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Fujitsu Mini Split AOU36RLXFZ ?

I can remove a fujitsu (AOU36RLXFZ) 3 ton mini split from a commercial space with 2 18,000 BTU wall mount evaps. The unit has been running for roughly 4 years constantly on low speed the condenser has been inside a fan room looks brand new. My question is how long do these units last? I would be using it in my house maybe 2-3 months a year whats the working life of this unit thanks Dan

Comments

  • ChrisJ
    ChrisJ Member Posts: 11,795
    edited August 2017
    Danscrew said:

    I can remove a fujitsu (AOU36RLXFZ) 3 ton mini split from a commercial space with 2 18,000 BTU wall mount evaps. The unit has been running for roughly 4 years constantly on low speed the condenser has been inside a fan room looks brand new. My question is how long do these units last? I would be using it in my house maybe 2-3 months a year whats the working life of this unit thanks Dan

    If installed properly it could easily go 15-20 years.

    If installed poorly, a few months to a few years.

    Minisplits need a very good vacuum pulled, preferably below 250 microns and they have a minimum lineset length you need to pay close attention to.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • GW
    GW Member Posts: 4,186
    Yes Chris pulling and holding a vac are two different animals.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
    ChrisJ
  • JUGHNE
    JUGHNE Member Posts: 8,557
    Proper evacuation and holding. Flow nitrogen gas if brazing of course.

    Power surges and hail stones have caused the only problems I have had with major brand name Mini's.
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 11,795
    edited August 2017
    GW said:

    Yes Chris pulling and holding a vac are two different animals.

    Good point, I should've mentioned that. "Pulled to" is misleading.


    To me, when I say "preferably below 250 microns" I mean with the system isolated from the pump after 15-20 minutes.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    GW
  • Big Ed_4
    Big Ed_4 Member Posts: 1,746
    Sounds like we are spliting hairs here ...
    I have enough experience to know , that I dont know it all
  • ChrisJ
    ChrisJ Member Posts: 11,795
    Big Ed said:

    Sounds like we are spliting hairs here ...

    Perhaps, but you'd be surprised.
    Isolating the pump and waiting to ensure there's no moisture in the system is important.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jack
    Jack Member Posts: 1,045
    Grab it and run. That is an excellent system.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,217
    Ever hooked up a vacuum gauge to the far side of a system? It tells the tale. Vacuum moves very sluggishly and slow, unlike pressure. The only way to see where a system is while under vacuum is to blank it off and see where the gauge stabilizes.

  • JUGHNE
    JUGHNE Member Posts: 8,557
    IIRC, most mini's only have a hose connection on the suction "wide" line. The way to flush & bleed air/nitrogen is to loosen the liquid flare nut.

    For me it seems that pumping down any system that is not virgin takes longer, perhaps the oil left in the inside coil and lineset.

    All the parts (TXV, reversing valve etc) subject to problems with moisture and contaminates are inside the outside unit. Inside coil is just copper tubing, should be all you have to contend with as long as the charge is clean inside the unit.
  • Danscrew
    Danscrew Member Posts: 120
    Thanks to all who responded. I was curious with the life span of the units
    I've done a few Mini splits in the past few years and will have no problem. With the removal and install and yes the biggest part of the install is drying the system (Nitrogen) by taking your time in pulling a vacuum. Micron gauge is a must
    Dave_154