If you don't understand your HVAC system, you will not be able to maintain it. For very long, I didn't have the first idea about my HVAC system. The system would sometimes shake and make strange noises. Other times, the HVAC system would blow out warm air rather than cold. I wasn't very happy about this but I didn't know what to do. In the end, I had to contact an HVAC contractor so I could ask for help. The contractor soon had my HVAC system working perfectly. I've started this blog in the hope that it will help you to understand your HVAC system.