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Does Mitsubishi HyperHeat minisplits come pre-charged?

rsilvers Member Posts: 182
I got a quote for 11 units working from 4 condensers and the guy said he needed 25lbs of 410. Don't they come pre-charged? Perhaps you have to add a few oz to top off the lines?


  • jad3675
    jad3675 Member Posts: 127
    Yeah, they're only pre-charged for a certain lineset length.  Though...25lbs is a lot of refrigerant. 
    For reference, 36K BTU Fujitsu units come pre-charged with 8lbs. They're good for 240ft. 
    You should be able to find the submittal sheets for the Mitsubishi units online.
  • GW
    GW Member Posts: 4,699
    Context, what model Mitsubishi? We routinely add 8 to 10 pounds on the bigger double deckers.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
  • Ironman
    Ironman Member Posts: 7,377
    It totally depends on the matching indoor units, line set sizes and lengths and the capacity of the equipment. Mitsubishi has a program for calculating it or it can be done by hand, but it’s complex and critical that it’s done right. As Gary said, adding 8-10 pounds is typical on the larger units.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • ratio
    ratio Member Posts: 3,649
    Not enough information to know. Like @Ironman said, the software tells you the exact amount, they're critical-charge units.
  • wmgeorge
    wmgeorge Member Posts: 222
    It is my understanding, once you go beyond 2 heads per condensing (outside ) units that is where the problems begin. Regardless of what you hear from the Salesman. Do your research first.
    Old retired Commercial HVAC/R guy in Iowa. Master electrician.