These systems are great ways to heat and cool a home. Good systems can provide heat in a home to -20 degrees Fahrenheit, and cooling to 100 degrees effectively. I love the concept of mini split systems. They are the most efficient manner of heating and cooling using electricity use, and they don’t use fossil fuels. However, they are very challenging when it comes to mold growth. Here’s why:

Moisture builds up:

Since mini splits have direct access to outside air, condensation creation is a reality. The absence of ductwork in the mini split head can lead to moisture buildup within the unit itself. 

Accessibility and size of the mini split head:

The units are not easily accessible. This is because they are usually installed high on the wall, and the unit itself is not easy to disassemble. Also, there are little crevices (greatest areas for microbial growth) that are not easy to access, or even visible on most units. 

The lack of air circulation:

Unlike a traditional HVAC system, which moves air through ducts to each room, and then returns it to the air handler through return air vents, mini splits produce air from one place. While a traditional HVAC is consistently moving air through the unit itself, a mini split blows air around much like a common fan but lacks the capacity to move air into and out of the room.