I still marvel at how I went about my second air filter replacement. The first one went okay because I followed the instructions keenly. The second time, however, I disregarded the instructions altogether. I was confident in my non-existent skills. I put it backward, and in return, my actions resulted in poor indoor air quality. I could not understand why the air quality had been deteriorating. The cooling equipment also became noisier, and I had to call for a/c service from the local cooling company. When the cooling technician inspected, she found the mistake that I had made. The error caused several damages to the smart HVAC. My saving grace was that I had a separate air purification system. My mistake also caused a lot of dust to circulate in the ductwork, so it was necessary to have duct cleaning. The cooling expert showed me step-by-step how to replace a filter. Given the simplicity of the procedure, I don’t understand how I messed it up. The cooling specialist also showed me some a/c setup care and energy-saving tips. If I could have let the issue persist a little longer, the damage to the climate control unit would have been extensive, resulting in expensive repairs. I had learned my lesson the hard way and had vowed to take better care of my HVAC system, including annual HVAC maintenance, for it to run better and to last longer. I learned to pay attention to simple cooling technology instructions and always to confirm when uncertain about something.