Mini Split Line Set: What Is It, and What Size Do You Need? Posted on July 27, 2016 Mini Split Line Sets: What You Need to Know Mini splits offer an energy-efficient way to cool and heat rooms without ductwork losses. However, an essential part of any ductless mini split system is the mini split line set. In this guide, we’ll explain what mini split line sets are, why choosing the correct size is critical, and how to find the right one for your system. What is a Mini Split Line Set? A mini split HVAC system consists of two main units: the outdoor condenser and the indoor air handler. These components are connected by a mini split line set, which ensures refrigerant circulates properly through the system. A line set comprises two semi-flexible copper pipes: Suction Line: The larger pipe that carries refrigerant in its gaseous state. Liquid Line: The smaller pipe that circulates refrigerant in its liquid state. Both lines are insulated and equipped with flare connections to create a pressure-resistant, leak-free seal. Without these pipes, refrigerant cannot flow effectively, making the line set a critical component of any mini split system. The Importance of Choosing the Right Mini Split Line Set Selecting the correct size line set is crucial for optimal performance: Too Large: Results in low refrigerant pressure, causing inefficient operation or system failure. Too Small: Increases pressure, leading to refrigerant flooding and potential damage. Since line sets cannot be resized or adjusted, purchasing the appropriate size for your mini split system ensures efficiency, performance, and longevity. Mini Split Line Set Sizes Line set size refers to the uninsulated width of both the suction line and liquid line, as well as the insulation thickness. Common line set sizes include: 1/4” and 3/8” 1/4” and 1/2” 1/4” and 5/8” 3/8” and 5/8” 3/8” and 3/4” Most mini split systems use R410A refrigerant, which requires 1/2” insulation on both pipes. All mini split line sets available on Total Home Supply feature this recommended insulation. How to Choose a Mini Split Line Set Step 1: Check Manufacturer Specifications The correct line set size depends on your mini split system. Always refer to the manufacturer’s specifications to ensure compatibility. For systems purchased at Total Home Supply, we list the recommended line set sizes directly on the product pages. Step 2: Determine Line Set Length Measure the distance between your indoor and outdoor units. Line sets are commonly available in lengths of: 15 feet 25 feet 50 feet Some systems support line sets up to 150 feet. When in doubt, choose a longer line set. Most systems require a minimum length of 15 feet to function correctly, while exceeding the manufacturer’s maximum limit can cause performance issues. Step 3: Use Copper Line Sets Always choose copper line sets over aluminum or hybrid options. Copper offers superior flexibility, durability, and compatibility with R410A refrigerant, which is standard in modern mini split systems. Mini Split Line Set Installation Installing a ductless mini split system, including the line set, requires professional expertise. Refrigerant setup involves precise electrical and HVAC knowledge. For safety and proper system operation, hire a licensed HVAC professional for installation. Conclusion Choosing the right mini split line set is essential for ensuring your ductless HVAC system performs efficiently and reliably. Consider the manufacturer’s specifications, required length, and construction material when selecting your line set. For expert advice and top-quality mini split line sets, contact us at 1-877-847-0050 or explore our website. Need help finding the perfect ductless system? Check out our Multi Zone Mini Splits Buying Guide. Mickey Luongo Mickey is the resident heating and air conditioning expert with over 15 years of experience in the industry.
Mini Split Line Sets: What You Need to Know Mini splits offer an energy-efficient way to cool and heat rooms without ductwork losses. However, an essential part of any ductless mini split system is the mini split line set. In this guide, we’ll explain what mini split line sets are, why choosing the correct size is critical, and how to find the right one for your system. What is a Mini Split Line Set? A mini split HVAC system consists of two main units: the outdoor condenser and the indoor air handler. These components are connected by a mini split line set, which ensures refrigerant circulates properly through the system. A line set comprises two semi-flexible copper pipes: Suction Line: The larger pipe that carries refrigerant in its gaseous state. Liquid Line: The smaller pipe that circulates refrigerant in its liquid state. Both lines are insulated and equipped with flare connections to create a pressure-resistant, leak-free seal. Without these pipes, refrigerant cannot flow effectively, making the line set a critical component of any mini split system. The Importance of Choosing the Right Mini Split Line Set Selecting the correct size line set is crucial for optimal performance: Too Large: Results in low refrigerant pressure, causing inefficient operation or system failure. Too Small: Increases pressure, leading to refrigerant flooding and potential damage. Since line sets cannot be resized or adjusted, purchasing the appropriate size for your mini split system ensures efficiency, performance, and longevity. Mini Split Line Set Sizes Line set size refers to the uninsulated width of both the suction line and liquid line, as well as the insulation thickness. Common line set sizes include: 1/4” and 3/8” 1/4” and 1/2” 1/4” and 5/8” 3/8” and 5/8” 3/8” and 3/4” Most mini split systems use R410A refrigerant, which requires 1/2” insulation on both pipes. All mini split line sets available on Total Home Supply feature this recommended insulation. How to Choose a Mini Split Line Set Step 1: Check Manufacturer Specifications The correct line set size depends on your mini split system. Always refer to the manufacturer’s specifications to ensure compatibility. For systems purchased at Total Home Supply, we list the recommended line set sizes directly on the product pages. Step 2: Determine Line Set Length Measure the distance between your indoor and outdoor units. Line sets are commonly available in lengths of: 15 feet 25 feet 50 feet Some systems support line sets up to 150 feet. When in doubt, choose a longer line set. Most systems require a minimum length of 15 feet to function correctly, while exceeding the manufacturer’s maximum limit can cause performance issues. Step 3: Use Copper Line Sets Always choose copper line sets over aluminum or hybrid options. Copper offers superior flexibility, durability, and compatibility with R410A refrigerant, which is standard in modern mini split systems. Mini Split Line Set Installation Installing a ductless mini split system, including the line set, requires professional expertise. Refrigerant setup involves precise electrical and HVAC knowledge. For safety and proper system operation, hire a licensed HVAC professional for installation. Conclusion Choosing the right mini split line set is essential for ensuring your ductless HVAC system performs efficiently and reliably. Consider the manufacturer’s specifications, required length, and construction material when selecting your line set. For expert advice and top-quality mini split line sets, contact us at 1-877-847-0050 or explore our website. Need help finding the perfect ductless system? Check out our Multi Zone Mini Splits Buying Guide.
June 29, 2016 at 10:58 AM Josh Upton says: Manufacturer sent larger line sets for recessed mini splits than required and the house is finished. Alot of sheetrock has to be removed to replace lines. Can I reduce part of the lines to keep from removing sheetrock,paint,insulation etc. Reply
June 29, 2016 at 11:05 AM Mickey Luongo says: Reducing the fittings will not solve the problem. The system will not function correctly without the properly sized lines. Reply
July 13, 2016 at 1:55 PM Max says: I am replacing my unit. Can I use the existing Line set? (The lines are 5 years old and they are the correct size for the new unit) Reply
July 13, 2016 at 7:07 PM Mickey Luongo says: You can use it since it is the same size. I would recommend having your contractor clean the line. As always, make sure to pressure test the line prior to charging the system. Reply
November 1, 2016 at 5:30 PM Jhemin says: I have an 18000 btu mini split ac, my problem is the suction line is not the same as the original 1/2 size..we already fixed a 5/8 suction line and 1/4 discharge line. My question is, is there any changes or problem in cooling? Reply
November 1, 2016 at 5:40 PM Mickey Luongo says: Your system will not work correctly if you do not use the correctly sized lines. If you try to use larger or smaller lines, the unit will not get the correct amount of refrigerant. Reply
November 1, 2016 at 6:37 PM Josh Upton says: A little less efficient on mine. Same exact problem wrong line set from manufacturer. Reply
February 4, 2017 at 12:16 PM Timothy Roderick says: Line set length: Will a hyper-heat mini-split installed with a 15′ long line set operate more efficiently then a unit installed with a 50′ line set?_________________________________ Placement in a windy location: The closest outdoor location to my indoor module is exposed to strong NW winds during the winter months. Could I construct a wind break / shield to protect my mini-split from these winds?______________________________________ This location is well shaded during the entire year; so I believe it would be an ideal location during hot summer months. Is this important?_______________________ Reply
February 13, 2017 at 1:26 PM CINDY CRIDER says: Can I Hook up 5 head units to one outside unit ? Reply
February 13, 2017 at 1:28 PM Mickey Luongo says: Certain outdoor units support this. Checkout our guide on multi zone mini splits here: https://www.totalhomesupply.com/multi-zone-mini-split-buying-guide Reply
March 28, 2017 at 10:16 PM santiago says: hi i want install a condencer unit with two head inside but i want put the outdoor in the roof and is like 75ft that is a probrem or i cant doin the way Reply
March 29, 2017 at 9:10 AM Mickey Luongo says: It depends on the specs of your system. For example, the LG LMU18CHV can go a maximum distance of 82 feet per zone. Other systems will be less. Reply
April 23, 2017 at 8:35 AM Nikeisha says: What size connection pipes does the Panasonic inverter 18000 btu use,we got 1\4 inch and 5\8 inches and the ac guy said its the wrong size Reply
April 24, 2017 at 9:30 AM Mickey Luongo says: It depends on your specific model, but most Panasonic 18,000 BTU systems require 1/4 and 1/2 inch line sets. Reply
April 24, 2017 at 4:09 PM Mickey Luongo says: No, the sizes are different depending on the system. Reply
June 30, 2017 at 11:04 AM john harris says: I have a 1.5 ton cooling only mini split with 3/8 liquid line and1/2 suction line. The new inverter drive equipment is 1/4 liquid line and 1/2 suction. It would be very difficult to replace the piping. I know that the system is metered refrigerant feed from outdoor unit to the indoor. The outdoor unit is 20 feet above the indoor. Any comments? Reply
June 30, 2017 at 12:03 PM Mickey Luongo says: You would need to replace the line set. Using the wrong size will cause the system to malfunction and void the warranty. Reply
August 8, 2017 at 9:33 PM Amerika McCann says: Are the measurements for these line sets measuring the Inner or outer diameter? Thanks. Reply
August 9, 2017 at 9:52 AM Mickey Luongo says: Refrigerant lines are measured by the outside diameter. Reply
August 25, 2017 at 2:02 PM Josh Upton says: My recessed mini splits condensate on trims after running about 30 minutes any suggestions on what to do? Reply
May 3, 2018 at 4:58 PM Mini Split Failures, Problems & Troubleshooting Guide says: […] use of a proper line set is also critical to system performance. Each mini split system will specify the proper size line […] Reply
July 2, 2018 at 11:29 AM Mini Split Accessories & Components - A Guide on Which You Need says: […] mini split component integral to the operation of your system is the line set, which is comprised of two semi-flexible copper pipes connecting the outdoor and indoor […] Reply
October 11, 2018 at 7:32 AM Joe says: If I’m hooking up a 3 zone unit with different size line sets do I need adapter to hook up lines to condenser Condenser has 3 -1/4 , 3/8 One of head unit is 1/4, 1,2 Reply
December 6, 2018 at 4:44 PM Ductless AC Mini Split Installation: How to Install, DIY + Placement says: […] Line sets* […] Reply
October 29, 2019 at 10:50 PM Lucy says: Can a 12k btu unit use 1/4 -3/8 line set or does it have to be 1/4-1/2 line set? Reply
October 30, 2019 at 9:03 AM Mickey Luongo says: It depends on the specific product you have. Each manufacturers requirements are different. Reply
April 1, 2023 at 4:21 AM Jacob says: Hi there, I’m having a hard time determining if I need to size the lineset based on the condensing unit’s BTU’s or the Zone’s BTU’s. I have a Bosch 27k 3 zone mini split. Each zone is 9000btu respectively. Logic is telling me that I will only need a lineset big enough to cover 9000btu on each head. If I had a single zoned 27k btu head then obviously I would need a larger lineset. Am I incorrect? Thanks Reply
April 1, 2023 at 12:39 PM Mickey Luongo says: Line set sizing is determined by the indoor unit. You must use the specific size the manufacturer calls for. Reply
