Spring came early this year, and the weather warmed up very quickly. After a long winter, with the windows shut tight and the furnace blasting non stop, I was looking forward to getting some fresh air. I hoped to enjoy at least a couple of months without running either the heating or cooling system. Instead, the temperature climbed up into the upper seventies almost over night. The humidity was particularly bad, and the whole house felt overheated and sticky. I lowered the thermostat, started up the air conditioner, but never even considered scheduling professional maintenance. There was a great deal of work to do around the house. I was busy putting away snow shovels and wool coats, and setting up patio furniture and the barbecue grill. The air conditioner operated just fine for nearly six weeks. I then noticed it running for much longer cycles but failing to meet demand. No matter how I adjusted the thermostat, the house still felt overly warm. I suddenly needed to clean far more often, because there was a great deal of dust circulating in the air. My monthly electric bill was extremely high. I finally got around to hiring a licensed HVAC contractor to provide a thorough cleaning and tuning of the cooling unit. The technician found a large buildup of contaminants within the inner workings, which were blocking air flow. He explained that the restricted airflow was causing the air conditioner to work much harder and putting needless strain on components. Had I waited much longer, the air conditioner might have frozen up and quit completely.