Checklist - How to clean your ductless mini split HVAC system in a few easy steps.

Posted on Jun 17, 2014

Mini Split Cleaning Made Easy

Ductless mini split systems - or simply mini splits - are air conditioning systems that have taken off in popularity here in the USA recently. However, these units have long been the HVAC system preference in regions like Asia due to their small size and large cooling power as well as their power efficiency. 

mini split cleaning systems

Split air conditioner systems act very similarly to regular ducted systems except they have no ducts. They are simply an air handler (evaporator) attach to a wall or ceiling which in turn is attached to a condenser unit outside. As such, ductless mini split systems require consistent, ongoing maintenance to maintain their performance and efficiency. 

Basic maintenance should occur at least annually and in most areas twice a year. If you live in particularly dusty areas or have recently undergone gone construction, you may want to clean more often. 

There are two parts of the system that need to be maintained, but before that is discussed, make sure to turn all power to the system off. 

The outdoor condenser, which should be cleaned/rinsed with water twice a year to remove dirt and pollen from the coils. Then the indoor unit (aka blower unit or evaporator) coils also need to be cleaned. The washable filters should be vacuumed or rinsed according to the manufacturer’s directions. 

The coil and the blower wheel/“squirrel cage”  can be cleaned less frequently since they tend to attract the smaller particles of dirt and dander in the air.  Factors including people, pets, and location can increase the fouling time of the coil and blower wheel.  That debris, when mixed with moisture also causes the blower wheel to get gunked up and will be out of balance.  These wheels can also be great breeding grounds for bacteria. 

Cleaning Mini Split Systems is Easy.

At IAQ Supply House we recommend the use of the Mini Split Bib Kit when cleaning your blower unit/evaporator. This all-in-one kit helps keep your room clean and protected as it captures all the water and cleaner you will use and safely funnels it away into the included 5-gallon bucket. If you are not using the Mini Split Bib Kit, then make sure you are protecting walls and area with drop cloths in case of overrun of fluids. 

We also recommend the CoilJet CJ-125 coil cleaning system. This portable coil washer produces 125 psi of cleaning pressure with only a .5 gallon/minute flow rate. Plus, it's battery operated and rechargeable for easy transport and use. 

If you are not using the CoilJet system then wet the coil with a fine mist from a pump sprayer, and then use Mini Split First Aid Kit. This product contains aerosol versions of Micro Coil Clean and Mold Control, and EPA registered mold and mildew inhibitor. Together, they will clean and protect the coils and blower wheel from mold and mildew.

Grab the BBJ Micro Coil clean. This aerosol coil cleaner is a low-foam spray, so it foams just enough to lift the dirt off the coil, but not enough to make a mess.  The actuator on the micro coil clean gives you a stream like a wasp spray to help knock that dirt and debris loose off the blower wheel.  Follow it up with a misting action of water and let air dry. Once the coils and blower fan wheel are completely dry, apply BBJ Mold Control for HVAC Systems and Air Ducts to prevent mold and mildew growth. This will keep your system smelling great and operating at full efficiency. 

Follow this procedure for a consistent mini-split ductless system maintenance program.  

If you didn’t want to use a water collection bag, use a spray bottle that can mist the water.  This will help prevent overflow of the drain pan. If you didn’t want to use a water collection bag, use a spray bottle that can mist the water.  This will help prevent overflow of the drain pan.