One of the smartest innovations in the MRCOOL DIY mini split system is its pre-charged lineset. These refrigerant-filled, factory-sealed copper tubes make it possible for homeowners like you to install your own HVAC system — no special tools, no certification, no pro labor required.
But here’s the question that stumps a lot of DIYers: “Do I need the 25ft lineset or should I go with the 50ft option?”
For many standard installs, the 25ft lineset works fine. But for detached garages, basements, upstairs bonus rooms, or tricky layouts, a 50ft lineset can save you headaches, time, and money.
MRCOOL 5th Gen 50ft 1/4” x 1/2” Pre-Charged Lineset - DIY50-1412C-O
In this guide, I’ll share real-world scenarios where Savvy homeowners choose a 50ft lineset, plus tips to help you decide if it’s right for you.
📏 Why a 50ft Lineset Exists
Before we dive into the scenarios, let’s cover why MRCOOL offers both 25ft and 50ft lengths.
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The 25ft lineset is ideal for standard installs where the condenser sits just outside the wall.
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The 50ft lineset gives you extra reach for more complex layouts.
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Choosing 50ft upfront helps you avoid:
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Running short mid-install.
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Buying coupler kits.
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Adding extra joints (which increase leak potential).
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👉 According to Energy.gov, keeping refrigerant runs clean and efficient is critical to HVAC performance. The right length matters.
🏠 Scenario 1: Detached Garage Conversion
Imagine you’ve turned your detached garage into a home office or workshop. You need heating and cooling for year-round comfort — but the outdoor unit can’t sit right next to the garage wall. Maybe local codes, noise considerations, or landscaping push you to place it behind your house.
Why a 50ft Lineset Works Here:
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A 25ft lineset won’t reach across the yard.
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The 50ft line gives you the distance to connect the indoor air handler in your garage to the outdoor condenser behind your home.
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No need for couplers or multiple joints.
👉 For garage conversions, the 50ft option is almost always the right call.
🛋️ Scenario 2: Basement Family Room
Basements can be tricky. You may want to install an air handler in a finished basement, but the outdoor condenser can’t sit directly outside due to grading, drainage, or patio placement.
Why a 50ft Lineset Works Here:
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The lineset may need to run up through joists and out to a side wall before reaching the condenser.
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Routing through tight spaces adds distance.
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A 25ft line often comes up short.
With a 50ft, you get the flexibility to run the tubing cleanly and still have extra to coil neatly by the condenser.
🛏️ Scenario 3: Upstairs Bonus Room
Many homes have a bonus room above a garage — great for guests, offices, or kids’ playrooms. These rooms are notoriously hot in summer and cold in winter. A MRCOOL system is a perfect solution.
Why a 50ft Lineset Works Here:
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The indoor unit sits upstairs.
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The lineset has to snake through the attic, down the siding, and across to the condenser.
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The extra vertical and horizontal travel adds up fast.
👉 In this case, the 25ft line would leave you stranded. The 50ft ensures you can make the full run without stress.
🏢 Scenario 4: Small Rental Property
Landlords love MRCOOL systems because they reduce labor costs and speed up turnover. But rental properties often have non-standard layouts — meaning the condenser can’t always sit right outside the unit being cooled.
Why a 50ft Lineset Works Here:
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Multi-unit buildings sometimes require routing the lineset to a central condenser location.
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Installing multiple units across different apartments often means longer runs.
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Using 50ft linesets avoids piecing together couplers, which saves install time and reduces leak risks.
👉 For property owners, the convenience of 50ft linesets often outweighs the higher upfront cost.
🏕️ Scenario 5: Vacation Cabin
Remote cabins and vacation homes present unique installation challenges. You may need to route the condenser away from snow loads, animal activity, or rough terrain.
Why a 50ft Lineset Works Here:
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The outdoor unit is placed further away for protection.
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Rocky terrain or snow barriers force longer routing.
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The extra length ensures flexibility, especially when drilling through thick cabin walls.
👉 The 50ft line buys you peace of mind in unpredictable environments.
⚖️ Cost vs. Convenience
Let’s talk money.
25ft Lineset
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Lower upfront cost.
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Ideal for straightforward installs.
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May require coupler + extension if you guessed wrong.
50ft Lineset
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Higher upfront cost (about $200 more than 25ft).
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Saves you from buying couplers ($80–$100 each).
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Fewer joints = lower leak risk.
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Provides peace of mind.
👉 According to HomeAdvisor, professional labor can add $500–$2,000 to a mini split install. Spending a little more on the right lineset length upfront is far cheaper than redoing the install.
🧯 Savvy’s Pro Tips
Here’s what I always tell homeowners who are on the fence:
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Measure carefully. Start from the air handler, trace the path, and add extra for bends.
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Add 10–15%. Never order a lineset based on exact distance — you’ll need wiggle room.
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Choose longer if unsure. Better to coil extra tubing neatly than to come up short.
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Avoid couplers unless necessary. Each joint is a potential leak point.
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Plan your outdoor placement. Don’t just think about today — consider landscaping, noise, and future access.
👉 Energy Star stresses that proper installation is key to efficiency. Planning your lineset length is part of that.
🏡 Real-World Takeaways
Let’s recap the scenarios where Savvy homeowners go with 50ft:
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Detached garage → condenser across the yard.
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Basement → long routing through joists and side walls.
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Bonus room → vertical + horizontal travel adds up.
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Rental property → multi-unit layouts need longer runs.
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Cabin → terrain and weather demand flexibility.
If your install resembles any of these, the 50ft MRCOOL lineset is the smart choice.
📚 Verified External References
🎯 Final Take: Savvy’s Advice
Here’s the bottom line:
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The 25ft lineset is fine for simple, direct installs.
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The 50ft lineset is worth it when your install involves longer runs, multi-story layouts, or detached spaces.
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Spending a little more upfront saves you from the stress and cost of couplers or do-overs.
👉 For practical, budget-minded homeowners like you, the 50ft MRCOOL lineset is the peace-of-mind option. It ensures your DIY project succeeds the first time — with fewer risks, fewer leaks, and plenty of flexibility.
In the next topic we will know more about: What Is a Pre-Charged Lineset? How MRCOOL Makes DIY Installs Simple
