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Keeping a mini split clean and sanitary

As a service technician I see more ductless systems every year. They certainly aren't my favorite thing to have to work on. A common problem I see is heavy buildup of of black "biological growth "on the inside of the indoor units, especially on the blower wheel.
We currently clean these units with a bib kit, and pump sprayers with a chemical solution in it. The process would work better with a coil jet sprayer, but either way it can be a messy time consuming job.
Is there better way to clean these units? I've looked into ultraviolet lights as way to prevent contamination. Some units such as Carriers have a self cleaning mode built in, but that requires the homeowner to use it. That never happens so I'm still unsure of its effectiveness.


  • EdTheHeaterManEdTheHeaterMan Member Posts: 480
    The "Bib Kit" is the best thing I have found. along with the pump with a Sprayer nozzle to lightly "Pressure Wash" the coil and fan. Takes less them than removing the screws and accessing the interior with a washcloth. After doing that on one unit and taking over 4 hours to thoroughly clean the unit, I decided to try the bib/funnel idea and was completely sold. Now you need to teach your staff to use it properly. I find that is more of a challenge than anything. Getting the tech to take pride in doing the maintenance properly is often difficult.

    Tools don't always make for good results. the person using the tool is the most important part of the job.
  • clammyclammy Member Posts: 2,496
    It seems to me that the mini splits that where filthy where usually neglected and the filter never removed and cleaned and in what seems a lot of case homes that could use a good cleaning ( hi dust and animal dander ) home w a lot of pets seemed to fair worse . While I ve been in a few that never end up being very dirty . I think a lot has to do w the air quality inside the home . In cleaning them its all the same ,I started using anti fungal condensate pan treatment and it has seems to curb the worse ones a little bit ,I usually use the bib and a calogon non rinse evap cleaner and have some have said cleaned within a inch of its life , I,ll usually take the cover outdoor hose it off w water then spray w spray nine ,rinse and wipe off again w a dis infective wipe . Usually a good condensate line flush and call it a day . Now when I look at selling mini splits I make sure they understand that if they want proper operation and longevity then proper maintenance of indoor and outdoor equipment is a priority and being on top of cleaning the filter at a mim of every month if not mini splits may not be for them . I don’t bother quoting jobs that are in need of a good house cleaning why cause they will never clean the house what would make them clean a filter ? Nothing and of course it’s highly doubtful they will want to pay for any service so I try to be way up front about maintenance and costs . It’s sad that they do not a better filter for them but it is what it is . I ve always been a either eac or high media filter guy on all my installs and for last 20 years always 2 pleated for roof tops ,there’s nothing worse then having to clean evaporators whether it’s a roof top unit on a curb or a air handler in a attic always some liability in ceiling tiles or Sheetrock all depends .the cleaning of these units are usually neglected mainly I feel due to being time consuming and expensive w liability from water or cleaning damage stains and that’s it really up to the contractor to inform the customer about all cost up front including future maintaince . In closing I see more of the mold issues on multi head systems as opposed to single zone units . Peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
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