
MRCOOL® DIY® Quick Connect Pre-Charged Line Sets: Tested for Perfection
The Quick Connect® line sets from MRCOOL® are a critical component of our DIY® Ductless Mini-Split Systems as they simplify the installation process. Without these essential parts, one would need costly HVAC tools to connect, braze, and charge the line set, making the acquisition of a new HVAC system considerably more expensive. Our DIY® Quick Connect line sets have proven to be remarkably dependable throughout our initial development and continued use, earning a patent for their importance and ease of use in the installation of the MRCOOL® DIY® Ductless Mini-Split.
Given the uniqueness of our Quick Connect® pre-charged line set connections within the industry, we entrusted 360º Product Testing, a highly trusted resource for product testing, to perform a series of quality assurance tests to evaluate and ensure their leak resistance. 360º Product Testing has worked with corporations and organizations like the Department of Homeland Security, LG, PepsiCo, and the U.S. Air Force, Army, and Navy. Through this product testing session, we can guarantee that we consistently provide products of the highest quality, ensuring the best possible comfort experience for our customers.
In October 2022, we sent 360º Product Testing eight coupler assemblies, and testing began promptly.

Before any connections were made, 360º recorded data. As they assembled the Quick Connect® couplers, they observed that the design of the fittings, with each connecting part having a spring-loaded valve to seal the fitting once connected, allowed for corrections and alignment to prevent cross-threading before connecting. 360º Product Testing characterized the fitting process as “an easy connection unlikely to be improperly done.”
Once the couplings were connected, 360º Product Testing determined the leak-free functionality of our pre-charged line set. To accomplish this, the connected fitting assemblies were subjected to hydrostatic pressure testing at a minimum of 400 PSI for at least eight hours. To obtain the most accurate readings and minimize temperature swings that may affect pressure, the tests were conducted in an environmental chamber. At this pressure, which is comparable to normal operating pressure, the couplers did not leak.
One last obstacle the couplers overcame was a pull test to evaluate the strength of the connection. One coupler was randomly selected to undergo a pull test, where it was placed in a test stand fitted with a force gauge. One end of the coupler was secured to the test stand, while the other end was attached to the force gauge, and tension was applied to confirm if the connection held. The tension was then increased to just over 500 pounds of force, and the coupler passed with flying colors.
We appreciate 360º Product Testing for the opportunity to have our line set connections tested by such a trusted company, and we are thrilled to announce that their findings confirm that our pre-charged line sets are as reliable and easy-to-use as we claim.
If you are interested in evaluating the MRCOOL® DIY® Ductless Mini-Split and its DIY® Quick Connect® Pre-Charged Line Sets, please visit our Where to Purchase page at https://mrcool.com/where-to-purchase/ or take a look at https://mrcooldiy.com/.
For dependable innovation and substantial savings, choose MRCOOL®.
We’ve got the units installed but it won’t come on.
Please give us a call at 270-366-0457 as soon as possible.
What line lengths are available? I have one room through the wall from the outside until and one that is 30 feet away.
The typical line set length that comes with the single-zone DIY Ductless Mini-Split is 25′, but you can purchase longer line sets at our retailer, as well as couplers to link additional line sets.
Can I purchase a ceiling cassette? My Home Depot doesn’t seem to find it in their catalog. It is on your website. I prefer to have a ceiling unit as one of my zones. Can I purchase it directly from you or is there a retailer in my area that I can purchase the ceiling cassette DYII unit from.? I need a 9000 BTU capacity. Thank you.
We don’t sell direct, so you’ll need to purchase one from a retailer. Here’s the model number for the 9k BTU DIY Ceiling Cassette:
DIY-09-HP-WMAH-230C.
Do you offer dealer programs? I would love to sell your products.
Please visit https://mrcool.com/dealer-signup/!
Interested in a couple units
Please give us a call at 270-366-0457, or visit our “Where to Purchase” map at https://mrcool.com/where-to-purchase/ for retailers near you!