% Pure Copper (C12200)

• Copper Standard: ASTM B280

• Insulation Material: Polypropylene or Rubber Insulation

• Working Temperature: -40°C to 120°C

• Pressure Rating: 2100 – 7000 PSI

• Flame Resistance: UL94 / ASTM E84 compliant

These specifications ensure safe refrigerant flow and reliable HVAC system performance under various operating conditions.

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Designed for 9000–12000 BTU Mini Split Air Conditioners

The 1/4" liquid line and 3/8" suction line configuration is commonly used for 0.75 ton to 1 ton mini split air conditioning systems, equivalent to 9,000–12,000 BTU capacity.

This makes the line set ideal for:

• Residential rooms and apartments

• Small offices

• Hotel rooms

• Light commercial HVAC installations

Using the correct line set size ensures optimal refrigerant flow and system efficiency.

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High-Purity Copper Tubing for Superior HVAC Performance

Copper is the preferred material for HVAC refrigerant piping systems due to its excellent physical properties.

Key benefits include:

• High thermal conductivity for efficient heat transfer

• Strong corrosion resistance for long-term use

• Ability to withstand high-pressure refrigerants

• Long service life with minimal maintenance

These advantages make copper tubing the industry standard for mini split line sets and refrigeration piping.

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Factory-Applied Insulation for Energy Efficiency

The insulated copper line set features high-density closed-cell insulation, designed to improve HVAC system efficiency.

Benefits include:

• Reduces heat loss and improves cooling performance

• Prevents condensation and moisture damage

• Enhances overall energy efficiency

• Simplifies installation with pre-insulated design

This insulation eliminates the need for additional wrapping on-site.

Features of pipe insulation tubing:

● Pipe Insulation, Material Black Rubber, Temp Range -40 Degrees to 120 Degrees.

● The pipe insulation has a better function of moisture condensation. Insulation material is both the insulation layer and moisture-proof layer.

● There is no need to drop the water vapor permeation protective layer so that it has a better moisture condensation function.

UV-Resistant and Flame-Retardant Insulation

The insulation is designed for both indoor and outdoor applications and meets international safety standards.

Key features:

• UV-resistant for outdoor durability

• Flame-retardant performance (UL94 compliant)

• Moisture and weather resistance

• Long-lasting structural stability

This ensures reliable performance in various environmental conditions.

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High Pressure Resistance for Modern Refrigerants

This mini split line set is designed to withstand high operating pressures up to 7000 PSI, which exceeds the requirements for modern refrigerants such as R410A.

This high-pressure capability ensures:

• Safe system operation

• Reduced risk of leaks or pipe failure

• Compatibility with high-efficiency HVAC systems

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Flexible Copper Coil for Easy Installation

The copper tubing is supplied in a flexible coil, making it easy to install in different building layouts.

Installation advantages include:

• Easy routing through walls and ceilings

• Reduced need for joints and connectors

• Faster installation time

• Lower risk of refrigerant leakage

This flexibility is especially useful for residential and retrofit HVAC projects.

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Wide Applications for HVAC and Refrigeration Systems

The 1/4" x 3/8" insulated copper line set is suitable for a wide range of applications:

• Ductless mini split air conditioners

• Heat pump systems

• Central air conditioning systems

• Refrigeration equipment

• Residential and light commercial HVAC installations

Its versatility makes it a reliable solution for HVAC professionals.

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Multiple Sizes and Customization Options Available

Professional HVAC manufacturers offer customization services to meet different installation requirements.

Available options include:

• Custom pipe sizes (1/4–1 1/8 inch range)

• Different insulation thickness options

• Custom lengths (15m, 20m, 25m, 30m, 50m, etc.)

• OEM logo printing

• Private label packaging

These options help distributors and contractors tailor products to their markets.

Mini Split Line Set

Size	Length	Insulation Black Rubber	Flame Resistant
1/4+3/8	15m/20m/25m/30m/50m	8mm/9mm/10mm/13mm/19mm/25.4mm	M1/B1
1/4+1/2	15m/20m/25m/30m/50m	8mm/9mm/10mm/13mm/19mm/25.4mm	M1/B1
1/4+5/8	15m/20m/25m/30m/50m	8mm/9mm/10mm/13mm/19mm/25.4mm	M1/B1
3/8+5/8	15m/20m/25m/30m/50m	8mm/9mm/10mm/13mm/19mm/25.4mm	M1/B1
3/8+3/4	15m/20m/25m/30m/50m	8mm/9mm/10mm/13mm/19mm/25.4mm	M1/B1
1/2+3/4	15m/20m/25m/30m/50m	8mm/9mm/10mm/13mm/19mm/25.4mm	M1/B1
3/8+7/8	15m/20m/25m/30m/50m	8mm/9mm/10mm/13mm/19mm/25.4mm	M1/B1

1/4 + 3/8 Line set for mini split systems used for 0.75TON - 1.0TON mini split air conditioner.

1/4 + 1/2 Insulated copper line set used for 1.5TON - 2.0TON mini split air conditioning.

1/4 + 5/8 Insulated copper piping used for 2.0TON - 2.5TON split air conditioner system.

3/8 + 5/8 Insulated copper tube apply for 3.0TON - 4.0TON ductless mini split air conditioner.

3/8 + 3/4 Insulated copper tubing used for 4.5TON - 6.0TON split air conditioner installation.

3/8 + 7/8 Insulated copper piping apply for 6.0TON - 8.0TON ductless mini split air conditioner.

Air conditioning copper line sets 1/4 + 3/8 used for 0.75P and 1P split air conditioning.

Copper pipe kit 1/4 + 1/2 commonly used for 1.5P and 2P mini split air conditioners.

1/4 + 5/8 Insulated copper line set used for 2P and 2.5air conditioner system.

3/8 + 5/8 Mini-split copper line set apply for 3P and 4P ductless mini split air conditioner.

3/8 + 3/4 Copper pipe kit used for 4.5P and 6P split aircon installation.

3/8 + 7/8 Insulated copper piping apply for 6P - 8p TON ductless mini split air conditioner.

1/4 + 3/8 Mini split line set used for 9000BTU and 12000 BTU split air conditioner.

Copper line set 1/4 + 1/2 commonly used for 12000 BTU and 18000 BTU mini split air conditioners.

1/4 + 5/8 Insulated copper line set used for 24000 BTU and 30000 BTU air conditioner system.

3/8 + 5/8 Mini-split line set apply for 36000 BTU and 48000 ductless air conditioner.

3/8 + 3/4 Copper line set used for 54000 BTU and 72000 split air conditioner installation.

3/8 + 7/8 Insulated copper pipe apply for 72000 BTU - 96000 BTU ductless mini split air conditioner.

Aircon copper line set 1/4 + 3/8 used for 9K and 12K split air conditioner.

High quality copper line set 1/4 + 1/2 commonly used for 12K and 18K mini split air conditioners.

1/4 + 5/8 Insulated copper line set used for 24K and 30K air conditioner system.

3/8 + 5/8 Mini-split line set apply for 36K and 48K ductless air conditioner.

3/8 + 3/4 Copper line set used for 54K and 72K split air conditioner installation.

3/8 + 7/8 Insulated copper piping apply for 72K - 96K ductless mini split air conditioner.

Why Choose a Professional HVAC Line Set Manufacturer

Working with an experienced manufacturer ensures high product quality and consistent performance.

Key advantages include:

• High-purity copper materials

• Strict quality control standards

• Advanced production equipment

• OEM and customization capabilities

• Competitive factory pricing

A professional supplier ensures reliability for large-scale HVAC projects and global distribution.

DABUND FACTORY

We produce Insulated Copper Pipe, Mini Split Line Set and Aluminum Pipe and HVAC Parts

SGS Certificate

Mini Split Line Set is made of Polypropylene or Black Rubber with UV Resistant, meets ASTM E 84, UL94, ASTM D1056 and ASTM G 21

Exhibition

We join the exhibitions all over the word, just to facilitate customers to experience our mini split line set face to face.

FAQ

1.What is a 1/4" x 3/8" mini split line set used for?

A 1/4" x 3/8" mini split line set is used to connect the indoor and outdoor units of a ductless mini split air conditioner or heat pump system. The copper tubing allows refrigerant to circulate between the evaporator and condenser, ensuring efficient cooling and heating performance. The insulation layer helps maintain temperature stability and reduces energy loss.

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2.What size mini split system requires a 1/4" x 3/8" line set?

A 1/4 inch liquid line and 3/8 inch suction line is typically used for 9,000 BTU to 12,000 BTU mini split systems. These systems are commonly installed in bedrooms, small offices, apartments, and residential applications.

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3.Why is copper used for HVAC refrigerant line sets?

Copper is the preferred material for HVAC refrigerant piping because of its excellent thermal conductivity, durability, and corrosion resistance. It can withstand high refrigerant pressures and ensures efficient heat transfer between system components, making it ideal for air conditioning and refrigeration systems.

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4.Does the mini split line set come pre-insulated?

Yes. Most mini split line sets come with factory-applied insulation that helps maintain refrigerant temperature, prevents condensation, and improves system efficiency. Pre-insulated copper pipes also simplify installation by eliminating the need for additional insulation work on-site.

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5.Can the copper line set be cut during installation?

Yes. The insulated copper line set can be cut to the required length depending on the installation distance between indoor and outdoor units. HVAC technicians often trim the pipe to reduce excess tubing and minimize the number of joints, which helps prevent refrigerant leaks.

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6.Is this HVAC line set compatible with modern refrigerants?

Yes. High-quality copper line sets manufactured according to ASTM B280 standards are compatible with modern refrigerants such as R410A and R32. These refrigerants require durable copper pipes that can withstand higher operating pressures.

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7.How long does a mini split copper line set last?

A properly installed mini split copper line set can last 20 years or more. Copper tubing is highly durable and resistant to corrosion, while the insulation protects it from environmental damage, ensuring long-term HVAC system reliability.

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8. Can this line set be used for both residential and commercial HVAC systems?

Yes. The 1/4" x 3/8" mini split line set is suitable for both residential and light commercial HVAC applications, including homes, apartments, offices, and small retail spaces. Its flexibility and durability make it a versatile solution for various installations.

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9.What insulation thickness is recommended for copper line sets?

The recommended insulation thickness depends on the installation environment. Common options include 8 mm, 10 mm, 13 mm, 19 mm, and 25 mm. Thicker insulation is typically recommended for outdoor installations or extreme temperature conditions to improve energy efficiency.

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10.Why choose a professional HVAC line set manufacturer?

Choosing a professional HVAC line set manufacturer ensures consistent product quality, high-purity copper materials, and reliable insulation performance. Experienced manufacturers also provide OEM customization, strict quality control, and international certifications, making them trusted partners for HVAC contractors and distributors worldwide.