The answer to 'why is my ductless system high energy bills' is that there are several common causes, including improper sizing, air leaks, dirty filters, and inefficient compressors. Ductless systems that are not properly matched to the size of the space they are cooling can use excessive energy, as can systems with leaks in the refrigerant lines or air handlers. Dirty air filters reduce airflow and make the system work harder, while old or inefficient compressors also contribute to high energy usage.
In many cases, these issues can be addressed through DIY maintenance like cleaning filters and sealing leaks. However, if the system is improperly sized or has more complex problems, it's best to call in a professional HVAC technician to diagnose and resolve the issue.